Question 1

Which of the following best describes the property of muscle excitability?

Accepted Answer

Ability to receive nerve stimuli and conduct an impulse across its plasma membrane

Question 2

A patient presents with muscle stiffness after death, known as rigor mortis. What is the primary cause of this phenomenon?

Accepted Answer

Lack of ATP required to break actin-myosin cross-bridges

Question 3

Which connective tissue layer surrounds individual muscle fibers?

Accepted Answer

Endomysium

Question 4

During muscle contraction, which protein blocks the myosin binding sites on actin when Ca$$^{2+}$$ concentration is low?

Accepted Answer

Tropomyosin

Question 5

Which of the following equations correctly represents the reaction catalyzed by creatine kinase during muscle relaxation?

Accepted Answer

$$\mathrm{CP} + \mathrm{ADP} \rightarrow \mathrm{ATP} + \mathrm{Creatine}$$

Question 6

Which muscle fiber type is most resistant to fatigue and is best suited for endurance activities?

Accepted Answer

Slow oxidative fibers

Question 7

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

Accepted Answer

Isometric contraction

Question 8

Which of the following is the correct sequence of events in excitation-contraction coupling?

Accepted Answer

Release of Ca$$^{2+}$$ from sarcoplasmic reticulum $$\rightarrow$$ binding of Ca$$^{2+} to $$troponin $$\rightarrow$$ exposure of myosin binding sites on actin

Question 9

Which protein is responsible for elastic recoil in muscle after contraction?

Accepted Answer

Titin

Question 10

Which of the following statements about the neuromuscular junction is correct?

Accepted Answer

The motor end plate is the area of a muscle fiber adjacent to the motor axon terminus

Question 11

Which of the following is a consequence of oxygen depletion in muscle cells during intense exercise?

Accepted Answer

Lactic acid is produced, causing muscle fatigue

Question 12

Which of the following best describes the role of myoglobin in muscle cells?

Accepted Answer

Stores oxygen for use during muscle activity

Question 13

Which phase of a muscle twitch corresponds to the time between stimulation and initiation of contraction?

Accepted Answer

Latent period

Question 14

Which of the following is true regarding the ATP-ADP cycle in muscle contraction?

Accepted Answer

ATP must be continually regenerated for sustained contraction

Question 15

Which of the following is a function of skeletal muscle?

Accepted Answer

Movement of substances through hollow organs

Question 16

Which of the following best explains why muscle cramps most often occur?

Accepted Answer

Lack of ATP and ionic imbalances

Question 17

Which of the following is the correct formula for the energy yield of aerobic respiration per molecule of glucose?

Accepted Answer

$$	ext{Energy yield} = 36 	ext{ ATP}$$

Question 18

Which of the following muscle proteins is responsible for linking actin to the sarcolemma and is associated with Duchenne Muscular Dystrophy?

Accepted Answer

Dystrophin

Question 19

Which of the following best describes the function of the Z line in a sarcomere?

Accepted Answer

It marks the boundary of the sarcomere and anchors thin filaments

Question 20

A muscle fiber is exposed to a threshold stimulus and contracts to its fullest extent. This is an example of which principle?

Accepted Answer

All-or-none principle

Comprehensive Study Notes: Skeletal Muscle Structure, Function, and Physiology

Guida di studio - Domande di pratica

Study guide - Flashcard