The Muscular System Anatomy & Physiology

Overview of Muscle Tissues 3 Types of Muscle Tissue: 1.Skeletal 2.Cardiac 3.Smooth

Skeletal Muscle Attach to/cover bony skeleton Attach to/cover bony skeleton Surrounds cavities, eyes, tongue Surrounds cavities, eyes, tongue Striations Striations Voluntary (somatic) muscle - Only type of muscle consciously controlled Voluntary (somatic) muscle - Only type of muscle consciously controlled

Skeletal Muscle

Cardiac Muscle Only found in heart Only found in heart Striated Striated Involuntary muscle control Involuntary muscle control  (autonomic)

Cardiac Muscle

Smooth Muscle Tissue Found in: Walls of visceral organs, blood vessels, reproductive ducts, respiratory passages, hair follicles, eyes (pupil) Walls of visceral organs, blood vessels, reproductive ducts, respiratory passages, hair follicles, eyes (pupil) –Not striated –Peristalsis Involuntary control Involuntary control  (autonomic)

Smooth Muscle

Functional Characteristics of Muscle Tissue 1. Irritability- responds to stimulus 2. Contractility- can shorten (muscle fibers overlap) 3. Extensibility- can be stretched Elasticity- can return to original shape after extension or flexion Muscle stretched beyond limit = STRAIN

4 Functions of Muscle –Producing movement- contractions move body parts, substances (blood, urine, food); diaphragm for breathing –Maintaining posture –Stabilizing joints –Generating heat

Gross Anatomy of Skeletal Muscle Sarcolemma- cell membrane of muscle fiber Connective Tissue Sheaths 1. Endomysium- surrounds muscle fiber 2. Perimysium- bundles muscle fibers into a fascicle 3. Epimysium- surrounds entire muscle

Attachments Belly- main body of muscle Belly- main body of muscle Origin- doesn’t move (attachment site) Origin- doesn’t move (attachment site) Insertion- moveable attachment Insertion- moveable attachment Tendon Tendon –Aponeurosis- flat, sheet-like tendon; anchors muscle to other tissues

Contraction Concentric Concentric –Agonist vs. antagonist Eccentric Eccentric Isometric Isometric

Movements Flex- decrease angle of joint Flex- decrease angle of joint Extend- increase angle of joint Extend- increase angle of joint Abduct- pull away Abduct- pull away Adduct- pull in Adduct- pull in Rotate- spin Rotate- spin Supinate- lateral rotate Supinate- lateral rotate Pronate-medial rotate Pronate-medial rotate Invertion- move in Invertion- move in Evertion- move out Evertion- move out Circumduction Circumduction Opposition Opposition