An individual has just ingested a chemical that binds irreversibly to the ACh receptors in the sarcolemma. By itself it does not alter membrane potential, yet prevents normal neurotransmitter binding. Ignoring the effects on any other system, the consequence to skeletal muscle would be ________.

An individual has just ingested a chemical that binds irreversibly to the ACh receptors in the sarcolemma. By itself it does not alter membrane potential, yet prevents normal neurotransmitter binding. Ignoring the effects on any other system, the consequence to skeletal muscle would be ________. 

A) irreversible contraction as soon as the first nervous stimulation reached the sarcolemma
B) no contraction at all by nervous mechanisms
C) contraction if stimulated by an external electrode
D) no contraction at all by nervous mechanisms, but contraction if stimulated by an external electrode

Answer: D

Hypothetically, if a muscle were stretched to the point where thick and thin filaments no longer overlapped ________.

Hypothetically, if a muscle were stretched to the point where thick and thin filaments no longer overlapped ________. 

A) cross bridge attachment would be optimum because of all the free binding sites on actin
B) no muscle tension could be generated
C) maximum force production would result since the muscle has a maximum range of travel
D) ATP consumption would increase since the sarcomere is "trying" to contract

Answer: B

Of the following muscle types, which has only one nucleus, no sarcomeres, and rare gap junctions?

Of the following muscle types, which has only one nucleus, no sarcomeres, and rare gap junctions? 

A) visceral smooth muscle
B) multiunit smooth muscle
C) cardiac muscle
D) skeletal muscle

Answer: B

Three discrete types of muscle fibers are identified on the basis of their size, speed, and endurance. Which of the following athletic endeavors best represents the use of red fibers?

Three discrete types of muscle fibers are identified on the basis of their size, speed, and endurance. Which of the following athletic endeavors best represents the use of red fibers? 

A) a sprint by an Olympic runner
B) a long, relaxing swim
C) playing baseball or basketball
D) mountain climbing

Answer: B

The most distinguishing characteristic of muscle tissue is ________.

The most distinguishing characteristic of muscle tissue is ________. 

A) the design of the fibers
B) the sarcoplasmic reticulum
C) the diversity of activity of muscle tissue
D) the ability to transform chemical energy into mechanical energy

Answer: D

Which of the following is most accurate?

Which of the following is most accurate? 

A) Muscle tension remains relatively constant during isotonic contraction.
B) T-tubles may be sliding during isotonic contraction.
C) The I band lenghtens during isotonic contraction.
D) Myofilaments slide during isometric contractions.

Answer: A