Anterior Anterior abdominal wallabdominal wall

Layers of Anterior Layers of Anterior Abdominal WallAbdominal Wall

In In human anatomyhuman anatomy, the layers of the abdominal wall , the layers of the abdominal wall are (from superficial to deep):are (from superficial to deep):

Skin Skin Fascia Fascia

Camper's fascia - fatty superficial layer. Camper's fascia - fatty superficial layer. Scarpa's fascia - deep fibrous layer. Scarpa's fascia - deep fibrous layer.

MuscleMuscle-Rectus abdominis -Rectus abdominis -External oblique muscle -External oblique muscle -Internal oblique muscle -Internal oblique muscle -Transverse abdominal muscle-Transverse abdominal musclePyramidalis musclePyramidalis muscleCremasteric Cremasteric

Fascia transversalis Fascia transversalis Parital Peritoneum Parital Peritoneum

Fascia of Ant. Fascia of Ant. Abdominal WallAbdominal Wall

1- there is no deep fascia 1- there is no deep fascia

2-the superficial fascia is formed of a 2-the superficial fascia is formed of a single layer above the ambilicus , but single layer above the ambilicus , but below the ambilicus below the ambilicus it differentiated it differentiated into 2 layers:into 2 layers:

a- superficial fatty layer a- superficial fatty layer (Camper’s fascia)(Camper’s fascia)

- contains variable amount of fat .- contains variable amount of fat .

b- deep membranes layer b- deep membranes layer (Scarpa’s fascia)(Scarpa’s fascia)

-continuous with the superficil perineal fascia -continuous with the superficil perineal fascia (colle’s (colle’s

fascia)fascia)

Linea AlbaLinea Alba

An extensive aponeurosis An extensive aponeurosis which extend from the which extend from the xiphoid process to the xiphoid process to the symphsis pubissymphsis pubis. .

Linea Semilunaris

the lateral margin of rectus abdominis is marked by a line on the anterior abdominal wall called linea semilunaris

Muscles of the anterior Muscles of the anterior abdominal wallabdominal wall

Classified into 2 groups:

1- paramedian muscles

- Rectus abdominis muscle

- Pyramidalis muscle

2 -anterolateral flat muscles

- external abdominal oblique m.

- internal abdominal oblique m.

- transversus abdominis m.

Abdominal external oblique Abdominal external oblique musclemuscle

the largest and the largest and the most the most superficial of the superficial of the three flat three flat muscles of the muscles of the lateral anterior lateral anterior abdomen.abdomen.

OriginOrigin: : lower 8 ribs (outer surface)lower 8 ribs (outer surface)

Direction of the fibersDirection of the fibers: : downwards , forwards & downwards , forwards &

medialymedialy

InsertionInsertion: : - - iliac crest ( anterior half of iliac crest ( anterior half of

the outer lip)the outer lip)- - anterior superior iliac spineanterior superior iliac spine

- - pubic tuberclepubic tubercle- - pubic crestpubic crest

- - linea albalinea alba………………………….

Inguinal ligamentInguinal ligament

--It is the infolded It is the infolded lower border of lower border of the external the external oblique moblique m . .

--The inguinal The inguinal ligament runs ligament runs from the anterior from the anterior superior iliac superior iliac spine to the pubic spine to the pubic tubercletubercle..

Abdominal internal Abdominal internal oblique muscleoblique muscle

Origin :Origin : 1- iliac crest (ant. 2/3 of its 1- iliac crest (ant. 2/3 of its

intermediate line)intermediate line) 2- inguinal ligament 2- inguinal ligament ( lateral 2/3 of its inner surface).( lateral 2/3 of its inner surface). 3- lumbar fascia .3- lumbar fascia .

Direction of the fibers :Direction of the fibers : upwards , forwards and medialy upwards , forwards and medialy

Insertion :Insertion : 1- linea alba 1- linea alba 2- lower 4 or 5 ribs 2- lower 4 or 5 ribs 3- the lower fibers forms an arched 3- the lower fibers forms an arched

fibers called the fibers called the conjoint tendon.conjoint tendon.

Conjoint tendonConjoint tendon

--Formed by the lower arched fibers of both Formed by the lower arched fibers of both internal oblique and transversus abdominis internal oblique and transversus abdominis muscles where the fiberous pass directly muscles where the fiberous pass directly from origin to insertionfrom origin to insertion

--FunctionFunction: : The contraction of the conjoint tenden leads The contraction of the conjoint tenden leads

to closure of the inguinal canalto closure of the inguinal canal ((shutter mechanismshutter mechanism) )

--So , it prevent passage of intestine through So , it prevent passage of intestine through the canal (Indirect inguinal hernia)the canal (Indirect inguinal hernia). .

Transversus abdominis Transversus abdominis musclemuscle

OriginOrigin: : --the lateral third of the inner surface of the lateral third of the inner surface of

inguinal ligamentinguinal ligament --anterior 2/3 of the medial lip of the iliac anterior 2/3 of the medial lip of the iliac

crestcrest--the inner surfaces of the cartilages of the the inner surfaces of the cartilages of the

lower 8 ribslower 8 ribs--the thoracolumbarl fasciathe thoracolumbarl fascia..

Direction of the fibersDirection of the fibers: : - - horizontalyhorizontaly. .

InsertionInsertion:: a- linea albaa- linea alba

b-the lower fibers form an arched fibers b-the lower fibers form an arched fibers together with the lower fibers of together with the lower fibers of internal oblique muscle (conjoint internal oblique muscle (conjoint

tendon)tendon)

Site : it lies in the middle part of the abdominal muscle layer inside the tendinous sheath called rectus sheath.Origin : symphysis pupis and pubic crest.Insetion:5th, 6th & 7th costal cartilages--The muscle is divided by 3 tendinous intersections as follows:-These tendentious intersections are present on the anterior surface of the muscle and indicate that the muscle arises from different myotomes .

Rectus abdominus m.

Action: - flexion of the

trunk. Surface anatomy:

the lateral margin of rectus abdominis is marked by aline on the anterior abdominal wall called linea

semilunaris.

Cremastric muscleCremastric muscle:: It is formed by loops of It is formed by loops of

muscle fibres from the lower muscle fibres from the lower part of the internal obliquepart of the internal oblique

it extends down through the it extends down through the spermatic cord & return spermatic cord & return behind it to be attached to the behind it to be attached to the pupic tuberclepupic tubercle

its n. supply is the genital its n. supply is the genital branch of the genitofemoral branch of the genitofemoral n.n.

action:action: elevation of testis upwards elevation of testis upwards

in the cold weather.in the cold weather. Cremastric reflex:Cremastric reflex: Scratching of the upper & Scratching of the upper &

medial parts of the thigh (L1) medial parts of the thigh (L1) leads to elevation of the leads to elevation of the testis.testis.

Pyramidalis musclePyramidalis muscle: : origin :origin : pubic crest and symphysis pubic crest and symphysis

pubis pubis

insertioninsertion : : into the lower part of the linea into the lower part of the linea

alba alba

nerve supply :nerve supply : subcostal nerve subcostal nerve action :action : it stretches the linea alba it stretches the linea alba

Action of the anterior Action of the anterior abdominal wall musclesabdominal wall muscles

11--supportsupport the viscera and keep them in their position the viscera and keep them in their position 22--contractcontract to increase the intra-abdominal pressure to increase the intra-abdominal pressure

during urination and defection (mainly the during urination and defection (mainly the trunsversus abdominis)trunsversus abdominis)..

33--expiratory actionexpiratory action: : - - the abdominal muscles contract during expiration the abdominal muscles contract during expiration

and relax during inspiraionand relax during inspiraion. . 44--movement of the trunkmovement of the trunk: :

a-contraction of rectus abdominis muscle a-contraction of rectus abdominis muscle ……..forward flexion……..forward flexion..

b-contraction of one side of the oblique muscles b-contraction of one side of the oblique muscles ……….lateral flexion……….lateral flexion. .

c. combined action of external oblique with the c. combined action of external oblique with the oppisite internal oblique ……rotation of the oppisite internal oblique ……rotation of the trunktrunk. .

55 - -elevation of the testiselevation of the testis ………..by the cremastric m ………..by the cremastric m. .

Inguinal canalInguinal canal

Definition:Definition: It is an oblique inter-It is an oblique inter-

muscular canal (4cm) muscular canal (4cm) above the medial part above the medial part of the inguinal of the inguinal ligament.ligament.

Openings:Openings:

--it starts at the it starts at the deep inguinal ring deep inguinal ring and ends at the and ends at the superfascial superfascial inguinal ring.inguinal ring.

a-Superfascial Inguinal a-Superfascial Inguinal RingRing

SiteSite:: it is a triangular or inverted it is a triangular or inverted

V shaped opening in the V shaped opening in the external oblique external oblique aponeurosisaponeurosis..

its margins give theits margins give the externalexternal spermatic fascia spermatic fascia to cover the spermatic cordto cover the spermatic cord..

Surface anatomySurface anatomy::It lies just above the pupic tubercleIt lies just above the pupic tubercle..

Structures passing Structures passing through itthrough it::

--illio-inguinal nerveillio-inguinal nerve..--Spermatic cord ( in male) or round Spermatic cord ( in male) or round

ligament ( in female)ligament ( in female)

B -Deep Inguinal RingB -Deep Inguinal RingSiteSite::

It is a small opening in the lower It is a small opening in the lower part of fascia transversalispart of fascia transversalis..

Its margins give the Its margins give the internalinternal spermatic fascia to cover the spermatic fascia to cover the spermatic cordspermatic cord..

Surface anatomySurface anatomy::

- -It lies ½ an inch above the It lies ½ an inch above the mid-point of the inguinal mid-point of the inguinal ligamentligament..

Structures passing through itStructures passing through it::

--Spermatic cord (in male) or Spermatic cord (in male) or round ligament ( in female)round ligament ( in female)..

Arteries of the Anterior Arteries of the Anterior Abdominal wallAbdominal wall

A- Above the umbilicusA- Above the umbilicus 11--superior epigastric superior epigastric arteryartery

22--musculo-phrenic arterymusculo-phrenic artery

33--lower two posterior lower two posterior intercostal and intercostal and subcostal arteriessubcostal arteries

B- Below the umbilicusB- Below the umbilicus

11--Inferior epigastric arteryInferior epigastric artery

22--Deep circumflex iliac arteryDeep circumflex iliac artery

33--Superficial branches of femoral Superficial branches of femoral arteryartery

The anterior abdominal wall is The anterior abdominal wall is drained by veins drained by veins corresponding to the arteriescorresponding to the arteries

11--Lower five intercostal and subcostal Lower five intercostal and subcostal nervesnerves

22--Illio-hypogastric and illio-inguinal Illio-hypogastric and illio-inguinal nervesnerves

..…………………..…………………

A-Above the umbilicus into pectoral A-Above the umbilicus into pectoral lymph nodeslymph nodes

B- Below the umbilicus into superficial B- Below the umbilicus into superficial inguinal lymph nodesinguinal lymph nodes

…………………………