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Anatomy Holy Bible - 1st Semester

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    Back and Shoulder

    Occipital n., C2A purely cutaneous nerve

    Suboccipital n.A motor nerve, lying deeper in the triangle

    Trapezius m.Attaches at the level of T12

    Nerve: spinal component of the spinalaccessory n., CN XI, seen on the anterioraspect of the trapezius m.

    This nerve also innervates the

    sternocleidomastoid m.Blood: superficial branch of the transverse

    cervical a.

    Action: elevate, retract and rotate the scapula

    Abducts above 90 degrees

    Lesion: cant elevate (shrug) shoulder

    These 3 muscles have the same nerve and blood

    supplyLevator scapulae m.

    Attaches C1-C4

    Rhomboid minor m., comes off opposite the

    spine of the scapula, T3Attaches C7-T1

    Rhomboid major m.

    Attaches T2-T5

    Rhomboids let you stick your chest out

    Nerve: dorsal scapular n.Seen on the anterior aspect of the scapula

    Blood:deep branch of the transverse

    cervical a.Accompanies the nerve to these muscles

    Serratus posterior superior m., lies under therhomboids

    Latissimus dorsi m.Inserts into the floor of the intertubercular

    groove

    Action: hand-cuff position

    Powerful adductor of humerus.

    Nerve: thoracodorsal n.from the posteriorcord of the brachial plexus

    Serratus posterior inferior m., lies under thelatissimus dorsi

    Erector spinae m.

    Spinalis m., closest to the spine

    Longissimus m., in the middle, goes all the

    way to the mastoid process

    Iliocostalis m., most lateral, from iliac crest tothe ribs

    Rotator cuff muscles, SITS

    Supraspinatus m.

    Infraspinatus m.

    Teres minor m.

    Subscapularis m.

    Supraspinatus m.Action: 1

    st15 degrees abduction

    Nerve: suprascapular n.

    Runs below the suprascapular ligament,which is suspended over the suprascapular

    notch

    Blood: suprascapular a.Runs above the suprascapular ligament,

    which is suspended over the suprascapular

    notch

    Suprascapular a. arises most commonly from

    the 1stpart of the subclavian a., or

    occasionally from the 2nd

    or 3rd

    part

    Army over the bridge, Navy under the bridgeArtery runs above the suprascapular ligament

    Nerve runs below the suprascapular ligament

    Attaches on the highest facet of the greatertuberosity of the humerus

    Injury of supraspinatus m.Inserts under the acromion, thus it is the most

    commonly torn in a rotator cuff injury

    The tendon passes under the acromion. Onecan develop bony spurs on the under side of

    the acromion, which will start to tear away

    the tendon, until eventually the tendonruptures

    Loss the first 15 degrees of abduction, soperson will hang the shoulder down to let

    gravity allow them to overcome the first 15

    degrees, then they can use the deltoid andtrapezius to abduct the arm the rest of the

    way

    Infraspinatus m.Nerve: suprascapular n., like

    the supraspinatus m.

    Attaches on the middle facet of the greatertuberosity of the humerus

    Action: laterally rotates humerus, a muchstronger lateral rotator than teres minor m.

    Teres minor m.

    Action: laterally rotates humerusAttaches on the inferior facet of the greater

    tuberosity of the humerus

    Nerve: axillary n.

    Action: laterally rotates humerus

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    Teres major m.Action: medially rotates humerus, as doespectoralis major and latissimus dorsi

    Attaches at the medial lip of the

    intertubercular groove

    Pectoralis m. attaches at the lateral lip of theintertubercular groove

    Latissimus dorsi attaches in the floor of the

    intertubercular grooveNerve: lower subscapular n., C6, C7

    Deltoid m.

    Abducts 15-90 degrees: lateral fibers do

    Abduction

    Nerve: axillary n.from the posterior cord ofthe brachial plexus

    Anterior fibers flex the humerus

    Posterior fibers extend the humerus

    Know the attachments of every muscle on the

    scapula (see Bony Landmarks)SpacesBack and Shoulder

    Quadrangular space

    Bounded by:

    Subscapularis tendon superiorly

    Teres major tendoninferiorly

    Long head of the triceps brachii m.medially

    Humeruslaterally

    Passing through the quadrangular space are the:Axillary n., turns superiorly

    Posterior circumflex humeral a., runs across

    laterally to muscle

    Clinical:

    Surgical head fracture of humeruswill most

    likely damage the contents of the quadrangular

    spaceTo test for axillary n. damage, do muscle testfor deltoid, which is the major abductor of

    the arm

    Triangular interval

    Bounded by:

    Teres major m.superiorlyLong head of the triceps brachii m.medially

    Humerus laterally

    Passing through the triangular interval are the:

    Radial n.,

    Profunda brachii a.

    Clinical:Mid-humeral fracture will most likely

    damage the contents of the triangular interval

    If the radial n. is damaged, it can cause wrist

    drop

    To test for radial n. damage, do muscle test forextensor muscles of elbow and wrist

    Triangular space

    Bounded by:Teres minor m.superiorly

    Teres major m.inferiorlyLong head of the triceps brachii m.laterally

    Passing through the triangular space are the:

    Circumflex scapular a. and v.

    Theres NO nerve in this space

    Triangle of auscultation

    Location:Near inferior angle of scapula on lower medial

    border of scapula

    Bounded by:

    Trapezius m.mediallyRhomboideus major m.superiorly

    Latissimus dorsi m.inferiorly

    Clinical:Use this space to listen to (auscultate) lungs

    since the stethoscope can be placed close to

    the thoracic wall at this location, withminimum impedance of sound through muscle

    Lumbar triangle = Triangle of Petit

    Bounded by:

    Latissimus dorsi m.medially

    External abdominal oblique m.laterallyIliac crestinferiorly

    Notes:Its floor is the internal abdominal oblique m.

    May be the site of an lumbar hernia

    Spinal Cord

    Dura matter, extends to S2

    Epidural space, above the dura matterThere will be probe inserted into the space in

    exam

    Between the dura matter and the bone of thevertebrae

    Contains fat and blood vesselsClinically important

    Subdural space, between dura and arachnoidmatter

    Clinically not very significant

    Arachnoid matter, a filmy layer under the duramatter

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    Subarachnoid space, between arachnoid andpia matter

    Clinically very important

    Contains cerebral spinal fluid

    Conus medullaris, the end of the spinal cordEnds at the level of the intervertebral space

    between L1-L2 in adults

    End at L3 in newborn

    Filum termminale internum, an extension ofpia matter within the vertebral column

    Called the externum when it exits the sacral

    canal

    Cauda equina

    Denticulate ligaments, tooth-like processes of

    pia matterThey separate the dorsal rootlet from the

    ventral rootlet, a reference used in surgeryDorsal rootlet is above the denticulate

    ligament

    Ventral rootlet is deep to the denticulateligament

    Prevents the spinal cord from swishing in the

    dural sac in the spinal canal

    They end at the level of T12-L1

    Dorsal rootlet, purely sensory

    Ventral rootlet, purely motor, deeper than the

    dorsal rootlet

    Dorsal root ganglion, a bulge of nerve sittingoutside of the dural sac

    Spinal nerve, formed by the joining of theventral and dorsal rootlet immediately after thedorsal root ganglion

    Immediately after forming a spinal nerve, itdivides into

    Dorsal rami

    Ventral rami,much larger

    Upper Limb

    Cephalic v.Originates on the lateral aspect of the

    dorsum venous archof the hand

    In the shoulder region, it can be seen draining

    into the axillary v.in the deltopectoralgroove

    Brachial plexus

    Formed by the joining of ventral rami from C5-

    T1

    The divisions are Rodney Thomas Drinks ColdBeer

    Roots

    Trunks

    Divisions

    Cords

    Branches

    There are 5 roots, from ventral rami of C5, C6,

    C7, C8, T1

    There are 3 trunksformed by merging of roots

    Superior trunk, formed from C5 and C6

    Middle trunk, formed from C7

    Inferior trunk, formed from C8 and T1

    Upper trunk palsy, an injury to the uppertrunk, C5, C6, is very serious: Erbs Palsy

    (Waiters tip)Suprascapular n., C5, C6, which supplies 2muscles

    Supraspinatus m., abduct 0-15 degrees

    Infraspinatus m.

    Axillary n., C5, C6, which supplies 2muscles

    Deltoid m., abducts 15-90 degrees

    Teres minor m.

    Musculocutaneous n., C5, C6, whichsupplies 3 muscles

    Brachialis m.Biceps brachii m.Coracobrachialis m.

    Functionally, you would lose

    Abduction from 0-90 degrees

    You would NOT lose

    Flexion of the elbow because there are

    many other flexorsSupination, but it would begreatly

    weakenedfrom loss of biceps brachii

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    Lower trunk palsy, an injury the lower trunk,

    C8, T1Mimics an injury to the ulnar n. from injury

    to the medial epicondyle

    Patient presents withClaw hand

    Abducted wrist from loss of wrist adduction

    Klumpkes palsy

    Each trunk divides into 2 divisions

    Anterior divisionsare the flexor part

    Posterior divisionsare the extensor part

    CordsForm from merged divisions

    Named for their spatial relationship with the2

    ndpart of the axillary a.,which is underneath

    pectoralis minor m.

    Posterior cordSits posterior to the 2

    ndpart of the axillary a.,

    Formed from all 3 posterior divisions of the 3

    trunks

    Lateral cordSits lateral to the 2

    ndpart of the axillary a.

    Formed from anterior divisions of superiorandmiddle trunks

    Medial cordSits medial to the 2

    ndpart of the axillary a.

    Formed from the anterior division of the

    inferior trunk

    Terminal branchesfrom the cords

    During the test, be sure to first determine which

    cord the nerve is coming from, determine if thecord is lateral, medial, or posterior relative to

    the axillary a.

    a. Lateral cordHas 3 branches, from superior to inferior

    1. Lateral pectoral n.Innervates the pectoralis major m.

    2. Musculocutaneous n.

    Called musculocutaneous because itsupplies 3 muscles of the arm muscles andthen becomes cutaneous for the lateral

    forearm

    Pierces through the coracobrachialis m.ID by this feature

    Runs between the biceps brachii m. and

    thebrachialis m.

    Becomes cutaneous at the forearm,becoming the lateral cutaneous n. of the

    forearm= lateral antebrachial cutaneousn., at the cubital fossa

    Travels down to the wrist on the lateralaspect of the forearm

    Innervates 3 muscles, all flexors of the arm

    Coracobrachialis m.

    Biceps brachii m.

    Brachialis m.

    3. Median n., lateral root

    The lateral root of the lateral cord uniteswith the medial root of the medial cord to

    form the median n.

    Seen running directly down the midline ofthe arm, toward the cubital fossa

    Innervates all flexor muscles of the

    forearm, EXCEPT

    1 muscles which are innervated by the

    ulnar n.

    Flexor carpi ulnar m.Flexor digitorum profundus m.,

    medial 1/2

    1 muscle which is innervated by the

    radial n.

    Brachioradialis m.

    Even though, it can be seen passing throughthe arm, the median n. does NOT innervateanything in the armonly the forearm and

    hand

    b. Medial cord

    Has 5 branchesThe first 2 are cutaneous nerves that branchoff above the M-shape of the nerves

    The middle 2 do NOT supply the arm, buthave functions in the forearm and hand

    The last 1 goes to pectoralis major and

    minor

    1. Medial cutaneous n. of forearm =

    Medial antebrachial cutaneous n.

    Thicker and longer of the 2, which goes

    all the way to the forearmSeen passing next to the ulnar n., the more

    lateral of the 2

    A cutaneous nerve of the forearm

    2. Medial cutaneous n, of arm = Medial

    brachial cutaneous n.Much thinner and shorter branch, which

    stops at the cubital fossa

    Seen as the more medial of the 2

    A cutaneous nerve of the arm

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    3. Median n., medial root

    The medial root of the medial cord uniteswith the lateral root of the lateral cord to

    form the median n.

    Seen running directly down the midline ofthe arm, toward the cubital fossa

    Innervates all flexor muscles of the

    forearm, EXCEPT

    1 muscles which are innervated by theulnar n.

    Flexor carpi ulnar m.

    Flexor digitorum profundus m.,

    medial 1/2

    1 muscle which is innervated by the

    radial n.

    Brachioradialis m.

    Even though, it can be seen passing through

    the arm, the median n. does NOT innervate

    anything in the armonly the forearm andhand

    4. Ulnar n., C8, T1Inner leg of the M

    Seen running down the medial aspect of the

    arm, and passing behind the medial

    epicondyle of the humerusID by this

    feature

    Even though, it can be seen passing throughthe arm, the ulnar n. does NOT innervate

    anything in the armonly the forearm and

    handInjury to the medial epicondyle, can injure

    the ulnar n., and patient would present withClaw hand

    Abducted wrist from loss of wrist

    adduction

    5. Medial pectoral n.Innervates

    Pectoralis minor m., pierces through this

    muscle to reach pectoralis major m.

    Pectoralis major m.

    Thinner than antebrachial n.

    Stops in cubital fossa

    c. Posterior cordYou need to know all the branches comingoff the posterior cord

    For ID, the other 2 cords (lateral and medial)will have to be pinned back to one side to

    expose the posterior cord, which is a big clue

    that youre looking at the posterior cord and

    its branches

    Has 5 branchesThe first 3 are small branches that come offearly

    The last 2 are large branches further down

    From superior to inferior the branches of the

    posterior cord are

    1. Upper subscapular n.1

    stbranch, comes off posteriorly

    Innervates subscapularis m., which is also

    innervated by the lower subscapular n.

    2. Thoracodorsal n.(used to be called themiddle subscapular n.)

    A long nerve seen running down to the

    latissimus dorsi m.Innervates the latissimus dorsi m.

    3. Lower subscapular n.

    InnervatesTeres major m.

    Subscapularis m., inferior part

    The only muscle that inserts on thelesser tuberosity of the humerus

    Is part of the rotator cuff

    Has dual innervationmust name bothon exam

    Upper subscapular n.

    Innervates only the subscapularis m.

    Lower subscapular n.

    Innervates 2 muscles: subscapularism. and teres major m.

    The posterior cord then divides into the

    following 2 terminal branches

    4. Axillary n.Seen as large branch that immediately dives

    posteriorly

    Runs through the quadrangular space,accompanied by the posterior circumflex

    humeral a.

    Runs around the surgical neck of thehumerus

    Innervates

    Deltoid m.

    Teres minor m.

    Branches: Upper Lateral Cutaneous

    Nerve of the Arm

    Dislocation of the shoulderis alwaysanterior and inferior, and would injury the

    axillary n.not the radial n.

    Sensory loss

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    Over the shulder, remember the

    regimental sign where loss is at andabove the level of military stripes on the

    sleeve

    When popping the shoulder back intoplace, to avoid a lawsuit, make sure yousensory test first before you touch the arm

    at all! Then pop the shoulder into place,

    and sensory test again!If you dont document sensory lossbefore

    you do the adjustment, you can be sued

    when patient later claims that you causedthe sensory loss during the adjustment

    Fracture of the surgical neckof thehumerus would injure the axillary n. and

    the posterior circumflex humeral a.. Nerve

    damage would cause

    Sensory loss: regimental sign

    Motor loss

    Deltoid paralysis, thus loss off abductionbetween 15-90

    Teres minor m. cant be clinically tested,

    but it is a lateral rotator, thus weakend

    lateral rotation

    5. Radial n.Runs through the triangular intervalof the

    arm where it is accompanied by the

    profunda brachii a., the 1stbranch off the

    brachial a.

    Both nerve and artery can be seen on theposterior arm when the lateral and long

    heads of the triceps are spread apart

    Fracture in the midshaft of the humeruswould injure the radial n. and the profunda

    brachii a.. Nerve damage would causeWrist droponly extension of the wrist is

    lost

    Has the person lost the ability to extendthe shoulder or elbow? No, because the

    radial n. gives off branches to the triceps

    much earlier than when it goes to thespiral groove

    Branches: Lower Lateral Cutaneous

    Nerve of the Arm, Posterior Cutaneous

    Nerve of the Forearm, posterior Cutaneous

    Nerve of the Arm

    Other nerves of the axilla region

    These nerves are direct branches from theventral rami, not from one of the brachial plexuscords

    Dorsal scapular n.From ventral ramus C5

    Innervates:

    Levator scapulae m.

    Rhomboid minor m.Rhomboid major m.

    Long thoracic n.From ventral rami of C5, C6, C7

    Seen running along the surface of the serratus

    anterior mm.

    Innervates: serratus anterior m.

    C5, C6, C7: raise your arms to heaven

    Injury to the long thoracic n. results in loss ofprotraction of the scapula, causing a wingedscapula

    Vessels of the arm

    Axillary v.runs above the axillary a.

    Axillary a.Is seen when the axillary v.is reflected back

    Begins at the lateral border of the 1strib

    Ends at the inferior border of teres major m.,where it becomes the brachial a.

    Has 3 regions defined by their relationship to

    pectoralis minor m.

    The 1stpart has 1 branch

    The 2ndpart has 2 branches

    The 3rd

    part has 3 branches

    1stpart of axillary a.

    Between the lateral border of the 1striband

    the medial border of the pectoralis minor

    m.

    Has 1 branchSupreme (Superior) thoracic a.wont

    be testedA tiny branch that extends to the upper

    thoracic wallSupplies 1

    stand 2

    ndICS and superior

    part of serratus anterior m.

    2nd

    part of axillary a.

    Posterior to (underneath) pectoralis minor

    m.

    Has 2 branchesThoracoacromial trunk:- Pierces the

    clavicopectoral fascia before giving off

    4 branches, CAPD

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    Clavicular branch

    Acromial branch

    Pectoral branches, the only identifiable

    branches

    Deltoid branch

    Lateral thoracic a.Follows the border under the pectoralis

    minor m.

    Can be seen entering the thoracic wall

    Supplies the pectoralis mm., axillarylymph nodes, and breast

    3rd

    part of axillary a.

    Between the lateral border of the pectoralis

    minor m.and the inferior border of the

    teres major m.

    Has 3 branches: 2 lateral branches and 1medial branch

    The 2 lateral branches are

    Anterior circumflex humeral a.Tiny branch that sits above the muchlarger posterior circumflex humeral a.

    Runs to the anterior aspect of thehumerus

    Posterior circumflex humeral a.

    Much larger branch than the anteriorcircumflex humeral a.

    Runs to the posterior aspect of thehumerus

    Through the quadrangular space,accompanied by axillary n.

    The 1 medial branch

    Subscapular a., the largest branch of the

    axillary a., which divides into 2 branches

    Circumflex scapular a.A much larger branch than the

    thoracodorsal a.

    Passes behind the scapula to its dorsal

    aspect

    Very important for collateral

    circulation around the scapulaAppears in the triangular spaceof the

    scapula, between the teres minor m.

    and teres major m.

    Thoracodorsal a.The continuation of the subscapular a.,Seen running down toward the

    latissimus dorsi m.

    Accompanied by the thoracodorsal n.

    If the medial branch is tagged before itstarts to branch, you would saysubscapular artery

    If the medial branch is tagged after itbranches then it will either be

    Thoracodorsal a., seen runningdownward to the latissimus dorsi m.

    Circumflex scapular a., a much thicker

    branch seen going immediately behindthe scapula

    Brachial a.Begins at the point where the axillary a. passes

    the inferior border of the teres major m.

    In the arm, the brachial a. gives off a branch

    Profunda brachii a.The 1

    stbranch off the brachial a.

    Anterior branch anastomose with

    radial recurrent branch of radial artery

    in front of lateral epicondyle

    Posterior branch anastomose withinterosseous recurrent branch of the

    posterior interosseous artery behind the

    lateral epicondyle

    Runs through the triangular intervalof the

    humerus, accompanied by the radial n.

    In the cubital fossa, the brachial a. dividesinto

    Radial a., which runs laterally along theradial side of forearm

    Ulnar a., which runs medially along the

    ulnar side of the forearm

    Lymph nodes

    central lymph nodes are defined asthe group of lymph nodes situated

    deep to the pectoralis minor at thebase of the axilla

    apical lymph nodes are medial to themedial border of the pectoralis minor

    subscapular nodes are found on theposterior wall of the axilla

    Nerves of the Arm

    Musculocutaneous n.

    Called musculocutaneous because itsupplies

    3 muscles of the arm muscles and thenbecomes cutaneous for the lateral forearm

    Innervates 3 muscles, all flexors of the arm

    Coracobrachialis m.

    Biceps brachii m.

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    Brachialism.

    Pierces through the coracobrachialis m.

    Runs between the biceps brachii m. and the

    brachialis m.

    At the cubital fossa, it becomes the lateral

    cutaneous n. of the forearm= lateralantebrachial cutaneous n.

    Travels down to the wrist on the lateralaspect of the forearm

    Radial n.From posterior cord of brachial plexus

    PathwaySits in the spiral grooveof the humerus,

    seen between the long head and lateral head

    of the triceps m.

    Accompanied by the profunda brachii a.inarm

    Enters cubital fossa

    Volkmanns contracture: damage to thebrachial artery at distal end of humerus.

    Innervates

    Triceps brachii m.

    Anconeus m.

    Median n.Does not innervation anything in the arm, only

    the forearm

    Muscles of the arm

    Subscapularis m.Attachments:

    Subscapular fossa

    Lesser tuberosity of the humerus

    The only muscle that inserts on lesser

    tuberosity of humerus

    Action:Medially rotates arm

    Adducts arm

    Holds humeral head in glenoid fossa as part

    of rotator cuff

    Nerve: has dual innervationif asked for itsinnervation on exam, you must name bothnerves

    Upper subscapular n., C5, C6, C7

    Innervates only the subscapularis m.

    Lower subscapular n., C5, C6, C7Innervates 2 muscles: subscapularis m. and

    teres major m.

    Coracobrachialis m.Attachments:

    Coracoid process

    Midshaft of the humerus, just lateral to thedeltoid tuberosity

    Action: adduct and flex the shoulderMuscle used to tuck a newspaper under your

    arm against your ribs

    Nerve: musculocutaneous n., C5, C6, C7

    Biceps brachii m.Has 2 heads, the long head is more medial

    The Long head is Lateral, and has a Longtendon which runs through the

    intertubercular (bicipital) groovein the

    head of the humerus

    The short head is more medial since it

    attaches to the coracoid process

    If you see one head tagged for ID, you needto specifically identify that head

    If the tag is in the muscle belly, then you

    would say biceps brachiiAttachments:

    Short head: coracoid process

    Long head: supraglenoid tuberosity

    Radial tuberosityof the radius

    [Long head of tricepsattaches at theinfraglenoid tuberosity]

    [Coracobrachialis m.and pectoralis

    minor m.also attach on the coracoidprocess]

    Action:

    Supinates the forearmthe strongestsupinator

    If asked which muscle is the strongestsupinator in the upper limb, you would say

    biceps brachiiNOT the supinator

    muscle

    If asked what is the strongest action ofbiceps brachii, you would say supination

    Long head flexes the shoulder (and some

    elbow), since it crosses both shoulder and

    elbow jointsShort head flexes the elbowonly, since it

    only crosses the elbow

    Biceps brachii is our wine-opening

    muscleunscrews the cork then pulls it outof the bottle

    Nerve: musculocutaneous n., C5, C6, C7

    Brachialis m.Lies under the bicep brachii m.

    Attachments:

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    Midshaft of the humerus

    Coronoid processof the ulnaNOTcoracoid

    Ulnar tuberosity

    Action:purely a flexor of the elbowDoes NOT cross the shoulder joint, thus it

    has no action on the shoulder

    Does NOT go to the radius, thus it cannot

    pronate or supinateNerve: musculocutaneous n., C5, C6, C7

    TricepsHas 3 heads

    Long head

    Is most medial

    Attaches to the infraglenoid tuberosity

    [Long head of biceps brachiiattaches tothe supraglenoid tuberosity]

    Lateral head

    Lies over the spiral grooveProximal and lateral to the spiral grooveofthe humerus, which has the radial n.and

    profunda brachii a.in it

    Medial headDeeper, seen when long and lateral heads

    are separated apart

    Distal and medial to the spiral grooveof

    the humerus, which has the radial n.and

    profunda brachii a.in it

    Radial n. and profundi brachii a. are seen when

    the laternal and long heads of the triceps arespread apart

    If there is a midshaft fracture of the humerus,

    it would injure the radial n.and profunda

    brachii a.

    The 3 portions come together in a commontendonand attach to the olecranon of the ulna

    Action: one of the chief extensors of the elbow

    Fracture or avulsion of the olecranon process

    would cause off of the triceps attachement,

    thus loss of extension of the elbowAnconeus m.

    A small, relatively unimportant triangular

    muscle

    Usually blends with the triceps near the elbow

    Lies partly over the supinator on the proximal

    ulna

    Action: helps extend the forearm

    Forearm

    To orient yourself on the forearmLook for the thumb side, which is the radialor

    lateralside

    Look for the little finger, which is the ulnarormedialside

    Use the brachioradialism. as a landmarkIt sits between the flexor and extensor

    compartments

    You can figure out the other muscles relativeto the brachioradialis

    Cubital fossa

    From lateral to medial: TANtendon, artery,nerve

    Lateral: tendon of biceps brachii, which

    attaches to the radial tuberosity

    Middle: brachial a.

    Medial: medial n.median is medial

    Important orientation for taking blood pressure.Ask patient to flex the forearm, feel for thetendon of biceps brachii, and just lateral to that

    you feel the pulsation of the brachial artery

    Vessels of the forearm

    Cephalic v.

    Superficial vein

    Begins on the lateral aspect of the dorsalvenous networkof the hand

    Ascends along the anterolateral surface of the

    forearm and arm

    Anterior to the elbow it communicates withthe median cubital v.

    Courses along the deltopectoral grooveand

    enters the deltopectoral trianglewhere itpierces the clavipectoral fasciaand joins the

    axillary v.

    Basilic v.Superficial vein

    Begins on the medial aspect of the dorsal

    venous networkof the hand

    Ascends along the medial aspect of theforearm and inferior aspect of the arm

    Communicates with the median cubital v.

    anterior to the elbow

    Passes deeply, piercing the brachial fasciaand runs parallel to the brachial a.to the

    axilla, and joins the axillary v.

    Median cubital v.

    Superficial vein, passing anterior to the cubitalfossa

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    Joins the cephalic v.(more lateral) with thebasilic v.(more medial)Common site for venipuncture

    If needle pierces through the vein it cancontact the median n.

    Medial antebrachial cutaneous is slightly

    medial to the medial cubital vein and could

    be injured by a needle. If the needle had

    gone laterally, it might have injured thelateral antebrachial cutaneous nerve

    Arteries of the forearm

    Brachial a.divides into 2 arteries at the cubital

    fossa

    Radial a.Runs laterally along the radial side of

    forearm toward the thumbRuns through the anatomical snuff box

    Then pierces through between the 2 heads of

    the 1st dorsal interossei m.Then it forms most of the deep palmar arch

    Ulnar a.Tends to be substantially larger than the

    radial a.

    Runs medially along the ulnar side of the

    forearm toward the little finger

    Gives off a short trunk called the common

    interosseus trunk, which soon gives off 2branches

    Anterior interosseus a.

    Seen running on top of the interosseusmembrane

    Accompanied by the anteriorinterosseus n., from the median n.

    Posterior interosseus a.From the ventral aspect, seen going deep

    into the extensor compartment

    Runs w/ deep branch of radialnerve.

    Continues down the forearm, accompaniedby the ulnar n.

    The ulnar a. and ulnar n. cross the wristabove the flexor retinaculum, through

    Guyons canal, to the palm of the hand

    where it forms the ulnar a. forms the

    superficial palmar archSuperior and inferior ulnar collateralarteries contribute to the collateralcirculation of the elbow on its medial aspect.

    The superior ulnar collateralanastomoses with the posterior ulnarrecurrent artery (branch of ulnar) behind

    the medial epicondyleThe inferior ulnar collateral

    anastomoses with the anterior ulnarrecurrent artery in front of the medialepicondyle.

    Nerves of the Forearm

    Median n.

    From the lateral (C6, C7) and medial (C8, T1)cords of brachial plexus

    Innervates all the muscle of the forearm,EXCEPT

    1 muscles which are innervated by the

    ulnar n.

    Flexor carpi ulnaris m.

    Flexor digitorum profundus m., medial

    PathwayEnters cubital fossa medial to the brachial a.

    Passes between heads of pronator teres

    Descends between flexor digitorumsuperficialis and flexor digitorum profundus

    Passes through carpal tunnelto reach hand

    Gives off a branch to the thenar eminence,recurrent branch of median n., C8, T1

    Gives off 2 branches, seen in the ventral aspect

    of the forearm

    1. Anterior interosseous n.Branches from median n. in the distal

    cubital fossa

    Accompanied the anterior interosseus a.on the surface of the shiny interosseus

    membrane

    Supplies motor to deeper muscles of the

    forearm

    Flexor digitorum profundus m., lateral

    Flexor pollicis longus

    Pronator quadratus

    2. Palmar cutaneous branch of median n.Branches from median n. just proximal to

    flexor retinaculumPasses between tendons of palmaris longus

    and flexor carpi radialis

    Runs superficial to flexor retinaculum

    Supplies cutaneous to palm

    Ulnar n.Accompanied by the ulnar a., a branch of the

    brachial a.

    Only supplies motor to 1 muscles of the

    forearm

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    Flexor carpi ulnaris m.

    Flexor digitorum profundus m., medial

    Plays a much larger role in the hand

    Radial n.

    From posterior cord of brachial plexus

    Innervates all the extensor muscles of theforearm, PLUS one flexor, the

    brachioradialis m.Pathway

    Sits in the spiral grooveof the humerus,

    seen between the long head and lateral head

    of the triceps m.

    Accompanied by the profunda brachii a.inarm

    Enters cubital fossa

    Descends between brachialis m. andbrachioradialis m.

    At the level of the lateral epicondyle of

    humerus, it divides into superficial and deepbranches

    Gives off 2 branches, best seen on dorsalaspect of the forearm

    1. Superficial branch of the radial n.

    The thinner of the 2 branches of the radialn., which branch just superior to the

    supinator m.

    Best seen emerging at the lateral wrist,where it crosses over the anatomical snuff

    box to the dorsum of the lateral hand

    Purely a cutaneous nerve to dorsum of thehand on its lateral aspect, thumb and first

    few fingers

    Pathway

    Passes anterior to pronator teres m.

    Passes under the brachioradialis m.

    Crosses over the anatomical snuff boxasit passes to the superficial aspect of the

    dorsum of the hand

    2. Deep branch of the radial n.

    The largest of the 2 terminal branchesSupplies motor innervation to posteriorcompartment

    PathwayArises from radial n. just distal to the

    elbow

    Pierces the supinator m.ID by thisfeature

    Winds around the lateral neck of theradius

    After is pierces the supinator m. itbecomes the posterior interosseus n.

    It reaches the wrist joint andcarpal bones for proprioceptive

    sense from these structures

    Accompanied by the posterior

    interosseus a.from the commoninterosseus trunk of the ulnar a.

    If this nerve is tagged before dividing intoits superficial and deep branches, you

    would say radial n.

    If this nerve is tagged after dividing into itssuperficial and deep branches, but before

    piercing the supinator m., you would saydeep branch of the radial n.

    If this nerve is tagged after piercing thesupinator m., you would say posterior

    interosseus n.

    Note:Both the anterior and posterior interosseus

    arteries are from thesamesource, the common

    interosseus trunkfrom the ulnar a.

    The anterior and posterior interosseus nervesare from differentsources

    Anterior interosseus n.is from the median

    n.Posterior interosseus n.is from the radial

    n., the continuation of the deep branch of the

    radial n. after it exits the supinator m.

    Flexor compartment of the forearmContains the flexors and pronators of the

    forearm

    All muscles in this forearm compartment areinnervated by the median n.and/or ulnar n.

    EXCEPT

    Brachioradialis m.is innervated by the radial

    n.

    Median n.innervates all but 1 muscles

    Ulnar n.innervates 1 muscles

    Flexor carpi ulnaris m.

    Flexor digitorum profundus m., medial

    (ulnar

    The anterior compartment communicates withthe central compartment of the palmthrough

    the carpal tunnel

    Generally the fascial compartments of thelimbs usually contain fluids and infections,

    thus preventing spread to other compartments

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    The anterior compartment of forearm is anexception due to its communication with thecentral compartment of the palm

    Common flexor tendonattached to the medial

    epicondyleAvulsion or fracture of the medial epicondyle

    would effect the flexors of the forearm

    Common extensor tendonattaches to the

    lateral epicondyle

    Interosseous membraneShiny, silvery membrane between radius andulna

    From lateral to medial at the anterior wrist areAbductor pollicis longus m. (not a flexor, but

    most lateral)

    Brachioradialis m. (doesnt cross wrist, ends at

    distal radius)Radial a.

    Flexor carpi radialis m.

    Flexor pollicis longus m.Median n.

    Palmaris longus m : Gives off Palmar

    aponuerosis

    If damages, we getDuputyrens contracture.

    Palmar aponeurosis goes overcarpul tunnel.

    Flexor digitorum superficialis m. (2 of the 4

    tendons)Ulnar a.

    Ulnar n.

    Flexor carpi ulnaris m.

    Brachioradialis m.Superficial muscle coming from lateral elbow

    Attachments:Proximal 2/3 of lateral supracondylar ridge

    of the humerus

    Lateral surface of distal end of the radius

    NOTE: it does NOT cross the wrist

    Action:

    Holds hand between pronation andsupination, hand shaking position (palmfacing medially)

    Flexes elbow, only when it in handshaking position

    Brachioradialis is our beer drinking

    muscle

    Condition equivalent to tenniselbow, this muscle is involved.

    Commonly involved in collesfracture coz it inserts into

    distal end of radius.Biceps brachii is our wine-opening

    muscle

    Nerve: radial n., C5, C6, C7

    This is the only flexor that is innervated by

    the radial n., which normally innervates the

    extensors

    Superficial flexor compartment

    Common flexor tendonCommon attachment on the medial epicondyle

    of the flexor muscles

    To help remember how the muscles are

    running in the superficial flexor compartment

    Turn your palm up, hook your thumb behind

    the medial epicondyle and spread your fourfingers over the forearm

    Index finger = pronator teres m.Middle finger = flexor carpi radialis m.

    Ring finger = palmaris longus m. (ifpresent)

    Little finger = flexor carpi ulnaris m.

    Flexor carpi radialis m.

    Extends from medial epicondyle to the thumb

    Its belly is just medial to brachioradialis

    Attachments:Medial epicondyle of humerus

    Base of 2ndmetacarpalAction: flexes and abducts hand at wrist

    Nerve: median n., C6, C7

    Radial pulse is lateral to this.Palmaris longus m.

    Extends from medial epicondyle to the centerof the wrist

    Its belly lies half under flexor carpi radialis m.

    Has a very small muscle belly with a long thintendon running to the middle of wrist

    When you pop up the tendons at the wrist,you see 2 tendons in the middle at the wrist

    The medial one of the 2 is the palmaris

    longus m.The lateral one of the 2 is the flexor carpi

    radialis m.

    10% of people dont have this muscle

    Similar to plantaris m.since it contributesvery little to function, and is excellent for

    doing tendon grafts

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    Attachments:Medial epicondyle of humerusDistal half of flexor retinaculum and palmar

    aponeurosis

    Action:Flexes hand at wrist

    Tightens palmar aponeurosis

    Nerve: median n., C7, C8

    Flexor carpi ulnaris m.

    Most medial of the superficial muscles

    Extends from the medial epicondyle to littlefinger side of wrist

    Has 2 heads: humeral and ulnar heads

    Attachments:Humeral head: medial epicondyle of humerusUlnar head: olecranon and posterior border

    of ulna

    Pisiform

    Hook of hamate5

    thmetacarpal

    Action: flexes and adducts hand at wrist

    Nerve: ulnar n., C7, C8

    Pronator teres m.

    The short muscle running from the medial

    epicondyle to under the brachioradialis m.

    Attachments:Medial epicondyle of humerusCoronoid process of ulna

    Middle of lateral surface of radiusAction: pronates forearm (turns palm

    downward) and flexes elbow

    Nerve: median n., C6, C7

    Deep flexor compartment

    Flexor digitorum superficialis m.Lies under flexor carpi radialis m. and

    palmaris longus m.

    Has 2 heads: humoroulnar and radial heads

    IDd byits 4 tendons passing under the flexor

    retinaculumAttachments:

    Humeroulnar head:

    Medial epicondyle of humerus

    Coronoid process of ulnaRadial head:

    Superior half of anterior border of radius

    Action: flexes fingers

    Nerve: median n., C7, C8, T1

    Flexor digitorum profundus m.

    Lies deep to flexor digitorum superficialis m.

    IDd by its 4 tendons passing under the flexorretinaculum

    Attachments:

    Proximal of medial and anterior surface of

    ulna and interosseous membraneBases of distal phalanges of medial 4 digits

    Action: flexes fingers, assists with flexion ofhand

    Nerve: has dual innervationMedial part:ulnar n., C8, T1

    Lateral part: median n., C8, T1

    If a tag is in the belly of this muscle and youare asked what is the innervation for this

    muscle?, you would say median and ulnar

    nerves

    If a tag is only in the lateral part, you wouldsay median n.

    Flexor pollicis longus m.Lies deep along the lateral aspect of ventral

    forearm

    Looks feathery

    Attachments:Anterior surface of radius and interosseous

    membraneBase of the distal phalanx of thumb

    Action: flexes thumb

    Nerve: anterior interosseous n.from mediann., C8, T1

    Pronator quadratus m.Lies in the proximal of forearm, deep to

    flexor digitorum profundus m. and flexor

    pollicis longus m.

    Attachments:

    Distal of anterior surface of ulnaDistal of anterior surface of radius

    Action: pronates forearm, binds radius andulna together

    Nerve: anterior interosseous n.from median

    n., C8, T1

    Extensor compartment of the forearm

    Contains the extensors and supinators of theforearm

    All muscles in this forearm compartment areinnervated by the radial n., directly or by its

    deep branch

    With palm down, orient yourself by locating the

    brachioradialis m.

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    Runs toward the thumb, as the most lateral

    muscle

    Its the only flexor muscle innervated by the

    radial n.

    From lateral to medial at the posterior wrist are

    Abductor pollicis longus m.Extensor pollicis brevis m.

    Extensor carpi radialis longus m.

    Extensor carpi radialis brevis m.Extensor pollicis longus m.

    Extensor indicis m. (under lateral extensor

    digitorum tendons)

    Extensor digitorum m. (4 tendons)Extensor digiti minimi m.

    Extensor carpi ulnaris m.

    Superficial extensor compartment

    Common extensor tendonCommon attachment on the lateral epicondyle

    of the extensor muscles

    Extensor carpi radialis longus m.Lies next to brachioradialis m.

    Its belly and long tendon lie over extensorcarpi radialis brevis m.

    Attachments:Lateral supracondylar ridge of humerus

    Base of 2nd

    metacarpal

    Action: extends and abducts hand at wrist

    Nerve: radial n., C6, C7

    On ID, you must write the full name of thismuscle, all 4 words

    Extensor carpi radialis brevis m.Lies underneath extensor carpi radialis longus

    m.

    Longus is always on top of brevis

    Attachments:Lateral epicondyle of humerusBase of 3rd metacarpal

    Action: extends and abduct hand at wrist

    Nerve: deep branch of radial n., C7, C8In classic tennis elbow, this muscle along w/Extensor digitorum is damaged.

    Extensor digitorum m.In the extensor compartment, there is NOsuperficialis or profundus

    IDs by its 4 tendons, one of which is about the length of the forearm

    Attachments:

    Lateral epicondyle of humerus

    Extensor expansion of medial 4 digits

    Action:Extends 5

    thdigit

    Nerve: posterior interosseous n., C7, C8,

    from the deep radial n.

    Extensor digiti minimi m.Its thin tendon is medial to the 4 tendons of

    extensor digitorum m.Attachments:

    Lateral epicondyle of the humerus

    Extensor expansion of the little finger

    Action:Extends the little finger

    The Austin Powers muscle, with his little

    pinky raised up

    Nerve: posterior interosseous n., C7, C8,from the deep radial n.

    Extensor carpi ulnaris m.Its tendon runs to the ulnar wrist, medial to

    extensor digiti minimi m.

    Attachments:Lateral epicondyle of humerus, and posterior

    border of ulnaBase of 5

    thmetacarpal

    Action:

    Extends and adducts the hand at wrist

    Nerve: posterior interosseous n., C7, C8,

    from the deep radial n.

    Outcropping musclesof the deep extensorcompartment

    The outcropping muscles pass over the tendonsof extensor carpi radialis longus and brevis mm.

    Abductor pollicis longus m.One of the outcropping muscles

    Start deep and emerge near the radial wrist

    Lies superior and lateral to extensor pollicis

    brevis m.

    Passes over the tendons of

    Extensor carpi radialis longus m.Extensor carpi radialis brevis m.

    Attachments:

    Posterior surface of ulna, radius, and

    interosseous membraneBase of 1

    stmetacarpal

    Action:Abducts and extends thumb

    Remember: abductors are always on the

    outside

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    Nerve: posterior interosseous n., C7, C8,from the deep radial n.

    Extensor pollicis brevis m.One of the outcropping muscles

    Lies inferior and medial to abductor pollicislongus m.

    Passes over the tendons of

    Extensor carpi radialis longus m.Extensor carpi radialis brevis m.

    Attachments:

    Posterior surface of radius and interosseous

    membraneBase of proximal phalanx of thumb

    Action:Extends thumb

    Nerve: posterior interosseous n., C7, C8,

    from the deep radial n.

    Extensor pollicis longus m.One of the outcropping muscles

    ID by its tendon seen running to the thumb

    Tendon lies medial to extensor carpi radialisbrevis m. and lateral to extensor indicis

    Attachments:

    Posterior surface of middle 1/3 of ulna andinterosseous membrane

    Base of distal phalanx of thumb

    Action:Extends thumb

    Nerve: posterior interosseous n., C7, C8,from the deep radial n.

    Extensor indicis m.

    ID by

    Tendon seen running to the index finger

    Most medial muscle belly of the deep

    extensors

    Tendon just medial to extensor pollicislongus m. at wrist

    Short muscle covered completely by the

    extensor digitorum m.Attachments:

    Posterior surface of ulna and interosseousmembrane

    Extensor expansion of index finger

    Action:

    Extends index finger

    Nerve: posterior interosseous n., C7, C8,from the deep radial n.

    Supinator m.

    Wraps around the proximal radius

    Attachments:Lateral epicondyle of the humerus, radial

    collateral and anular ligaments, supinatorfossa, and crest of the ulna

    Lateral, posterior, and anterior surfaces ofproximal 1/3 of radius

    Action:Supinates forearm = rotates radius to turn

    palm anteriorly

    Nerve: deep radial n., C5, C6Seen piercing through the supinator m.

    Hand

    Vessels of the hand

    Superficial palmar archcoming from the

    ulnar a.Anastomoses with the radial a., but it is

    primarily formed by the ulnar a.

    the arch is completed on the radialside by the superficial palmar

    branch of the radial artery

    The radial artery is the main sourceof blood to the deep palmar arterial

    arch, which is completed on the

    ulnar side by the deep branch of the

    ulnar artery.

    o runs deep in the hand, alongwith the deep ulnar nerve

    Nerve supply of the hand

    Motor supply to the handAll the muscle in the hand are innervated by

    the deep branch of ulnar n.EXECPT for

    LOAF muscles, which are innervated by the

    median n.

    Lateral 2 lumbricals

    Plus, the thenar eminence, by the recurrentbranch of median n.

    Opponens pollicis m.

    Abductor pollicis brevis m.Flexor pollicis brevis m.

    Digital branches of the ulnar n.

    The ulnar n. andulnar a.do NOT pass underthe flexor retinaculum

    They pass over the retinaculum through

    Guyons canal

    Cutaneous supply to the digitsMedial n.supplies cutaneous to the first 3 digits

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    Ulnar n.supplies cutaneous to the medial 1

    digits

    Flexor compartment of the hand

    Flexor retinaculum

    Tendon sheath that passes over the carpaltunnel

    Carpal tunnel

    If an instrument is placed passing through thetunnel, you would say carpal tunnel

    If a pin is in the tendon over the tunnel, youwould say flexor retinaculum

    Guyons tunnel

    Ulnar n. and a.pass through this tunnel

    Thenar eminence, big muscle pad at base ofthumb

    Nerve: recurrent branch of median n., C8,

    T1A branch of the median n.

    A motor nerve to the thenar eminence

    Seen crossing over flexor pollicis brevis m.

    toward abductor pollicis brevis m.

    If the recurrent branch is cut, the person losesthe ability to grasp, thus it is called themillion dollar nerve

    Consists of 3 muscles

    Abductor pollicis brevis m.

    Outermost of the 3 since it abducts

    Action: abducts thumb and helps oppose it

    Flexor pollicis brevis m.Medial to abductor pollicis brevis m.

    (closer to palm)

    Action: flexes thumb

    Opponens pollicis m.Under the other two

    Action: draws thumb

    Flexor pollicis longus m.

    Its tendon is seen running through the thenar

    eminence

    Hypothenar eminence, muscle pad at base oflittle fingerNerve: ulnar n.

    Consists of 3 muscles

    Abductor digiti minimi m.

    Outermost of the 3 since is abducts

    Action: abducts little finger

    Flexor digiti minimi brevis m.Medial to abductor digiti minimi m.

    Action: flexes little finger

    Opponens digiti minimi m.

    Under abductor digiti minimi m.

    Action: draws little finger toward thumb

    Flexor digitorum superficialis m.

    The most superficial tendons seen in the palmThese tendons run only to the middle phalanxwhere they splits, and the flexor digitorum

    profundus tendons passes between on theirway to the distal phalanx

    Flexor digitorum profundus m.Tendons that lie under the flexor digitorum

    superficialis

    These tendons give rise to the lumbricalsThese tendons run to the distal phalanx

    Lumbrical mm.Seen connecting the tendons of the flexor

    digitorum profundus in the palm

    Nerves:Lateral 2 lumbricals: median n.Medial 2 lumbricals: ulnar n.

    Palmaris brevis m.A tiny muscle that passes over proximal aspect

    of the hypothenar eminencewont be tested

    Adductor pollicis m.Has 2 heads

    Oblique head

    Transverse head

    Nerve: ulnar n., even though it on the lateralside of the palm

    Palmar interossei mm.Very deep, not easy to see

    Action: adductdigitsPAD Palmars are for ADductions

    Dorsal interossei mm.

    Seen from dorsum of hand, easier to see thanpalmar interossei

    1stdorsal interossei

    Broad superficial muscle between thumb andindex finger metacarpals

    Has 2 heads at wrist

    Pierced by radial a.between the 2 heads ofthe 1

    stdorsal interossei, near wrist

    Action: abductdigitsDAB Dorsals are for Abductions

    Superficial palmar arch

    Formed mainly by theulnar a.

    Forms an anastomosis with the radial a.

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    If asked where is this vessel is mainly from,you would say ulnar a.

    Deep palmar archYou wont see

    Formed mainly by the radial a.

    Digital branches of the median n.Branches in lateral aspect of palm near the

    base of the first 2 fingersMedial n. supplies cutaneous to the lateral 3 fingers

    Digital branches of the ulnar n.Branches in medial aspect of palm near the

    base of the little finger

    Ulnar n. supplies cutaneous to the medial 1 fingers

    Superficial radial n.Seen crossing over the anatomical snuff box

    Supplies only cutaneous to lateral dorsum ofthe hand

    It does NOT supply the nail beds, which are

    supplied by the medial and ulnar nn.

    Ulnar n.Seen medial to the proximal end of the

    hypothenar eminence

    Runs over the carpal tunnel, NOT through it

    Runs along with ulnar a.

    Cutaneous supply to last 1 fingers, plus their

    nail beds

    Median n.

    Runs through the carpal tunnel

    Cutaneous supply to first 3 fingers, plus

    their nail beds

    Flexor retinaculumLigament that forms the roof of the carpal

    tunnel

    Carpal tunnelHas 9 tendons passing through it

    4 from flexor digitorum superficialis m.

    4 from flexor digitorum profundus m.1 from flexor pollicis longus m.

    Ulnar and Radial Bursa also found

    Flexor pollicis longus is enclosed inits own synovial sheath in the

    carpal canal, called the radial

    bursa

    The tendons from flexor digitorumprofundus and flexor digitorum

    superficialis are all contained in a

    common synovial sheath, called the

    ulnar bursa

    Median n.is sandwiched in between thesetendons

    Carpal tunnel syndromeaffects the median

    n.

    Ulnar n.does NOT pass through the carpal

    tunnel, thus it is not affected in carpal tunnelsyndrome

    Extensor compartment of the hand

    Dorsal interossei mm.Seen on the dorsal aspect of the hand between

    the long metacarpal bones

    There are 4 dorsal interossei mm.

    1stdorsal interosseus m.

    Broad superficial muscle between themetacarpals of the thumb and index finger

    Has 2 heads at wrist

    Pierced by radial a.between the 2 heads of

    the 1stdorsal interossei, near wrist

    Action: abductdigitsDAB Dorsals are for Abductions

    In ID, you must say 1stdorsal interosseus

    musclenot just interosseus muscle

    Anatomical snuff boxLies between the tendons of

    Laterally: abductor pollicis longusand

    extensor pollicis brevisMedially: extensor pollicis longus

    Floor: scaphoid boneThe scaphoid bone is commonly fractured,

    and particularly prone to avascular

    necrosis

    Seen when thumb is fully extended (pointing

    up)

    Radial a.passes through the snuff box

    Superficial branch of the radial n.passes

    over the snuff boxDorsal expansion = Extensor expansion

    The shiny tendon through which the tendons

    of the fingers pass on the dorsal aspect of the

    fingers

    Lumbricalsand interosseiinsert into thesides of the dorsal expansion

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    Most commonly dislocated carpal bone is

    Lunate, most commonly fractured is

    scaphoid.

    Coracoclavicular ligament is very

    strong. When this ligament is torn, a

    patient will have a third degreeseparated shoulder

    Axis of rotation @ distal radio-ulnar

    joint is styloid process of ulna

    Most shoulder dislocations still occur

    in the anteroinferior direction, with

    the humeral head dislocating forwardand downward.

    A dislocated shoulder occurs when the

    humeral head slips out of the labrum;

    this often happens in the anterior

    direction

    A syndesmosis is a fibrous membrane

    or ligament that joins two bones. The

    connections between the shafts of the

    radius and ulna and the tibia and

    fibula are 2 classical examples of

    syndesmoses

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    Lower Limb

    Hip joint more stable than Shoulder joint

    because head of femur is more inside the

    acetabulum.Articulur cartilage is hyaline articulage here

    TMJ is synovial joint not covered by

    hyaline cartilage.Head of femur supplied by small branch ofobturator artery.

    Illifemoral Ligament: strongest of the body

    Prevents hyperextension of hip joint.Also called ligament of Bigelow

    Attached from ASIS to inter

    tronchanteric line.

    Prevents backward falling of the body

    Pubofemoral ligament: limits abduction and

    lateral rotationIlliopsoas bursa.

    Ischiofemoral ligament: weakest of all ligament.

    Limits medial rotation.

    It is the ligament that is most

    likely to be injured if the femur is

    dislocated posteriorlyIllipsoas attached to lesser trochanter

    Hip joint can be dislocated posterioly which can

    more likely injure sciatic nerve.(Slide 11 Dr. SamD)

    (Slide 12: D)Medial and lateral femoral circumflex arteriesprovide the anastomoses around neck of femur

    Medial circumflex femoralis the chief

    source.(Slide 16: D)

    Thigh

    External oblique aponeurosis

    Inguinal ligament, formed by the lower aspectof the external oblique aponeurosis

    Spermatic cord[testis removed]Cross-section of penis near pubic symphysisshows

    Corpus cavernosum

    Corpus spongiosum, with spongy urethra

    Deep fasciaA stocking-like covering over the entire lower

    limb

    Separates muscles from each other and investsthem

    Prevents bulging of the muscles duringcontraction

    Makes the muscles more efficient in pumpingblood toward the heart

    Divided into 2 regions

    Fascia lata, the deep fascia of the thigh

    Crural fascia, the deep fascia of the leg

    Saphenous ring (opening)A deficiency in the deep fascia lata inferior to

    the medial part of the inguinal ligament

    Great saphenous v.passes through the ring to

    enter the femoral v.

    Iliotibial tractThe conjoint aponeurosis of the

    Gluteus maximus m.

    Tensor fascia lata m.

    Extends from the iliac tubercleto the lateral

    condyle of the tibia

    Femoral triangleBounded by

    Base of triangle, superior aspect: inguinal

    ligament, which ends medially as the lacuna

    ligamentMedial: adductor longus m.

    Lateral: sartorius m.

    Floor: iliopsoas m.laterally, and pectineus m.

    mediallyApex: the beginning of the adductor canal, at

    the junction of sartorius and adductor longus

    mm.In order from lateral to medial

    N Femoral n.

    A Femoral a.

    V Femoral v.

    E Empty space

    L Lacuna ligament or Lymph nodes

    Femoral n., L2, L3, L4Breaks up very quickly into a series of nervebranches

    If all its branches were tagged as one group,

    you would say its the femoral nerveOutside of Femoral sheath

    Saphenous n.is one of the many branches ofthe femoral n.

    Supplies cutaneous innervation to the medial

    aspect of the foot

    It can be IDs at 2 pointsa. As it enters the adductor canalat theapex of the triangle along with the femoral

    a. and v.

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    NOTE: the saphenous n. does NOT exit

    the adductor hiatus

    b. As it passes anterior to the medialmalleolus, accompanied by the great

    saphenous v.

    Femoral a.A continuation of the external iliac a., which

    changes its name to the femoral a. once it

    passes under the inguinal ligamentRuns with the femoral v.

    Enters the adductor canal along with thefemoral v. and saphenous n.

    Profunda femoris a. = Deep artery of thighA large branch off the femoral a., soon after it

    passes under the inguinal ligament

    Parallels the course of the femoral a., but goesdeeper

    The main blood supply to the thigh

    Also supplies the Hamstring compartment Branches are known as arterial

    perforators.

    The femoral a. itself contributes very little

    direct blood supply of the thigh. It continueson as the popliteal a. which supplies the leg

    Profunda femoris a. divides into 2 branches

    Medial circumflex femoral a.The most important artery of the cruciate

    anastomosis, which supplies the head and

    neck of the femurLateral circumflex femoral a.

    descending branch of thelateral circumflex femoral

    artery anastamoses with both

    the descending genicular

    branch of the femoral artery as

    well as the lateral superior

    genicular branch of the

    popliteal artery

    o These connectionsprovide collateralcirculation to the knee

    and leg

    Cruciate anastomosisForms a cross

    It is the blood supply to the head and neck ofthe femur

    Superior part of the cross: a branch of the

    inferior gluteal a.

    Lateral part of the cross: lateral circumflex

    femoral a.

    Medial part of the cross: medial circumflex

    femoral a.

    Inferior part of the cross: 1stperforating

    branch of the profunda femoris a.

    Femoral v.Runs with the femoral a.

    You can tell that its the femoral v. (and not

    the great saphenous v. because the femoral v.is deeper and passed through the adductor

    canal along with the femoral a. and saphenous

    n.

    Great saphenous v.A superficial vein, thus it does NOT enter the

    adductor canal

    Accompanied by the saphenous n.,from theknee to the foot

    PathwayOriginates from the medial aspect of the

    dorsal venous archPasses anterior to the medial malleolus

    Passes posterior to the medial condyle of the

    femurComes through the saphenous ringin the

    fascia lataEmpties into the femoral v.

    Empty space

    Allows for veins to expand so more blood can

    return to heart.Has the femoral ring and the femoral canal

    A potential site for femoral hernias, whereparietal peritoneum comes through

    Hernias Tend to be U- shaped in

    natureMore common in women

    Pieces of bowel can come down with the

    transversalis fascia pushing through.

    Pubic tubercle is landmark

    Any hearnia above it is called Inguinal

    Any hernia below it is called femoral

    They tend to be strangulated for 2 reasons

    There is a sharp boundary on the

    lacunar ligament

    Modification of inguinal ligament

    This can cause strangulation of

    femoral hernia which can result in

    necrosis of intestine.

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    Accessory obturator artery: present

    sometimes which can cause bleeding

    whilecutting the lacunar ligament.Branch of inferior epigastric

    artery.

    The saphenous ring where the great

    saphenous vein enters, where it can be

    caught up

    Perforating veins are first ones to getvalve failures.

    Lesser (Small) saphenous vein more

    likely to be varicosed on calf muscles.

    Great saphenous more like to varicose on

    the medial side of thigh.

    An obturator hernia is a protrusion of a

    loop of bowel through the obturator

    canal.

    with a loop of ilium passinginferiorly, posterior to thesuperior pubic ramus

    Lacuna ligamentHas a sharp lateral edge that can cause

    strangulation of a femoral herniaWont have to ID, but know about it

    Adductor canal = Hunters canalRuns from the apex of the femoral triangle to

    the adductor hiatusdistal to the attachment of

    the adductor magnus m. on the adductor

    tubercle of the femur

    Between the vastus medialis m. and theadductor muscles, and converted into a canalby the overlying sartorius m.

    Has the following that passes through it

    Femoral a.

    Femoral v.

    Saphenous n.

    When the femoral a. and v. exit through theadductor hiatus, they change their names tothe popliteal a. and v.Note: the saphenous n., which entered the

    adductor canal, does NOT exit the adductorhiatus

    Anterior Thigh

    Femoral n., L2, L3, L4Innervates the

    Quadriceps femoris mm.

    Sartorius m.

    Pectineus m., which is also innervated bythe obturator n.

    Branches to form the saphenous n.Supplies cutaneous innervation to the medial

    aspect of the foot

    It can be IDs at 2 pointsa. As it enters the adductor canalat the

    apex of the triangle along with the femoral

    a. and v.NOTE: the saphenous n. does NOT exit

    the adductor hiatusb. As it passes anterior to the medial

    malleolus, accompanied by the great

    saphenous v.

    Sartorius m.

    Attachments:

    ASIS, then crosses anterior thigh

    Pes anserinus, on the medial aspect of thetibia

    Actions: puts you in a tailors position, a

    cross-legged positionYou need to know the difference between its

    action at the hip and its action at the knee

    If you asked for the sartorius action at the

    hip, you would say

    Laterally rotates hip

    Flexes hip

    Abducts hip

    If you asked for the sartorius action at theknee, you would say

    Medially rotates knee

    Flexes knee Sartorius is the roof of the

    adductor canal.

    The sartorius m. divides the muscles of the

    anterior compartment of the thigh into 2groups

    1. Anterior group

    Femoral n.innervates everything in the

    anterior thigh

    2. Abductor groupObturator n.innervates everything in the

    adductor region, with 2exceptionsPectineus m.is innervated by 2 nerves

    Obturator n.

    Femoral n.

    Adductor magnus m.has 2 portions,each with a different nerve

    Tibial n.innervates the hamstring

    portion

    Obturator n.innervates the adductor

    portion

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    Quadricepsfemoris mm.consist of 4 muscles

    1. Rectus femoris m.You can see that its the rectus femoris

    because it is straight

    AttachmentsAIIS, anterior inferior iliac spine

    Rectus femoris m. is the only quadriceps

    muscle that crosses the hip, thus its the

    only quadriceps that can also flex the hip2. Vastus lateralis m.

    3. Vastus intermedius m.Lies under rectus femoris m.

    4. Vastus medialis m.

    Quadriceps tendonis the common tendon ofall 4 muscles at the knee

    Attaches to the base (superior aspect) of thepatella ; becomes the patellar tendon.

    At the apex (inferior aspect) of the patella it

    continues as the patellar ligamentwhichattaches to the tibial tuberositynot

    quadriceps tendon

    The quadriceps tendon/patellar ligamentinserts into the tibial tuberosity

    Main action: Extensionat the knee joint

    Rectus femoris m.also crosses the hip, thus

    it can also flexthe hip

    Nerve: femoral n., L2, L3, L4

    Knee Jerk: tests the value of L3 L4

    Iliopsoas m.

    Lies just medial to the sartorius originFrom this perspective, only small part of its

    most inferior portion is visible as it inserts intothe lesser trochanter of the femur

    Attachments:

    Psoas major: sides, discs and transverseprocesses of T12-L5

    Psoas minor: sides and discs of T12-L1

    Iliacus m.: iliac crest and fossa

    Insertion: lesser trochanter of the femurThe iliopsoas m. is the only muscle that

    attaches at the lesser trochanter of thefemur

    Nerve: L1, L2, L3

    Medial Thigh

    Action: adducts thigh

    Nerve:obturator n

    Travels thru obturator foramen

    accompanied by obturator artery

    Can be compressed in females by

    ovarian enlargement (Poly cystic ovarian

    disease)

    Pain in medial side of legSeen under the adductor longus m.

    Innervates all of the adductor groupwith 2

    EXCEPTIONS

    Pectineusm. is also receives innervated by

    the femoral n.

    The hamstring portion of adductor magnusm.is innervated by the tibial n.

    Adductor longus m.Most superficial of the adductor muscles, just

    lateral to the gracilis m.

    Most commonly affected muscle in groin

    strain

    The femoral artery is superficial to

    adductor longus, while the deep femoralartery is deep to adductor longus.

    Pectineus m.

    Lies just lateral to adductor longus m.

    Lies just medial to the femoral vein, formingthe medial floor of the femoral triangle

    Has dual innervation

    Femoral n.

    Obturator n.

    If asked What is the nerve supply topectineus muscle?, you must write both

    nerves femoral nerve and obturator nerveAdductor brevis m.

    Lies under adductor longus m.

    Obturator n.passes anterior to adductorbrevis m. and sends a posterior branch through

    the muscle

    Obturator externus m.Lies under the pectineus m.

    Its fibers run transversely, left to right

    Adductor magnus m.A huge muscle

    The upper aspect lies under adductor brevis m.

    Seen more clearly from the posterior view

    Nerves:Has 2 portions, each with a different nerve

    Tibial n.innervates the hamstring portion

    Obturator n.innervates the adductorportion

    Forms the Adductor Hiatus

    Gracilis m.

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    The most medial muscle of the thigh

    Runs in a straight courseAttachments:

    Pubis

    Pes anserinuson the medial aspect of the

    tibiaAction:

    Crosses both the hip and knee joints, thus it

    Flexes the kneeSlightly adducts the thigh

    Innervated by Obturator nerve

    Gluteal Region

    Tensor fascia lata m.Lies within the iliotibial tract at the superior

    end

    Considered to be part of the gluteal regionbased on its innervation, but it is seen in the

    anterior thigh

    Nerve: superior gluteal n.Tensor fascia lata isNOT supplied by the

    femoral n.even though it seems to be part of

    the anterior region

    In fact it is part of the gluteal region, not theanterior thigh region

    Gluteus maximus m.

    Main action:forcedextension, NOT ordinaryextension as when walking

    Extends the thigh when rising from sitting or

    climbing

    Attachments:2/3into the iliotibial tract

    1/3into the gluteal tuberosityof the femur

    Considered part of the medial group due to itsother actions:

    Laterally rotates thigh

    Extension of hip Joint: Major action!!

    Nerve: inferior gluteal n (L5, S1, S2)A long nerve that exits the pelvis below thepiriformis m. through the greater sciatic

    foramen to reach the ventral aspect of the

    gluteus maximus m.

    Dont give any intramuscular injection until

    6yrs of age coz this muscle doesnt develop

    until 6yrs of age.

    Injection giving insuperiolateral quadrant.

    o Nerve injured can besuperior gluteal

    nerve.

    Lateral group of muscles in the gluteal region

    The actions of these muscles areChief stabilizers of the hip

    Medial hip rotators

    Abductors of the thigh

    1. Gluteus medius m.A fan-shaped muscle that lies just superior to

    the piriformis m.

    Attachment: greater trochanter

    Nerve and blood: superior gluteal n. and a.,which lies between the gluteus medius m. and

    gluteus minimus m.The superior gluteal n. and a. exit the pelvis

    above the piriformis m. through the greater

    sciatic foramen

    2. Gluteus minimus m.

    Lies under the gluteus medius m., also just

    superior to the piriformis m.

    Attachment: greater trochanter

    Nerve and blood: superior gluteal n. and a.,which lies between the gluteus medius m. and

    gluteus minimus m.

    Main action of gluteus medius and minimus:The chief stabilizers of the hip joint

    If asked what is the main action of gluteusmedius and minimus?, you would say they

    are the chief stabilizers of the hip joint

    They are responsible for holding the weight

    over the hip joint, keeping the hip jointslevel when a leg is lifted off the ground

    Other actions of gluteus medius and minimus:Medially rotates thigh, these are the medial

    rotators of the thigh

    Abducts thigh

    Superior gluteal n. innervates

    Gluteus medius m.

    Gluteus minimus m.

    Tensor fascia lata m.

    If the superior gluteal n.is injured, we losethe 2 muscles that are the primary stabilizes of

    the hip joint, causing a condition called

    Trendelenburg signInjury to the superior gluteal n. is very

    commonly seen in poliomyelitis

    To test, stand behind patient, place your handson their hips, eye level with their pelvis, thenasked the patient to stand on one leg.

    If the unsupported pelvis goes upward, thats

    normal.

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    If the unsupported pelvis descends, thats a(+) Trendelenburg sign. It indicates a weakgluteus medius m. on the supported side

    Patient will fall toward the opposite side of

    the lesion

    Medial group of muscles in the gluteal region

    The actions of these muscles are

    Lateral hip rotatorsAbductors of the thigh

    1. Piriformis m.Nerve: nerve to piriformis

    A key muscle to the gluteal region

    Anything that exits above the piriformis is

    the superior gluteal n., a., v.

    Everything else exits below the piriformis,

    including

    Inferior gluteal n., a., v.

    Sciatic n., L4, L5, S1, S2, S3

    Internal pudendal a. and v.Pudendal n.

    2. Superior gemellus m.Lies just inferior to the piriformis m.

    Nerve: nerve to obturator internus

    3. Tendon of obturator internus m.Lies just inferior to the superior gemellus m.

    Nerve: nerve to obturator internus, which

    also supplies superior gemellus m., above it

    Remember: obturator internus m. is the onlymuscle that passes through the lesser sciatic

    foramen

    If asked whichmuscle passes through thelesser sciatic foramen?, you would say

    obturator internus muscle

    4. Inferior gemellus m.Lies just inferior to the tendon of obturator

    internus m.Nerve: nerve to quadratus femoris

    5. Quadratus femoris m.Lies just inferior to the inferior gemellus m.

    Nerve: nerve to quadratus femoris, whichalso supplies inferior gemellus m.

    NOTE: The gemellus muscles receive theinnervation of the muscle below them

    Sacrotuberous ligament

    Sacrospinous ligament, deep to thesacrotuberous ligament

    Exiting between these 2 ligaments are the

    Internal pudendal a. and v., blood supply to

    the perineum

    Pudendal n., S2, S3, S4, nerve supply to the

    perineum

    These 3 exit via the greater sciatic foramenand reenter via the lesser sciatic foramen,traveling within Alcocks canal

    So if you see vessels or a nerve passingbelow the sacrotuberous ligament, you know

    they are the internal pudendal a. and v., and

    pudendal n.

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    Posterior Thigh

    Sciatic n.The largest nerve in the body

    Innervates

    Posterior thigh musclesEverything from the knee down

    Runs down the posterior leg

    Formed from by the joining ofLumbosacral trunk, L4, L5

    S1, S2, S3

    Composed of 2 nerves which divide into the

    Tibial n., the larger of the 2, and more

    medial

    Common peroneal n.

    It important to orient yourself so you can tell

    medial from lateral, since the nerve runningmedially has to be the tibial n., and the nerve

    running laterally has to be the common

    peroneal n.

    Tibial n.Runs more medially down the thigh to thecenter of the popliteal fossa

    Innervates 2 main regions1. All the posterior thigh muscles, such as the

    hamstrings, EXCEPT

    Short head of biceps femoris m., which is

    innervated by the common peroneal n.

    Adductor portion of adductor magnus

    m., which is innervated by the obturator n.2. All the posterior compartment of theleg, which are the plantar flexors

    After passing posterior to the medialmalleolus, the tibial n. divides into

    Lateral plantar n.

    Medial plantar n.

    If the tibial n. is injured, the person cant

    plantar flex the ankle, which means they cant

    lift their heel, and the heel will drag along the

    ground, a condition called a shuffling gait

    Common peroneal n.Runs down the thigh to the lateral aspect of the

    knee

    Wraps around the neck of the fibula, and at

    this point is very superficial and, thus, easily

    prone to injury

    Innervates1. Only one musclein the posterior thigh

    short head of biceps femoris m.

    2. All the muscles of anterior and lateral

    compartments of leg

    In the leg the common peroneal n. divides into2 nerves

    Deep peroneal n.,innervates the anterior

    compartment of legDorsiflexes the ankle

    Inverts the foot

    Superficial peroneal n.,innervates thelateral compartment of leg

    Everts the foot

    Weakly plantar flexes the ankle

    If the neck of the fibula is tagged, and you areasked, What happens if the bone is fractured

    at this point, you would say the commonperoneal nerve is damaged

    If the common peroneal n. is injured, theperson loses their deep and superficial

    peroneal nn., thus losing both the anterior and

    lateral compartments. The result is that theycant dorsiflex the ankle, cant extend the toes,

    and cant evert the foot, which means they

    cant lift the foot or toes, and their toes will

    drag along the ground, a condition called foot

    drop

    To compensate and avoid dragging their toes,the person develops a gait in which they lift

    their leg very high

    Foot drop = common peroneal n. damage =

    fibular fractureHamstrings

    To qualify as a true hamstring muscle, the

    muscle must

    a. Attach at the ischial tuberosity

    b. Cross both the hip joint and knee joint, thusthey

    Extend the thigh

    Flex the knee

    Nerve: tibial n.

    The hamstrings consist of 3 muscles

    1. Long head of the biceps femoris m.Most lateral muscle of the 3 hamstring

    muscles

    Attachments:Ischial tuberosityHead of the fibula, on lateral knee

    Note: the short head of the biceps femoris m.is NOT a true hamstring

    To ID, you must say long head or shorthead of the biceps femoris muscle

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    2. Semitendinosus m.Attachments:

    At the ischial tuberosity, it is just medial to

    the biceps femoris m.

    Pes anserinusat the medial tibia

    To ID, notice that it half muscle and halftendon

    3. Semimembranosus m.

    Attachments:Ischial tuberosity

    Medial tibia, superior to the pes anserinus,

    NOT in it

    Lies immediately under semitendinosus m.

    To ID, notice that is half membranous andhalf muscle

    Short head of the biceps femoris m.

    Is NOT a true hamstring muscle since itDoes not attach at the ischial tuberosity

    Does not cross the hip joint

    Nerve: common peroneal n.It is important in that it is the only muscle in

    the posterior thigh that receives the commonperoneal n.

    The true hamstrings are innervated by thetibial n.

    Adductor magnus m.Is part of the adductor region, NOT posterior

    thigh, however, it can be seen most clearly

    from the posterior aspect

    It has 2 portionsAdductor portion

    More superior portion, with fibers running

    toward the adductors

    Attachments:

    Inferior ramus of the pubis

    Gluteal tuberosity and linea aspera

    Nerve: obturator n.

    Hamstring portionMore inferior portion, with aprominent

    tendon

    Attachments:Ischial tuberosity

    Adductor tubercle of the femur

    Nerve: tibial n.

    Adductor hiatus

    Formed at the junction of the adductor portionand hamstring portion of the adductor magnus

    m.

    The opening is just superior to the adductortubercle of the femur

    You need to be able to differentiate betweenartery, vein, and nerve at the apex of thefemoral triangle, and at the adductor hiatus

    At the adductor hiatus, the popliteal v.is themost superficialvessel, and the popliteal a.

    lies beneath the vein

    At the apex of the femoral triangle, the

    femoral a.is the most superficial, and the

    femoral v.lies beneath the artery, which isvery unusual in the body

    After the femoral a. and v.pass through theadductor canal, they exit the adductor hiatus as

    the popliteal a. and v., with the popliteal v. as

    the most superficial vessel

    Knee joint

    Orient yourself to find the 3 bones of the kneejoint

    Femur

    TibiaFibula, located on the lateral aspect

    Femur

    Lateral condyleIDs by locating the fibula below it

    Medial condyle

    Tibia

    Lateral condyleIDs by locating the fibula beside it

    Medial condyle

    Tibial plateau

    On the anterior aspect of the flexed knee

    Lateral meniscus, under the lateral condyle

    Medial meniscus, under the medial condyleThe medial meniscus is more often injuredbecause it is NOT mobile since it is attached to

    the medial collateral ligament

    The menisci are made out of fibrocartilage

    Anterior cruciate ligament, ACLAttachmentsthese are tested in the USMLE

    From anterior surface of the tibial plateau

    To the medial aspect of the lateral condyleIf the anterior cruciate ligament were tagged,

    and it asked what action does this ligament

    help to prevent?, you would sayhyperextensionof the knee joint

    The ACL prevents the tibia from slidinganteriorly forward

    Prevents the femur fromsliding backwards in

    relation to tibia.

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    Not attached to anymenisci.

    The anterior cruciate ligament is 4 times more

    likely to be injured than the posterior cruciate

    ligament

    To test, do an anterior draw sign

    On the lateral aspects of the knee, the collateral

    ligaments prevent any excessive adductive orabduction of the knee

    Medial collateral ligament, MCL = Tibial

    collateral ligament

    Attaches to the medial meniscus, which in

    turn attaches to the anterior cruciate

    ligament, producing the unhappy triad

    A lateral blow to the knee, when the knee isflexed and the foot is firmly planted on the

    ground, can tear the medial meniscus and push

    it medially and tear the anterior cruciate

    ligament, which in turn can tear the medialmeniscusthus the unhappy triada very

    common sports injury

    Lateral collateral ligament, LCL = Fibular

    collateral ligament

    The tendon of thepopliteus m.passesunderneath the lateral collateral ligament,

    which separates the lateral collateral ligamentfrom the lateral meniscus

    Thus, the lateral collateral ligament is NOT

    attached to the lateral meniscus, thus leaving

    the lateral meniscus much more mobile and farless prone to injury than the medial meniscus.

    An injury to the lateral collateral ligament

    does not effect the lateral meniscus

    On the posterior aspect of the extended knee

    Posterior cruciate ligament, PCLAttachments

    From posterior surface of the tibia

    To the medial aspect of the medial condyle

    If the posterior cruciate ligament were tagged,

    and it asked what action does this ligamenthelp to prevent?, you would sayhyperflexionof the knee joint

    The PCL prevents the tibia from slidingposteriorly backward

    Prevents the femur fromsliding forward on the tibia

    Posterior meniscofemoral ligamentPasses posterior to the posterior cruciate

    ligament

    Attaches on the lateral aspect of the medialcondyle of the femurwith the posteriorcruciate ligament, but then attaches to the

    posterior aspect of the lateral meniscus

    Give reinforcement to the posterior aspect ofthe knee joint

    Leg

    Orient yourself by looking for theTibia and the big toe, which are on the medial

    sideFibula and little toe, which are on the lateral

    side

    Anterior

    compartment

    Lateral

    compartment

    Posterior

    compartment

    Deep peronealn.

    Superficialperoneal n.

    Tibial n.

    Dorsiflexes

    ankle

    Extends toes

    Inverts foot

    Everts foot

    Plantar

    flexion

    Plantar flexes

    ankle

    Flexes toes

    Injury to the common peronealn. = foot drop

    Injury to thetibial n. =

    shuffling gait

    Injury to the sciatic n. effects all the above =

    peculiar gait, person has great difficulty

    walking because most of the work is done at thehip instead of thigh and leg

    Unlike the hip and thigh, you dont need toknow the attachments of the muscles of the leg,

    EXCEPT for those that are unusual such as

    Tibialis anterior m., which attaches at themedial base of the 1

    stmetatarsal under the

    medial aspect of the foot

    Inversion will not be lost in footdrop coz Tibialis posterior still

    does inversion.

    Peroneus longus m., which attaches at thelateral base of the 1

    stmetatarsal under the

    medial aspect of the footPeroneus brevis m., which attaches at thebase of the 5

    thmetatarsal

    Its best to think of the muscles of the leg with

    respect to their compartment, which associated

    the muscles with their action and nerve supply

    When you ID a muscle of the leg, be sure tofollow its tendon to see where it attaches

    Anterior Leg

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    Medial aspect of the tibia has no muscleattachments, a good orientation point whenviewing the anterior compartment

    Responsible forDorsiflexion of the ankle via anterior tibialis

    m.

    Extension of the toes

    Inversion of the foot via tibialis anterior m.,turning soles inward

    Deep peroneal n.a. As a motor nerve, it innervates

    All of the muscles of the anterior

    compartment

    2 muscles of the dorsum of the foot

    Extensor hallucis brevis m.

    Extensor digitorum brevis m.

    Best seen just with anterior tibial a. and v.,just superior to the ankle between the

    tendons of tibialis anterior and extensorhallucis longus

    b. As a cutaneous nerve, it innervates the skinof 1

    stdorsal web space

    Best seen in the 1stweb space between the

    big toe and 2nd

    toe

    If a pin were placed in the 1stweb asking

    what is the cutaneous nerve supply to this

    area?, you would say deep peroneal n.

    Anterior tibial a. and v.Accompany the deep peroneal n. from the

    knee to the dorsum of the footBest seen with the deep peroneal n. just

    superior to the ankle, between the tendons oftibialis anterior and extensor hallucis longus

    The artery becomes the dorsalis pedis a.afterpassing the ankle joint,

    Dorsalis pedis a.

    Runs between the 1stand 2

    ndmetatarsals,

    pierces through the 1stdorsal interosseous,

    and joins the plantar arch

    Its where the pedal pulseis taken

    The muscles of the anterior compartment, frommost medial to lateral, are:

    Tibialis anterior m.Attachments:

    Lateral condyle of the tibia

    Base of the 1stmetatarsalunder the medial

    foot

    IDd as the most medial tendon at theanterior ankle, passing anterior to the medialmalleolus, then under the medial foot

    Action:Invert the foot, due to its attachment at the

    base of the 1stmetatarsal under the medial

    foot

    Dorsiflexes foot

    Extends the toes

    Extensor hallucis longus m.ID by

    Its muscle portion seen just lateral to tibialis

    anterior near the ankle

    Its tendon running to the big toe

    Action: extends big toe

    Extensor digitorum longus m.ID by

    Its muscle portion runs the length of the

    anterior leg, the most lateral tendon at theanterior ankle

    Its division into 4 different tendons

    Action: extends all toes, except big toe

    Peroneus tertius m.wont be tested

    A small part of the extensor digitorum

    longusthat is sometimes named as a separatemuscle

    Its tendon attaches near the little toe

    Lateral Leg

    Responsible forEversion of the foot, turning soles outwardWeak plantar flexion of the ankle

    Superficial peroneal n.

    As a motor nerve, it innervates the muscles ofthe lateral compartment

    Best seen as it pierces through the extensordigitorum longus m.,

    just medial to the peroneus mm.

    As a cutaneous nerve, it innervates the skinover the entire dorsum of the foot

    EXCEPTthe skin of 1st

    dorsal web space,which is supplied by the deep peroneal n.

    Seen branching over the dorsum of the foot

    Peroneus longus m.More super


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