Defintions Twitch, Tetanus, Motor Unit, Recruitment, Isotonic, Isometric, Concentric Eccentric Contractions

Question 1

What is a twitch in muscle physiology?

Answer 1

A twitch is a single contraction and relaxation of a muscle fiber in response to a single stimulus.

Question 2

True or False: Tetanus is characterized by a sustained contraction without relaxation.

Answer 2

True

Question 3

Define a motor unit.

Answer 3

A motor unit consists of a motor neuron and all the muscle fibers it innervates.

Question 4

What is recruitment in the context of muscle contraction?

Answer 4

Recruitment refers to the process of activating additional motor units to increase muscle force.

Question 5

Fill in the blank: Isotonic contraction occurs when a muscle changes _____ while maintaining a constant tension.

Answer 5

length

Question 6

What are the two types of isotonic contractions?

Answer 6

Concentric and eccentric contractions.

Question 7

Which type of contraction shortens the muscle while generating force?

Answer 7

Concentric contraction.

Question 8

True or False: Eccentric contractions occur when a muscle lengthens under tension.

Answer 8

True

Question 9

What is the main difference between isotonic and isometric contractions?

Answer 9

Isotonic contractions involve a change in muscle length, while isometric contractions involve no change in muscle length.

Question 10

What is the role of motor units in muscle contraction?

Answer 10

Motor units are responsible for transmitting signals from the nervous system to initiate muscle contractions.

Question 11

How does the frequency of stimulation affect muscle contraction?

Answer 11

Increased frequency can lead to summation and possibly tetanus, resulting in stronger muscle contractions.

Question 12

Define the term ‘summation’ in muscle physiology.

Answer 12

Summation is the process where successive stimuli increase the strength of muscle contractions.

Question 13

What is a key characteristic of a tetanic contraction?

Answer 13

A tetanic contraction is sustained and does not allow for relaxation between stimuli.

Question 14

Fill in the blank: During _____ contraction, the muscle generates force while lengthening.

Answer 14

eccentric

Question 15

What is the physiological significance of muscle recruitment?

Answer 15

Recruitment allows the body to adjust the force of muscle contractions based on the demands of the activity.

Question 16

Which type of contraction is primarily used during activities like lifting weights?

Answer 16

Concentric contraction.

Question 17

True or False: Isometric contractions can contribute to muscle strength without changing muscle length.

Answer 17

True

Question 18

What happens during a concentric contraction?

Answer 18

The muscle shortens while contracting against resistance.

Question 19

Define the term ‘isometric contraction’.

Answer 19

An isometric contraction is a type of muscle contraction where the muscle length remains the same while generating force.

Question 20

What is the effect of muscle fatigue on twitch and tetanic contractions?

Answer 20

Muscle fatigue can reduce the strength and duration of both twitch and tetanic contractions.

Question 21

Fill in the blank: The process of activating more motor units to increase muscle force is called _____ .

Answer 21

recruitment

Question 22

What is the relationship between muscle fiber type and contraction type?

Answer 22

Different muscle fiber types (slow-twitch vs fast-twitch) influence the type of contractions they are best suited for.

Question 23

True or False: An increase in muscle length during an isotonic contraction requires a decrease in tension.

Answer 23

False

Question 24

What type of contraction is most effective for controlling the descent of a heavy load?

Answer 24

Eccentric contraction.