Muscle Physiology 1-2

Question 1

What are the 4 specific properties of muscle

Answer 1

1. Contractility
2. Excitability
3. Extensibility
4. Elasticity

Question 2

The ability to contract or shorten

Answer 2

Contractility

Question 3

the capacity to receive and respond to stimulus

Answer 3

excitability

Question 4

the ability to be streched

Answer 4

Extensibility

Question 5

The ability to return to original shape after being streched

Answer 5

Elasticity

Question 6

What are the 3 types of muscle

Answer 6

1. Skeletal
2. Smooth
3. Cardiac

Question 7

List the levels of organization of skeletal muscle from outside in.

Answer 7

1. Epimysium
2. Fascicle
3. Perimysium
4. Endomysium
5. sarcolema
6. Muscle fibers

Question 8

What are the 2 types of muscle fibers?

Answer 8

1. Red/Type I/ Slow twich

2. White/ Type II/ Fast twitch

Question 9

The basic contractile unit of striated muscle fibers

Answer 9

Sarcomeres

Question 10

What are the 2 types of myofilaments?

Answer 10

1. Actin (thin)

2. Myosin (thick)

Question 11

Specialized ER found in muscle cells

Answer 11

Sarcoplasmic reticulum (SR)

Question 12

What is the function of SR?

Answer 12

Regulate Calcium storage, release, and reuptake

Question 13

T/F. the SR is bigger in Red muscle

Answer 13

F. Larger in White muscle

Question 14

T/F. Red muscle has more mitochondria than white.

Answer 14

T

Question 15

Allow the PM of the muscle fiber to carry the depolarization of the AP to the interior of the fiber

Answer 15

T-Tubules

Question 16

Junction between a nerve fiber and muscle cell

Answer 16

Neuromuscular junction

Question 17

The diffusion potential level across a memb. that exactly opposes the net diffusion of a particular ion through the memb.

Answer 17

Nerst potential

Question 18

What are the 3 forces that cause diffusion of molecules and ions through a CM?

Answer 18

1. Net diffusion rate
2. Nerst Potential
3. Pressure diff.

Question 19

What is the resting potential fo nerve fibers when not transmitting signals?

Answer 19

-70mV

Question 20

What are the 3 factors that determine resting potential?

Answer 20

1. diffusion of K through the nerve cell memb.
2. diffusion of Na through the nerve cell memb.
3. Contribution of the Na/K pump

Question 21

What allows K to diffuse out of the cell?

Answer 21

K leak channels

Question 22

What allows Na to diffuse out of cell?

Answer 22

Na leak channels

Question 23

T/F. the memb. is far less permeable to Na than K.

Answer 23

T

Question 24

What is the most important contributor to resting potential?

Answer 24

K diffusion

Question 25

How many ions of sodium and potassium does the Na/K pump pump in and out of the cell?

Answer 25

2K ions in

3Na ions out

Question 26

how are nerve signals transmitted?

Answer 26

AP

Question 27

Rapid changes in the memb. potential that spread rapidly along the nerve fiber memb.

Answer 27

AP

Question 28

What are the 3 stages of an AP?

Answer 28

1. Resting
2. depolarizing
3. repolarizing

Question 29

Moment before AP begins

Answer 29

Resting stage

Question 30

Stage of AP where a threshold for the initiation of the AP has been achieved.

Answer 30

Depolarization state

Question 31

During depolarization is the memb. potential rising in the positive or negative direction?

Answer 31

positive

Question 32

How does the massive Na influx occur?

Answer 32

Voltage-Gated sodium channels

Question 33

Stage of AP after the memb. becomes highly permeable to Na ions, and the Na channels begin to close

Answer 33

Repolarization

Question 34

What channels open during the repolarization stage?

Answer 34

voltage gated K channels

Question 35

Re-establishment of the normal negative resting potential

Answer 35

Repolarization

Question 36

What is the Refractory period?

Answer 36

A new AP cannot occur in an excitable fiber as long as the memb. is still depolarized from the preceding AP

Question 37

the period during which an second AP cannot be elicited

Answer 37

Absolute Refractory Period