Muscular System

Origin

________ is where the skeletal muscle is attached to a fixed structure or bone.

lactic acid

The ________ generally moves out in the bloodstream, but the high level of exercise cause a sharp rise in ________.

Vigorous exercises

________ causes muscles to contract anaerobically (without oxygen)

Oxygen Debt

________ is the amount of oxygen needed to restore normal respirations.

Contraction of skeletal muscle

________ brings points of attachment together causing bones to move.

Prime Mover

produces movement in a single direction

Antagonist

Opposite direction

Synergist

Helps to steady movement or joint activity

Motor unit

a motor neuron plus all the muscle fiber it stimulates

Acetylcholine

chemical released when a nerve impulse is transmitted

Muscle Fatigue

caused by an accumulation of lactic acid in the muscles

Muscle Tone

muscles always in the state of partial contraction

Isotonic

when muscles contract and shorten

Isometric

Muscle tension increases but muscles does not shorten

Atrophy

Muscle shrinks from disuse

Hypertrophy

muscle size increases due to over exercise

Strength

The capacity to do work

Increases muscle size

the sarcoplasm increases, not the number of fibers

3 main responsibilities

* Body movement
* Body form and shape, to maintain posture
* Body Heat, to maintain body temperature

**Sarcolemma**

Cell Membrane

**Sarcoplasm**

Cytoplasm