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Flashcards in excitation and contraction Deck (41)
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1

myofibril

- longitudinally with in the muscle fibers
- Z line
- ACH in the neuromuscular junction releases CALCIUM

2

sarcomeres

- composed of this and thick filaments

3

contraction

- causes no change in A BAND
- shortening of I an H BAND

4

I BAND

- ACTIN

5

H ZONE/BAND

- MYOSIN

6

A BAND

- ACTIN and MYOSIN

7

ACH in the neuromuscular junction releases CALCIUM
CALCIUM descends into

- T-tubule

8

sarcolemma

- covering of myofibril

9

sarcoplasmic reticulum

- dumps calcium into the T-tubules

10

T- tubules take calcium into the

- muscles

11

ACTIN

- THIN filaments

12

MYOSIN

- THICK filaments

13

tropomyosin

- covers the binding site
- blocks the myosin head for attachment
- prevents cross linking to actin

14

calcium binds to

- troponin

15

troponin

- functions is to move tropomyosin

16

hydrolysis of ATP causes

- cross bridge to gain energy and affinity for actin
- loss of affinity for actin

17

SARCOPLASMIC RETICULUM

- STORAGE SITE FOR CALCIUM

18

2 ATP's are needed

- to start mechanical contraction

19

ATP split are needed for

- relaxation and contraction

20

skeletal muscle action potential

- SHORT
- causing multiple action potential

21

complete TETANUS is obtained

- when sufficient free calcium is available
- everything is engaged

22

complete tetanus vs rigor mortis

- tons of calcium , actin and myosin are engaged (TETANUS)
- no ATP it doesn't detached (RIGOR MORTIS)
- SAME

23

ABSOLUTE REFRACTORY PERIOD

- is already depolarized
- -70mV
- happening

24

relative refractory period

- going back to normal
- earliest time that can have a new stimulus
- can get new depolarization

25

preload

- load on a muscle in a relaxed state prior to contraction
- causes muscle to STRETCH
- causes muscle to develop PASSIVE TENSION

26

AFTERLOAD

- how much effort to push to get the blood out 100lb
- the HIGHER THE BLOOD PRESSURE the MORE THE LOAD

27

drugs that decrease renin angiotensin aldosterone (CHF)
decrease AFTERLOAD (lowers amount of ischemia, arrhythmias, and death)

- spironolactone
- ACE inhibitors
- beta blocker
- ARB

28

more preload

- more passive tension

29

stretch too much loose (DILATED CARDIOMYOPATHY)
over stretch the actin and myosin filaments
PASSIVE

- FORCE
- cannot generate force of contraction
- causing low EF

30

no stretch

- straight contractility