1. Skeletal Muscle Part 2

2. Root Words

3. Hemoglobin
Pigment in red blood cells that carry oxygen to the rest of the body. Responsible for the red color of blood

4. Myoglobin
Another pigment synthesized in muscle cell that gives it the reddish-brown color.
Temporarily stores oxygen which reduces need for continuous blood supply during muscle contraction

5. Muscle Fatigue
A muscle exercised strenuously for a prolonged period may lose ability to contract
Arises from accumulation of lactic acid in the muscle as a result of anaerobic respiration (lack of oxygen)

6. Threshold Stimulus
A certain amount of stimulation must be applied before a muscle fiber becomes responsive
Once reached, the action potential is generated

7. Muscle Tone
Sustained contraction, even when muscles appear to be at rest
Constantly stimulated, to maintain poster. If someone loses consciousness, the body collapses.

8. Sphincter
Muscle that relax and constrict passage ways to release or stop bodily fluids
Over 50 types in the body
Example: Anus, Iris of the eye, stomach, intestine

9. Smooth Muscle Fibers
Elongated, cell muscles. Also contain myosin and actin.
2 main types
Multiunit Smooth Muscle
Visceral Smooth Muscle

10. Multiunit Smooth Muscle
Muscle fibers are separate rather than organized into sheets
Found in the irises of the eye and walls of blood vessels.
Only respond to stimulation by motor nerve impulses or certain hormones

11. Visceral Smooth Muscle
Composed of sheets of spindle-shaped cells in close contact with one another.
Found in the walls of organs such as stomach, intestines, bladder, and uterus
Can stimulate each other, once one is stimulated, the impulse moves to excite adjacent fibers.

12. Create flash cards of the following major muscle groups using pages Front: name of muscle Back: