Excitation Coupling Relaxation

Question 1

Excitation:

Answer 1

Turns the event on

Question 2

1. Initiate action potential on __

Answer 2

sarcolemma

Question 3

2. Action potential propagates ___

Answer 3

onto surface of sarcolemma

Question 4

3. Action potential is ____

Answer 4

contiguous conduction on sarcolemma

Question 5

4. Action potential propagrates down into

Answer 5

T-tubules

Question 6

5. Upon propagating down into t tubules, AP stimulates

Answer 6

Dihdydropyridine receptors

Question 7

6. After dihydropyradine receptors, ____

Answer 7

Ryanodine receptors on lateral sacs of SR are stimulated

Question 8

7. Ryanodine Receptors are ___channels

Answer 8

calcium channels

Question 9

8. calcium channels___ resulting in___ from ___ to____

Answer 9

calcium channels open resulting in the diffusion of calcium from the SR to the sarcoplasm

Question 10

9. Once in the SR, calcium ___
   causing____
   and ultimately

Answer 10

interacts with troponin causing a conformational change, ultimately moving tropomyosin

Question 11

10. The _____ are exposed

Answer 11

myosin binding sites on the actin filament are now exposed

Question 12

Excitation EVENT!

Answer 12

A. AP propagates onto the surface of the sarcolemma (one stimulus producing one end plate potential)
a. AP is the same in the sarcolemma as in the neouron, except the AP is contiguous conduction on the sarcolemma
B. AP penetrates cell bypassing into the T-tubules (interior of the cell) and stimulates the Dihydropyridine receptors
C. Next stimulation of the Ryanodine receptors (Ca – channels)on the lateral sacks of the sarcoplasmic reticulum
D. Ca channels open resulting in the diffusion of calcium from the SR to the sarcoplasm
E. Once in the sarcoplasm Ca then interacts with troponin causing a conformational change, ultimately moving tropomyosin
a. The myosin binding sites on the actin filament are now exposed

Question 13

Coupling

Answer 13

formation of an actomyosin cross bridge

actin and myosin have linked up

Question 14

The sliding filament theory
a-band
I band
H zone

Answer 14

HI=change with contractions
Hzone shortens
I band shortens
A band says same width

Question 15

Relaxation is achieved by

Answer 15

pumping calcium back into the SR