Question 1

Which of the following best describes the role of the sarcoplasmic reticulum during skeletal muscle contraction?

Accepted Answer

It stores and releases calcium ions ($$\mathrm{Ca$$^{2+}$$}) $$necessary for muscle contraction.

Question 2

A patient is unable to relax their muscles after a contraction, resulting in sustained muscle tension. Which process is most likely impaired?

Accepted Answer

Reabsorption of calcium ions ($$\mathrm{Ca$$^{2+}$$}) by $$the sarcoplasmic reticulum

Question 3

Which connective tissue layer directly surrounds a bundle of muscle fibers (fascicle)?

Accepted Answer

Perimysium

Question 4

During a biceps curl, which muscle acts as the antagonist?

Accepted Answer

Triceps brachii

Question 5

Which of the following changes occur in the sarcomere during muscle contraction?

Accepted Answer

The I band and H zone decrease in width, while the A band remains the same.

Question 6

A sprinter relies primarily on which type of muscle fiber during a 100-meter dash?

Accepted Answer

Fast glycolytic fibers

Question 7

Which of the following best describes an isometric muscle contraction?

Accepted Answer

The muscle produces tension without changing length.

Question 8

Which structure is responsible for carrying the action potential deep into the muscle fiber, ensuring simultaneous contraction?

Accepted Answer

T-tubules (transverse tubules)

Question 9

A muscle fiber is unable to generate sufficient ATP during prolonged activity. Which of the following is a likely consequence?

Accepted Answer

Muscle fatigue due to ATP depletion

Question 10

Which of the following best describes the arrangement of muscle fibers in the deltoid muscle?

Accepted Answer

Multipennate

Question 11

Which of the following events occurs first during skeletal muscle contraction?

Accepted Answer

Acetylcholine is released into the synaptic cleft

Question 12

Which component of the thin filament blocks the active sites on actin in a relaxed muscle?

Accepted Answer

Tropomyosin

Question 13

A patient is unable to flex their elbow. Which muscle is most likely impaired?

Accepted Answer

Biceps brachii

Question 14

Which of the following best describes the 'triad' in skeletal muscle fibers?

Accepted Answer

One T-tubule and two terminal cisternae of the sarcoplasmic reticulum

Question 15

Which muscle arrangement is found in the rectus abdominis?

Accepted Answer

Parallel with tendinous bands

Question 16

Which of the following is a function of axial muscles?

Accepted Answer

Posture, breathing, and movement of the head and trunk

Question 17

During a marathon, which energy source is primarily used by skeletal muscles?

Accepted Answer

Aerobic respiration using fatty acids and glucose

Question 18

Which of the following best describes the role of a fixator muscle?

Accepted Answer

It stabilizes the origin of the agonist.

Question 19

Which of the following correctly matches the muscle with its origin and insertion?

Accepted Answer

Biceps brachii: Origin - scapula; Insertion - radius

Question 20

Which of the following best explains why shivering helps maintain body temperature?

Accepted Answer

Shivering causes muscle contractions that generate heat (thermogenesis).

Skeletal Muscle Structure and Function: Study Guide

Study Guide - Practice Questions