Exam 3 Review Session MUSCLES

Question 1

Why are muscles multinucleated

Answer 1

cuz they’re fused togther in childhoood

Question 2

What are within myofibrils

Answer 2

myofilaments

Question 3

What are myofilaments composed of

Answer 3

myosin and actosin

Question 4

what is the sarcolemma

Answer 4

cell membrane of muscle cell

Question 5

what is the sarcoplasm

Answer 5

cytosol of muscle cell

Question 6

What is the overlap of actin and myosin

Answer 6

A band

Question 7

Only the actin

Answer 7

I band

Question 8

Where only myosin

Answer 8

H band

Question 9

Z disc to another

Answer 9

sarcomere

Question 10

How to descripe what happens in a muscle cell

Answer 10

“sliding past each other” “ distance between z disks is reduced” “A band never changes in length”

Question 11

Does the I band shorten

Answer 11

Yes, H band too.

Question 12

HOw is muscel contraction done

Answer 12

ACh released to bind a nicotinic ACh receptor, opens ligan gated channels, Na+ diffuses in depolarizing: action potential induced

Action potential conducts along transverse tubules, action potential opens voltage-gated Ca2+ channels

Ca2+ release channels in SR open, Ca2+ diffuse out into sarcoplasm

Ca2+ binds to troponin, stimulating contraction

Question 13

What is the cross-bridge cycle

Answer 13

1. ATP bound to myosin head, no connection of actin and myosin: Up position.
2. Head back, ADP and Pi, no connection, then Connection of actin and myosin
3. POWER STROKE
4. New ATP bound to myosin head in the up position

Question 14

List the phases of ATP synthesis in running

Answer 14

Aerobic respiration using stored oxygen in myoglobin
Phosphagen system
Glycogen-lactate system (aerobic ferm)
Aerobic respiration supported by cardiopulmonary function