$$\text{CP} + \text{ADP} \xrightarrow{\text{creatine kinase}} \text{ATP} + \text{creatine}$$

$$\text{Glucose} + 6\text{O}_2 \rightarrow 6\text{CO}_2 + 6\text{H}_2\text{O} + 32\text{ATP}$$

Question 1

Which connective tissue layer directly surrounds each individual muscle fiber in skeletal muscle?

Accepted Answer

Endomysium

Question 2

Which of the following is a unique characteristic of cardiac muscle tissue compared to skeletal and smooth muscle?

Accepted Answer

It is striated and contracts at a steady rate due to its own pacemaker

Question 3

During muscle contraction, which event occurs first at the neuromuscular junction?

Accepted Answer

Voltage-gated calcium channels open in the axon terminal

Question 4

Which equation best represents the direct phosphorylation of ADP by creatine phosphate?

Accepted Answer

$$	ext{CP} + 	ext{ADP} \xrightarrow{	ext{creatine kinase}} 	ext{ATP} + 	ext{creatine}$$

Question 5

Which statement best describes the 'all or none principle' of action potentials in muscle fibers?

Accepted Answer

Once threshold is reached, the action potential is always a full response

Question 6

Which of the following is TRUE regarding the sliding filament model of muscle contraction?

Accepted Answer

Thin filaments slide past thick filaments, increasing overlap

Question 7

A patient with Duchenne muscular dystrophy is likely to experience muscle weakness due to which cellular defect?

Accepted Answer

Defective dystrophin protein causing sarcolemma instability

Question 8

Which of the following is NOT a function of ATP in muscle contraction?

Accepted Answer

Initiating the action potential in the motor neuron

Question 9

Which of the following best describes an isometric muscle contraction?

Accepted Answer

Muscle tension increases but the muscle does not shorten

Question 10

Which equation represents the net ATP gain from aerobic respiration of one glucose molecule?

Accepted Answer

$$	ext{Glucose} + 6	ext{O}_2 ightarrow 6	ext{CO}_2 + 6	ext{H}_2	ext{O} + 32	ext{ATP}$$

Question 11

Which of the following is a regulatory protein found in thin filaments that helps control muscle contraction?

Accepted Answer

Troponin

Question 12

During depolarization of the muscle fiber membrane, which ion primarily enters the cell?

Accepted Answer

Sodium ($$	ext{Na}^+)$$

Question 13

Which structure is the smallest contractile unit of a skeletal muscle fiber?

Accepted Answer

Sarcomere

Question 14

Which of the following best describes the function of the sarcoplasmic reticulum in muscle fibers?

Accepted Answer

Stores and releases calcium ions

Question 15

Which of the following is TRUE about the energy systems used during a 100-meter sprint?

Accepted Answer

Direct phosphorylation by creatine phosphate provides ATP for the first few seconds

Question 16

Which statement correctly describes the role of acetylcholinesterase at the neuromuscular junction?

Accepted Answer

It degrades acetylcholine in the synaptic cleft

Question 17

Which of the following is a consequence of rigor mortis after death?

Accepted Answer

Calcium cannot be pumped back into the sarcoplasmic reticulum, resulting in sustained contraction

Question 18

Which of the following is TRUE regarding concentric and eccentric isotonic contractions?

Accepted Answer

Concentric contractions shorten the muscle and do work, while eccentric contractions lengthen the muscle and generate force

Question 19

Which of the following best describes the arrangement of myofilaments in a sarcomere?

Accepted Answer

Thin filaments are anchored to the Z disc, thick filaments to the M line

Muscle Tissue: Structure, Function, and Contraction

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