Question 1

Which of the following best describes the role of the sarcomere in muscle contraction?

Accepted Answer

It is the basic contractile unit of muscle fibers, where actin and myosin interact to produce contraction.

Question 2

During the excitation-contraction coupling in skeletal muscle, what is the primary effect of calcium ions released from the sarcoplasmic reticulum?

Accepted Answer

Calcium ions bind to troponin, causing a conformational change that exposes binding sites on actin for myosin.

Question 3

Which equation correctly represents the net ATP yield from aerobic metabolism of one glucose molecule in skeletal muscle?

Accepted Answer

$$38 	ext{ ATP}$$

Question 4

A patient presents with muscle fatigue after short bursts of intense activity. Which energy system is most likely depleted?

Accepted Answer

Direct phosphorylation by creatine phosphate

Question 5

Which of the following best describes the difference between isotonic and isometric muscle contractions?

Accepted Answer

Isotonic contractions involve muscle length change, while isometric contractions involve tension without length change.

Question 6

Which neurotransmitter is most commonly associated with the initiation of muscle contraction at the neuromuscular junction?

Accepted Answer

Acetylcholine

Question 7

If a neuron is hyperpolarized, which of the following is most likely occurring at the membrane?

Accepted Answer

Efflux of potassium ions ($$K^+)$$

Question 8

Which of the following correctly describes the sequence of events during an action potential?

Accepted Answer

Depolarization, repolarization, hyperpolarization

Question 9

Which type of neuron would most likely be found in the retina, based on its structure?

Accepted Answer

Bipolar neuron

Question 10

A drug blocks voltage-gated sodium channels in neurons. What is the most likely effect on the action potential?

Accepted Answer

Action potentials will not be generated.

Question 11

Which of the following best explains the effect of GABA as a neurotransmitter?

Accepted Answer

GABA is an inhibitory neurotransmitter that causes hyperpolarization of the postsynaptic membrane.

Question 12

Which of the following is a correct description of the organization of skeletal muscle from largest to smallest?

Accepted Answer

Muscle, fascicle, fiber, myofibril, sarcomere

Question 13

Which of the following would most likely result from blocking acetylcholine receptors at the neuromuscular junction?

Accepted Answer

Muscle contraction would be inhibited.

Question 14

Which of the following is the correct formula for the resting membrane potential of a neuron, using the Nernst equation?

Accepted Answer

$$E = \frac{RT}{zF} \ln \left( \frac{[	ext{ion outside}]}{[	ext{ion inside}]} ight)$$

Question 15

Which of the following is an example of a muscle agonist-antagonist pair?

Accepted Answer

Biceps brachii and triceps brachii

Question 16

Which process is responsible for the rapid repolarization phase of the neuronal action potential?

Accepted Answer

Opening of voltage-gated potassium channels

Question 17

A patient is given a drug that increases extracellular potassium concentration. What effect will this have on the resting membrane potential?

Accepted Answer

It will make the resting membrane potential less negative (depolarized).

Question 18

Which of the following best describes the effect of an inhibitory neurotransmitter on a postsynaptic neuron?

Accepted Answer

It decreases the likelihood of an action potential by hyperpolarizing the membrane.

Question 19

Which of the following is a correct description of the effect of sodium-potassium ATPase on the neuronal membrane?

Accepted Answer

It pumps 3 $$Na^+$$ ions out and 2 $$K^+$$ ions in, maintaining the resting membrane potential.

Muscle and Nervous Tissue: Study Guide for Anatomy & Physiology

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