Latent Period, Contraction Phase And Relaxation Phase Of Single Muscle Twitch

Question 1

What are the three main phases of a single muscle twitch?

Answer 1

The latent period, contraction phase, and relaxation phase.

Question 2

True or False: The latent period is the time between the stimulus and the beginning of muscle contraction.

Answer 2

True.

Question 3

What occurs during the contraction phase of a muscle twitch?

Answer 3

Muscle fibers shorten and generate force.

Question 4

Fill in the blank: The __________ period is characterized by the muscle returning to its resting state.

Answer 4

relaxation

Question 5

How long does the latent period typically last?

Answer 5

A few milliseconds.

Question 6

What physiological processes occur during the latent period?

Answer 6

Calcium ions are released and cross-bridge cycling is initiated.

Question 7

What is the primary change in muscle length during the contraction phase?

Answer 7

Muscle length decreases as it contracts.

Question 8

True or False: The relaxation phase involves the reuptake of calcium ions into the sarcoplasmic reticulum.

Answer 8

True.

Question 9

What is the effect of muscle fatigue on the phases of a muscle twitch?

Answer 9

Muscle fatigue can prolong the relaxation phase and reduce contraction strength.

Question 10

Multiple Choice: Which phase follows the contraction phase? A) Latent B) Relaxation C) Excitation

Answer 10

B) Relaxation.

Question 11

What is the role of ATP during the relaxation phase?

Answer 11

ATP is required for the active transport of calcium back into the sarcoplasmic reticulum.

Question 12

Fill in the blank: The duration of the contraction phase is generally __________ than the latent period.

Answer 12

longer

Question 13

True or False: The speed of contraction varies between different muscle types.

Answer 13

True.

Question 14

What happens to muscle tension during the relaxation phase?

Answer 14

Muscle tension decreases as the muscle fibers lengthen.

Question 15

Define ‘twitch’ in the context of muscle physiology.

Answer 15

A twitch is a single, quick contraction and relaxation of a muscle fiber.

Question 16

What initiates the contraction phase of a muscle twitch?

Answer 16

The binding of calcium ions to troponin, exposing myosin binding sites.

Question 17

Multiple Choice: Which phase has the longest duration? A) Latent B) Contraction C) Relaxation

Answer 17

C) Relaxation.

Question 18

What is the typical duration of the contraction phase in skeletal muscle?

Answer 18

15 to 100 milliseconds.

Question 19

Fill in the blank: During the relaxation phase, the muscle returns to its __________ length.

Answer 19

resting

Question 20

True or False: The latent period is influenced by the speed of the stimulus.

Answer 20

True.

Question 21

What is the significance of the latent period in muscle contraction?

Answer 21

It allows time for calcium release and cross-bridge formation before contraction begins.

Question 22

Describe how the relaxation phase affects muscle responsiveness.

Answer 22

It allows the muscle to recover and become responsive to subsequent stimuli.

Question 23

What happens to the muscle fibers during the contraction phase at the molecular level?

Answer 23

Myosin heads bind to actin and pull, causing the filaments to slide past each other.

Question 24

Multiple Choice: Which of the following is NOT a phase of a muscle twitch? A) Latent B) Contraction C) Refractory

Answer 24

C) Refractory.

Question 25

What role does the sarcoplasmic reticulum play during the contraction and relaxation phases?

Answer 25

It stores and releases calcium ions essential for muscle contraction and relaxation.