Neuromuscular Functions

Question 1

Motor units are preferentially recruited following the Henneman size principle which means that large motorneurons are depolarized first.

True or False?

Answer 1

False

Question 2

Under which of the following conditions does relaxation of the muscle occur?

Answer 2

when actin and myosin filaments return to their original states

Question 3

With an isometric contraction, the muscle is able to overcome external resistance.

True or False

Answer 3

False

Question 4

When lifting a constant load through a range of joint motion, the muscle is maximally contracted only at its weakest point in the range.

True of False?

Answer 4

True

Question 5

A reflex arc involves:

Answer 5

Sensory stimuli sent to the central nervous system that sends out motor signals.

Question 6

Individuals with the largest muscle cross-sections generate the most absolute force.

True or False

Answer 6

True

Question 7

Which of the following bands widens in an eccentric action as the fibre lengthens during force generation?

Answer 7

A band

Question 8

With endurance training there is a shift to higher ratios of Type I fibres and a reduction of Type IIA fibres.

True or False?

Answer 8

False

Question 9

What is not a correct statement about the sliding-filament model of muscle contraction?

Answer 9

Actin crossbridges detach from the myosin filaments with energy from ATP hydrolysis

Question 10

In certain instances, muscle fibres can be stimulated to stretch, rather than contract.

True or False?

Answer 10

False

Question 11

High intensity exercise recruits predominantly slow-twitch motor units.

True or False?

Answer 11

False

Question 12

A motorneuron consists of the cell body, several short dendritic fibres, and one long axon fibre that goes to skeletal muscle fibres.

True or False?

Answer 12

True

Question 13

What is the term that represents a repeating pattern of two vesicles and a T-tubule in each Z region?

Answer 13

Triad

Question 14

A motor unit contains only one specific muscle fibre type. Which of the following is not a muscle fibre type contained in a motor unit?

A. Type 1a
B. Type 1
C. Type 2
D. Type 2a

Answer 14

A. Type 1a

Question 15

Eccentric contractions occur when:

Answer 15

A muscle lengthens during contraction.

Question 16

There are two types of motor units which operate following the all-or-none law: one type consists of Type I fibres and the other of Type II.

True or False?

Answer 16

True

Question 17

When a muscle contracts it always shortens.

True or False?

Answer 17

False

Question 18

Muscle spindles are sensitive to both the rate of change in length as well as to the final length attained by the fibres.

True or False?

Answer 18

True

Question 19

Muscle soreness can be prevented or reduced by what?

Answer 19

Stretching, and gradual increases in activity intensity.

Question 20

What consists of the basic repeating unit between two Z lines and makes up the functional unit of the skeletal muscle?

Answer 20

sarcomere

Question 21

What principle states that slow-twitch motor units with the lowest threshold for activation become selectively recruited during light-to-moderate effort?

Answer 21

size principle

Question 22

Male and female athletes have?

Answer 22

The same fibre Type distribution and histochemical properties.

Question 23

Muscle velocity and work output have a(n) ______ relationship.

Answer 23

inverse

Question 24

The inhibitory action caused by what prevents actin-myosin interaction?

Answer 24

troponin

Question 25

Which is the protein complex that is formed when crossbridges make contact with the actin filaments?

Answer 25

actomyosin complex

Question 26

Longer muscle fibres exhibit a higher contractile velocity but a lower force-output capacity

Answer 26

True

Question 27

What splits a phosphate from ATP and releases its stored mechanical energy as it straightens?

Answer 27

myosin