Muscle Structure & Function

Question 1

Compare and contrast slow vs. fast muscle fibers

Answer 1

Slow has more mitochondria, more myoglobin, Type I myosin, slower cross-linking, is more efficient with atp production, less Ca++ depletion, and more O2.
Fast has more extensive SR

Question 2

List the A, I bands. Z line, and H zone

Answer 2

A-myosin, I-actin, Z line-sarcomere middle of I, H band is myosin zone only decreases with contraction

Question 3

What triggers contraction of muscle

Answer 3

Ca++ binding to troponin complex

Question 4

what part of the sarcoplasmic reticulum contains Ca++

Answer 4

terminal cisternae

Question 5

what would be the result of destroying a nerve?

Answer 5

flaccid paralysis

Question 6

How does Botox (botulism toxin) work

Answer 6

it blocks the release of ACh

Question 7

what is rhabdomyolysis

Answer 7

myoglobin in urine, side effect would be damage to kidney with free myoglobin fragments

Question 8

what causes tetany

Answer 8

<50% calcium, nerves try compensating for not being able to contract

Question 9

tetanus?

Answer 9

a poison prevents inhibitory of ACh, so their is a hypersecretion and therefore prolonged contraction

Question 10

Slow muscle fibers would stain what color? Fast stain this color?

Answer 10

WHITE for slow, Dark for Fast

Question 11

Eye movements would be an example of slow or fast muscle fibers?

Answer 11

FAST

Question 12

What helps myosin release actin after each power stroke in order to “reset” itself

Answer 12

ATP

Question 13

what does length/tension relationship for muscle look like on graph?

Answer 13

Shorter length=greater tension as when contracting; longer length=less tension like when elbow is fully extended trying to do bicep curl