Human Biology Chapter 4: Muscular Tissue Moves the Body

Cardiac muscle

-has branching, striated cells, each with a single nucleus. -occurs in the wall of the heart. -functions in the pumping of blood. -is involuntary

Smooth muscle

-has spindle-shaped cells, each with a single nucleus. -cells have no striations. -functions in movement of substances in lumens of body. -is involuntary. -is found in blood vessel walls and walls of the digestive tract.

Skeletal muscle

A muscle that is attached to the bones of the skeleton by tendons and provides the force that moves the bones. -has striated cells with multiple nuclei. -occurs in muscles attached to skeleton. -functions in voluntary movement of body.

Explain the difference in the structure and function of skeletal, smooth, and cardiac muscle.

Skeletal muscle-voluntary movement of body; striated cells with multiple nuclei. Smooth muscle- involuntary control of blood vessels and movement of substances in lumens of organs; spindle shaped cells, each with a single nuclei. Cardiac muscle-involuntary heart contraction; branching striated cells with a single nucleus.

Describe where each type of muscle fiber is found in the body.

Skeletal muscles-attached to the skeleton; smooth muscle-blood vessels and walls of the digestive tract; cardiac muscle-walls of the heart.

Three types of vertebrate muscular tissue

Skeletal, smooth, and cardiac

Explain why smooth muscle and cardiac muscles are involuntary,and summarize what advantage this provides homeostasis.

These muscles are involuntary because many of their functions are critical to sustain life. It would be difficult to consciously constantly regulate the array of functions taking place simultaneously in the heart, lungs, digestive and urinary tract, etc.

Cardiac muscle cells are bound end to end at junctions called

intercalated disks.

Visceral muscle

smooth muscle

striated

striped

contraction

the tightening of a muscle