Question 1

Which of the following best describes the function of acetylcholinesterase at the neuromuscular junction?

Accepted Answer

It breaks down acetylcholine in the synaptic cleft, terminating the signal for muscle contraction.

Question 2

A patient is unable to extend their arm at the shoulder joint. Which muscle is most likely impaired?

Accepted Answer

Latissimus dorsi

Question 3

During the contraction cycle, which event occurs immediately after calcium ions bind to troponin?

Accepted Answer

Tropomyosin shifts to expose active sites on actin.

Question 4

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

Accepted Answer

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

Question 5

A muscle is producing near maximum tension due to rapid cycles of contraction and relaxation. Which term best describes this phenomenon?

Accepted Answer

Incomplete tetanus

Question 6

Which neurotransmitter is released at the neuromuscular junction to stimulate skeletal muscle contraction?

Accepted Answer

Acetylcholine

Question 7

If sodium-potassium pumps in a neuron are inhibited, what will happen to the resting membrane potential?

Accepted Answer

The resting membrane potential will be lost, approaching zero.

Question 8

Which of the following best describes a first-class lever in the human body?

Accepted Answer

The fulcrum is between the load and the applied force.

Question 9

Which structure anchors the thin filaments in a sarcomere?

Accepted Answer

Z line

Question 10

A patient presents with muscle weakness. Laboratory tests reveal a deficiency in acetylcholine at the neuromuscular junction. Which of the following is the most likely effect?

Accepted Answer

Decreased muscle contraction

Question 11

Which of the following is true regarding the I band of a sarcomere?

Accepted Answer

It contains only thin filaments and titin.

Question 12

Which muscle is primarily responsible for abduction of the shoulder?

Accepted Answer

Deltoid

Question 13

Which of the following best describes the function of the sodium-potassium pump in neurons?

Accepted Answer

It actively transports $$3 \ Na^+$$ out and $$2 \ K^+$$ into the cell, maintaining the resting membrane potential.

Question 14

Which of the following is a function of skeletal muscle?

Accepted Answer

All of the above

Question 15

Which of the following best describes the 'zone of overlap' in a sarcomere?

Accepted Answer

It is the region where thick and thin filaments overlap.

Question 16

A decrease in which neurotransmitter is most closely associated with Parkinson-like symptoms?

Accepted Answer

Dopamine

Question 17

Which of the following best describes an isometric muscle contraction?

Accepted Answer

The muscle produces tension without changing length.

Question 18

Which cranial nerve controls the lateral rectus muscle of the eye, allowing for abduction?

Accepted Answer

Abducens nerve (CN VI)

Question 19

Which of the following best describes the function of titin in the sarcomere?

Accepted Answer

It anchors thick filaments to the Z line and provides elasticity.

Question 20

A patient is unable to smile on one side of their face. Which muscle is most likely affected?

Accepted Answer

Zygomaticus major

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

Guida di studio - Domande di pratica

Study guide - Flashcard