MUSCULAR SYSTEM

1. Muscle Vocabulary2. Introduction to Muscles Worksheet3. Microscopic Anatomy of Muscles4. Vocabulary Quiz5. Muscle Hodge Podge6. Skeletal Muscles (36 presentations)7. Muscle Labels8. Movement Lab9. Energy Used for Muscle Contractions10.Muscular System Diseases

TOPIC #4: Muscular System

• Name• Bone of Origin• Bone of insertion• Joint crosses• Why named?• Action• Antagonistic muscle (if any)

SKELETAL MUSCLE PRESENTATIONS

1. Threshold stimulus2. Motor neuron3. Fascicle4. Myosin/Actin5. Sarcomere6. Cholinterase7. Acetylcholine8. Muscle Cramp9. All-or-none Response10. Atrophy vs. Atony11. Muscle tone12. Myostatin13. Agonists14. Antagonists15. Synergists16. Fixators

MUSCLE VOCABULARY

• Latin word mus? Little mouse• 3 types of muscles? Skeletal, cardiac, smooth• Striated?• Tendons?• Housekeeping muscles?• Functions of muscles?• Key words:– Skeletal: skeletal, striated, voluntary– Smooth: involuntary, visceral, non-striated– Cardiac: cardiac, involuntary, striated

• Cardiac muscle: HEART• Contracting: muscle shortens

BASIC TRAINING

MICROSCOPIC ANATOMY

Contains cells, nerve fibers, connective tissues, blood vessels

Covered externally by epimysium

Bundle of cells, separated by connective tissue sheath

Surrounded by perimysium

Elongated, multiple cells, multinucleate, has striated appearance

Surrounded by endomysium

MICROSCOPIC ANATOMY

MUSCLE FIBERS ARE NOT SINGLE CELLS!•They are a FUSION of many cells = myoblastsEach Muscle Fiber Contains:•An array of myofibrils•Mitochondria – responsible for Cellular RespirationConvert chemical energy (food) into cellular energy (ATP) Also called sarcosomes•Many nuclei (multi-nucleate)•Sarcolemma = cell membrane•Sarcoplasmic reticulum = ER•Sarcoplasm??•Sarcomere…

• Muscle fibers are STRIATED• Myofibrils are made up parallel

filaments (thick & thin) • Striations are created by dark A

bands and light I bands• A bands are bisected by the M

line• I bands are bisected by the Z disk• Thick filaments produce the dark

A band & contain myosin• Thin filaments produce the light I

band & contain actin

SARCOMERES

Entire array of thick and thin filaments between Z disks

video

Read pages 166 and 167WRITE OUT QUESTIONS AND ANSWERS PLEASE!

1. What split ATP to generate power for muscle contraction?

2. What links the thick and thin filaments together during muscle contraction?

3. Why does the light, H zone seem to disappear during muscle contraction?

4. What is the major role of the SR?5. What provides the “go” signal for muscle

contraction?Also answer #1 on page 198 and #3 on page 199

#5MUSCLE HODGE PODGE

Golden Rules of Muscle Activity1. All muscles cross at least one joint.2. Typically, the bulk of the muscle lies

PROXIMAL to the joint crossed.3. All muscles have at least 2 attachments:

the origin and the insertion.4. Muscles can only pull, they never push.5. During contraction, the muscle insertion

moves toward the origin.

Points of muscle attachment in bone

Origin = less movable bone

Insertion = movable bone; moves toward origin when contracting

• Body movement occurs when muscles contract across joints– Flexion, Extension, Hyperextension–Rotation (lateral = away vs. medial = towards)–Abduction (away from midline), Adduction

(toward midline)–Circumduction – FOOT: Dorsiflexion, Plantar Flexion, Inversion,

Eversion, – Supination, Pronation–Opposition–Elevation, Depression, Retraction, Protraction

• Elevation: scapula is raised, “shrugging the shoulders”• Depression: scapula pulls down to a

more inferior position• Protraction: scapula moves forward,

“hunching the shoulders”• Retraction: scapula moves backward,

“squaring the shoulders”

• Muscles CANNOT push! • Muscles must work in REVERSE pairs to move

the bones.• Immense variety of movement possible–Prime mover: muscle with majority of

responsibility of causing movement–Antagonists: oppose/reverse a movement– Synergists: help prime movers by producing

same movement or lessening other movements– Fixators: specialized synergists, used for

stabilizing purposes

Muscles are named, based on various characteristics.•Location example: tibialis anterior is located near the front of the tibia bone. •Size: example: maximus means larger & minimus means smaller. (pectoralis major & minor muscles of the chest)

Naaaammmme That Muscle!

•Number of origins/insertions: based on the number of origins, example: quadriceps femoris (which has 4 = quad)•Fiber direction: example: rectus (straight) runs parallel to midline of body. Oblique run slanted to midline of the body.•Muscle shape: example: deltoid means triangular•Muscle action: example: flexor, adductor, extensor

–Facial Muscles–Neck Muscles–Anterior Trunk Muscles–Posterior Trunk Muscles–Upper Limb Muscles–Lower Limb Muscles

Important Skeletal Muscles

#6 Muscle Mania

Muscles of the Human Body Muscles of the head and neck: The muscles of the face and head can be divided into 3 main categories: (A) muscles of expression – orbicularis, buccinator, frontalis, occipitalis (B) muscles of chewing – masseter, temporalis and (C) muscles of the neck – sternocleidomastoid. Muscles of the Neck and Shoulder: Sternocleidomastoid, Trapezius, Deltoid, Rotator Cuff: is a group of 4 muscles which hold the head of the arm bone in the shoulder joint and attach the arm to the chest. Muscles of the Chest and Back: muscle of the chest includes - Pectoralis Major, Pectoralis Minor and Intercostal Muscles. The muscles of the back include – Trapezius, Latissimus Dorsi and Serratus Posterior. Muscles of the Upper Extremity: the muscles of the upper arm include – Coracobrachialis, Biceps, Brachialis and the Triceps muscle. The muscles of the forearm include - Pronator Teres, Extensor Digitorum Communis and the Flexor Carpi Radialis. Muscles of the hand include - Palmaris Brevis, Abductor Digiti Quinti, Abductor Pollicis Brevis and the Flexor Pollicis Brevis muscle. Muscles of the Lower Extremity: the muscles of the thigh and shin region include - Quadriceps Muscles, Hamstring Muscles, Tibialis Anterior, Calf Muscles and yhe Extensor Digitorum Longus muscle. The muscles of the foot include - Plantar Aponeurosis, Abductor Hallucis, Flexor Digitorum Brevis and the Abductor Digiti Quinti.

What’s the difference??

Aging

Muscular System Diseases• Usually extremely painful, result in

physical impairments (such as an inability to walk).Nerve damageMuscular DystrophyMyasthenia GravisALSCerebral palsyTorticollis