Skeletal Muscle Part 2

Root Words

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

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

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)

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

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

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

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

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

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.

Create flash cards of the following major muscle groups using pages 193- 205 Front: name of muscle Back: