Physiology Quiz 3 (2/2)

Question 0

Motor unit

Answer 0

A single motor efferent nerve and the muscle cells it innervates

Question 1

Efferent

Answer 1

Carry info away from CNS

Question 2

Small motor units = _______ motor activity

Answer 2

Fine

Question 3

Large motor units= ______ motor activity

Answer 3

Gross

Question 4

What part of the body has the smallest motor units?

Answer 4

Muscles controlling the eye (4 muscle cells/1 motor efferent)

Question 5

What part of the body has the largest motor units?

Answer 5

Some of he trunk musculature (1000 muscle cells/1 motor efferent)

Question 6

Concentric muscle activity

Answer 6

Development of force by the muscle as it shortens

Question 7

Example of concentric muscle activity

Answer 7

Bringing the weight up during a bicep curl

Question 8

Eccentric muscle activity

Answer 8

Development of force by the muscle as it lengthens

Question 9

Example of eccentric muscle activity

Answer 9

Lowering the weight during a bicep curl

Question 10

What type of muscle activity uses more energy? (Concentric or eccentric)

Answer 10

Concentric

Question 11

Which type of muscle activity is easier to learn motor control of? (Concentric or eccentric)

Answer 11

Concentric

Question 12

DOMS

Answer 12

Delayed onset muscle soreness

Question 13

When does DOMS peak?

Answer 13

48-72 hours after activity

Question 14

What is DOMS caused by?

Answer 14

Repair of microtears in series elastic element (SEE) mostly caused by eccentric activity (less often with concentric). This microtearing causes inflammation, swelling, pain, and scarring

Question 15

Elasticity

Answer 15

Shortens and returns to original configuration

Question 16

Plasticity

Answer 16

Stretches, but it will reach a certain point where it will not return to original configuration

Question 17

Plasticity range

Answer 17

Point a series elastic element stretches to where it will still return to original configuration; any further and it will not return to original configuration

Question 18

Is plasticity good?

Answer 18

Yes, it can help with flexibility

Question 19

Series elastic element

Answer 19

Structures that have the property of elasticity

• tendons
• connective tissue sheaths or muscle and myofibrils
• crossbridges

Question 20

How is force transmitted in concentric activity?

Answer 20

It will absorb some force and transmit the rest (think about rubber band pulling water bottle water bottle)

Question 21

How force is transmitted during eccentric activity

Answer 21

Develops force because it is undergoing a stretch force and thereby adds to the force developed eccentrically

Question 22

Source of force in concentric activity

Answer 22

Crossbridges

Question 23

Source of force in eccentric activity

Answer 23

Crossbridge activity
SEE recoil (mostly this one)

Question 24

Which type of muscle activity uses less energy (eccentric or concentric)

Answer 24

Eccentric

Question 25

Unorganized scar

Answer 25

Random laying down of collagen fibrils as a scar forms
Decreases ROM
not desirable

Question 26

Organized scar

Answer 26

Laying down of collagen fibrils in an organized and controlled manner
Less loss of ROM
Stretching helps develop this

Question 27

Isometric contraction

Answer 27

As muscle develops force, distance between origin and insertion does not change (fibers still shorten)

Question 28

Example of isometric contraction

Answer 28

Wall sit

Question 29

Isotonic contraction

Answer 29

Muscle changing length but maintaining same force throughout movement

Question 30

Isokinetic contraction

Answer 30

No change in velocity of movement
Likely to see change in length and force as contraction proceeds
Done on machine with a set degrees/sec