$$\text{Phosphocreatine} + \text{ADP} \rightarrow \text{Creatine} + \text{ATP}$$

$$\text{ATP} + \text{H}_2\text{O} \rightarrow \text{ADP} + \text{Pi} + \text{energy}$$

Question 1

Which of the following best describes the organization of skeletal muscle from largest to smallest structural unit?

Accepted Answer

Muscle fiber, myofibril, sarcomere, actin/myosin

Question 2

During skeletal muscle contraction, which event directly triggers the release of calcium from the sarcoplasmic reticulum?

Accepted Answer

Depolarization of the T-tubule membrane

Question 3

Which equation correctly represents the reaction catalyzed by creatine kinase in skeletal muscle?

Accepted Answer

$$	ext{Phosphocreatine} + 	ext{ADP} ightarrow 	ext{Creatine} + 	ext{ATP}$$

Question 4

A patient is experiencing muscle weakness and rapid fatigue during exercise. Which muscle fiber type is most likely deficient?

Accepted Answer

Fast-twitch glycolytic fibers

Question 5

Which of the following statements about smooth muscle is TRUE?

Accepted Answer

Smooth muscle contraction is regulated by myosin phosphorylation

Question 6

In skeletal muscle, what is the primary function of titin?

Accepted Answer

Providing elasticity and stabilizing the thick filament

Question 7

Which scenario best illustrates the concept of motor unit recruitment?

Accepted Answer

A person gradually increases the force of grip by activating more motor units

Question 8

Which of the following is a key difference between single-unit and multiunit smooth muscle?

Accepted Answer

Single-unit smooth muscle contracts as a coordinated group due to gap junctions

Question 9

Which of the following best describes the role of the Golgi tendon organ in skeletal muscle reflexes?

Accepted Answer

Monitors muscle tension and inhibits excessive contraction

Question 10

During excitation-contraction coupling in skeletal muscle, which sequence of events is correct?

Accepted Answer

Acetylcholine release → depolarization of muscle fiber → calcium release → crossbridge formation

Question 11

Which brain structure is primarily responsible for planning voluntary movements?

Accepted Answer

Prefrontal cortex

Question 12

A muscle spindle is most directly involved in which type of reflex?

Accepted Answer

Stretch reflex

Question 13

Which equation represents the hydrolysis of ATP during muscle contraction?

Accepted Answer

$$	ext{ATP} + 	ext{H}_2	ext{O} ightarrow 	ext{ADP} + 	ext{Pi} + 	ext{energy}$$

Question 14

Which of the following is TRUE regarding the all-or-none principle of skeletal muscle fiber contraction?

Accepted Answer

A muscle fiber contracts fully or not at all when threshold is reached

Question 15

Which chemical signal can influence smooth muscle activity via paracrine signaling?

Accepted Answer

Nitric oxide

Question 16

Which of the following best explains why slow-twitch muscle fibers are fatigue-resistant?

Accepted Answer

They contain abundant mitochondria and rely on oxidative metabolism

Question 17

Which event occurs during the rigor state in skeletal muscle contraction?

Accepted Answer

Myosin remains bound to actin due to lack of ATP

Question 18

Which of the following is a direct effect of increased MLCP (myosin light chain phosphatase) activity in smooth muscle?

Accepted Answer

Relaxation of smooth muscle

Question 19

A person touches a hot stove and quickly withdraws their hand. Which neural pathway is primarily responsible for executing this movement?

Accepted Answer

Prefrontal cortex → primary motor cortex → spinal cord → somatic motor neuron

Question 20

Which of the following best describes the role of the cerebellum in movement control?

Accepted Answer

Coordinates and refines movement based on sensory input

Skeletal and Smooth Muscle: Structure, Function, and Control (Chapters 12 & 13)

Study Guide - Practice Questions