Exam 17: Muscle Contraction

Skeletal muscles produce a major share of the heat generated by the body.

Which of the following is an incorrect statement regarding heat production?

The primary function of tropomyosin and troponin is to prevent a muscle from contracting.

Muscles contract more forcefully after they have contracted a few times.

The striations seen in skeletal muscle cells under the microscope are what part of the sarcomere?

Match each term with its corresponding description regarding the sliding-filament theory. -Protein that has cross-bridge heads that pull on the thin fiber

In smooth muscle cells, the calcium needed for contraction comes from outside the cell rather than from inside the cell as it does in striated muscle contraction.

Match each term with its corresponding description regarding the sliding-filament theory. -Protein that has receptor sites for an ion that causes it to change shape and pull another protein away from the receptor sites on the actin

Muscles with less tone than normal are described as flaccid.

Muscles with less-than-normal tone are described as in tetanus.

Differentiate among slow, fast, and intermediate fibers.

The pituitary gland is responsible for the homeostatic control of body temperature.

The A-band in a relaxed sarcomere is composed of only actin.

The sarcoplasmic reticulum continually pumps calcium ions out of the sarcoplasm and stores them in sacs.

A sarcomere is a segment of myofibril between two successive:

Actin, troponin, and tropomyosin are present on the thick myofilament.

When sarcomeres shorten, myofibrils also shorten.

Contraction of a small fraction of the total number of fibers in a muscle produces muscle tone.

Single-unit smooth muscle is another term for visceral muscle.

The protein molecule that has heads jutting out for cross-bridging is called myosin.