Q: Which equation correctly represents the sodium-potassium pump activity during the restoration of ionic balance after an action potential?

$$3\ \text{Na}^+ \ \text{(out)} + 2\ \text{K}^+ \ \text{(in)}$$

Question 1

Which of the following statements correctly describes the structural and functional differences between skeletal, cardiac, and smooth muscle tissue?

Accepted Answer

Skeletal muscle is voluntary, striated, and multinucleated; cardiac muscle is involuntary, striated, and has intercalated discs; smooth muscle is involuntary, non-striated, and has one nucleus.

Question 2

During muscle contraction, which sequence of events correctly describes the excitation-contraction coupling process?

Accepted Answer

Action potential travels down the sarcolemma into T-tubules, Ca$$^{2+} is $$released from the terminal cisternae, Ca$$^{2+}$$ binds to troponin, myosin binds to actin, and ATP is hydrolyzed for cross-bridge formation.

Question 3

A patient is experiencing muscle fatigue after intense exercise. Which metabolic pathway is primarily responsible for the rapid production of ATP during this period, and what is the net ATP yield per glucose molecule?

Accepted Answer

Anaerobic respiration; $$2$$ ATP per glucose

Question 4

Which of the following best explains why rigor mortis occurs after death?

Accepted Answer

ATP is unavailable, preventing myosin from detaching from actin, resulting in sustained cross-bridges.

Question 5

Which equation correctly represents the sodium-potassium pump activity during the restoration of ionic balance after an action potential?

Accepted Answer

$$3\ 	ext{Na}^+ \ 	ext{(out)} + 2\ 	ext{K}^+ \ 	ext{(in)}$$

Question 6

A muscle fiber is stimulated repeatedly before it has a chance to fully relax. Which phenomenon is most likely to occur, and what is the physiological consequence?

Accepted Answer

Incomplete tetanus; unfused wave summation resulting in abnormal muscle contraction

Question 7

Which muscle fiber type is best suited for endurance activities such as marathon running, and why?

Accepted Answer

Slow oxidative fibers; high oxygen environment, fatigue-resistant, and aerobic metabolism

Question 8

Which of the following correctly matches the muscle and its primary function?

Accepted Answer

Biceps brachii – Prime mover of elbow flexion

Question 9

A muscle with fibers that converge on both sides of a central tendon, giving it a feathered appearance, is classified as which type of fascicle arrangement?

Accepted Answer

Bipennate

Question 10

In a third-class lever system, which arrangement is correct for the location of the effort, load, and fulcrum?

Accepted Answer

Fulcrum – Effort – Load

Question 11

Which neurotransmitter is released by motor neurons to stimulate skeletal muscle contraction, and what is its effect on the postsynaptic membrane?

Accepted Answer

Acetylcholine (ACh); depolarizes the membrane (EPSP)

Question 12

Which glial cell is responsible for producing myelin sheaths in the central nervous system, and what is myelin primarily composed of?

Accepted Answer

Oligodendrocytes; lipids

Question 13

A neuron receives multiple EPSPs in rapid succession. What is the likely outcome, and which type of channel is primarily involved?

Accepted Answer

Summation leads to an action potential; ligand-gated channels

Question 14

Which equation best represents the ATP yield from aerobic respiration of one glucose molecule in muscle cells?

Accepted Answer

$$	ext{C}_6	ext{H}_{12}	ext{O}_6 + 6\ 	ext{O}_2 ightarrow 6\ 	ext{CO}_2 + 6\ 	ext{H}_2	ext{O} + 36\ 	ext{ATP}$$

Question 15

Which of the following best describes the difference between graded potentials and action potentials?

Accepted Answer

Graded potentials occur on dendrites and cell bodies, decrease in amplitude, and open ligand-gated channels; action potentials occur on axons, are all-or-none, and open voltage-gated channels.

Question 16

Which neurotransmitter is deficient in Parkinson’s disease and is associated with reward and pleasure?

Accepted Answer

Dopamine

Question 17

Which muscle is responsible for closing the eye, blinking, and squinting?

Accepted Answer

Orbicularis oculi

Question 18

Which of the following best describes the function of the diaphragm?

Accepted Answer

Normal breathing in and out

Study Guide: Muscle Tissue, Muscular System, and Fundamentals of the Nervous System (Chapters 9–11)

Study Guide - Practice Questions

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