Muscular System

Types of Muscle Tissue:

1. Skeletal - moves bones, contract by will.  Striated or striped in appearance- voluntary

2. Visceral - not consciously controlled, smooth muscle - involuntary

3. Cardiac- involuntary unique to the heart, ability to contract continuously

Anatomy of Muscles

1. Bundles of Fibers

2. Nerve and Blood Supply

3. Muscle Attachments - Tendon - attaches muscle to bone.  Aponeurosis - broad attachment attaches muscles to bones or other muscles. Fascia - broad sheets of connective tissue that holds muscles together

Physiology

   Properties:

1.  Contractility - the ability of tissue to shorten and thicken; also the ability of the tissue to do the work

2. Extensibility - the ability of the tissue to be stretched

3. Elasticity - the ability of the tissue to return to its original shape after being shortened or stretched

4. Irritability -  excitability capacity to respond to stimulus

5. Excitability/Conductivity - ability of tissue to receive and respond to stimuli; spreads transmission over surface in response to nerve impluse which allows whole unit to contract

Function of Muscle Tissue:

1. Form the shape of the body.  In neutral or contracted state, the muscles form our exterior shape

2. Generate Heat - As muscles contract, they generate heat

3. Initiate movement

4. maintain posture - imbalances in the posture occur when there is unbalanced muscle contraction

Muscle Contraction:

1.  Stimulus - anything that causes a muscle to contract

2. All or None principle

3. Fatigue - lactic acid, oxygen debt

4. Muscle tone - muscles ability to stay partially contracted

Function:

1.    Movement - origin - less movable; fixed attachment. Insertion - attachment to part of the body that muscle pulls into action.

2. Prime Mover- main muscle that accomplishes movement
   Synergist - helpers to prime movers
   Antagonist - produce opposing movement
   Fixator - Fix a point of body so other muscles can move agains Point.

3. Terminology

4. Joint Movements

5. Exercise

Disorders of Muscles

1.  Strain - detachment of muscle from bone or tearing
    Sprain - ligament injuries, blood vessels and nerves involved
    Cramps

2. Atrophy - wasting or decrease of muscle

3. Myalgia - muscle pain
   Myosytis - inflammation of muscle tissue - loss of function
   Fibrositis -inflammation of connective tissues of muscles and joints
   Bursitis - inflammation of fluid filled sac that minimizes friction between tissues and bone

4. Muscular Dystrophy

5. Myesthena Gravis - fatigue of muscles