Deck 10: Introduction to Skeletal Muscle

Question 1

Which of the following proteins is the main component of thick filaments?

A) myosin
B) sarcoplasm
C) actin
D) myofibril

Answer 1

A

Question 2

What is the anatomical name for the tube-like structures that are open to the surface of the sarcolemma and form a portion of a triad?

A) cisternae
B) myofibril
C) sarcoplasmic reticulum
D) T-tubules

Answer 2

D

Question 3

Which of the following is a globular protein that binds to calcium?

A) tropomyosin
B) troponin
C) actin
D) myosin

Answer 3

B

Question 4

Which of the following is a double-stranded protein that blocks actin-binding sites?

A) myosin
B) DNA
C) tropomyosin
D) troponin

Question 5

What happens when a patient is poisoned by botulism?

A) increased respiratory rate
B) blurry, double vision
C) constricted pupils
D) increased acetylcholine release

Question 6

What structure of a sarcomere contains proteins that connect and stabilize thin filaments?

A) Z line
B) H band
C) I band
D) A band

Question 7

What is the anatomical name for the combination of cisternae and a transverse tubule?

A) sarcoplasmic reticulum
B) sarcolemma
C) triad
D) Z line

Question 8

What is the name for embryonic muscle cells?

A) myosins
B) myoblasts
C) myofibrils
D) myofilaments

Question 9

Which of the following is both a protein and a structural component of thin filaments?

A) actin
B) myosin
C) myofibrils
D) T-tubules

Question 10

What ion enters the muscle cell upon activation of the acetylcholine receptors?

A) sodium
B) calcium
C) potassium
D) chloride

Question 11

What is the name of the area of the sarcolemma that is associated with the neuromuscular junction?

A) junctional folds
B) synaptic terminal
C) synaptic cleft
D) motor end plate

Question 12

What structure contains proteins that stabilize the thin filaments?

A) Z line
B) M line
C) A band
D) I band

Question 13

What would most likely happen if there were a decrease in the number of acetylcholine receptors in an NMJ?

A) decreased neurotransmitter release into the synaptic cleft
B) increased sodium ion influx at the motor endplate
C) decreased action potential generation at the motor endplate
D) increased action potential generation at the motor endplate

Question 14

What is the "group name" for a motor nerve fiber and all the muscle fibers it stimulates?

A) motor end plate
B) myasthenia gravis
C) synaptic terminal
D) motor unit

Question 15

What is the cell membrane of a muscle cell called?

A) sarcolemma
B) sarcomere
C) sarcoplasmic reticulum
D) sarcoplasm

Question 16

The release of calcium ions from the sarcoplasmic reticulum in response to an action potential is known as ________.

A) power stroke
B) sliding filament theory
C) tropomyosin
D) excitation-contraction coupling

Question 17

What is it called when the myosin heads pivot and pull on the actin filaments?

A) power stroke
B) tropomyosin displacement
C) action potential
D) troponin

Question 18

Which neurotransmitter is released at the neuromuscular junction?

A) sodium
B) acetylcholine
C) glutamate
D) acetylcholinesterase

Question 19

Which structure stores calcium ions for release in the muscle cell?

A) sarcolemma
B) sarcomere
C) sarcoplasm
D) sarcoplasmic reticulum

Question 20

What is the name for the region of the sarcomere that contains only thick filaments?

A) Z line
B) A band
C) H band
D) I band