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, tropomyosin shifts to expose myosin binding sites on actin, ATP binds to myosin, cross-bridge forms.

Question 3

A patient is experiencing muscle weakness after prolonged exercise. Which metabolic pathway is most likely depleted, and how much ATP does it produce per glucose molecule?

Accepted Answer

Anaerobic respiration; produces $$2$$ ATP per glucose molecule.

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 muscle fiber type is best suited for endurance activities, and what is its primary metabolic pathway?

Accepted Answer

Slow oxidative fibers; aerobic metabolism.

Question 6

A muscle contraction in which the muscle length does not change, but tension increases, is called:

Accepted Answer

Isometric contraction.

Question 7

Which neurotransmitter is released at the neuromuscular junction to initiate skeletal muscle contraction, and what is its effect on the postsynaptic membrane?

Accepted Answer

Acetylcholine; depolarizes the postsynaptic membrane (EPSP).

Question 8

Which of the following correctly describes the function of the Na$$^+/K$^+$$ pump during the restoration of resting membrane potential?

Accepted Answer

Pumps three Na$$^+$$ out of the cell and two K$$^+$$ into the cell.

Question 9

A neuron receives multiple EPSPs in rapid succession. What is the likely outcome?

Accepted Answer

The membrane depolarizes and may reach threshold, resulting in an action potential.

Question 10

Which glial cell is responsible for producing myelin sheaths in the central nervous system (CNS)?

Accepted Answer

Oligodendrocyte.

Question 11

A muscle named 'flexor carpi radialis' is named based on which characteristics?

Accepted Answer

Action and location.

Question 12

Which lever system is most common in the human body, and what is its arrangement?

Accepted Answer

Third-class lever; effort between fulcrum and load.

Question 13

Which muscle is the prime mover of arm abduction at the shoulder?

Accepted Answer

Deltoid.

Question 14

During an action potential, what is the value of the threshold membrane potential, and what ion movement initiates depolarization?

Accepted Answer

Threshold is $$-55 mV$$; Na$$^+$$ enters the cell.

Question 15

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

Accepted Answer

Dopamine.

Question 16

Which type of conduction occurs in myelinated axons, and what is its main advantage?

Accepted Answer

Saltatory conduction; allows for rapid transmission by leaping from Node of Ranvier to Node of Ranvier.

Question 17

Which muscle group is responsible for extending the knee, and which muscles are included in this group?

Accepted Answer

Quadriceps; rectus femoris, vastus lateralis, vastus medialis, vastus intermedius.

Question 18

Which of the following best describes the effect of norepinephrine on smooth muscle?

Accepted Answer

Relaxes bronchioles and contracts blood vessels.

Question 19

A patient is given a drug that blocks acetylcholinesterase. What is the expected effect on skeletal muscle contraction?

Accepted Answer

Muscle contraction will be prolonged due to continued presence of acetylcholine in the synaptic cleft.

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

Study Guide - Practice Questions

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