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Flashcards in Contraction of the muscle Fiber Deck (47)
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1

The 3 structures that are directly controlling the muscle contraction

Muscle
Nerve
Synapse

2

Theory stating that muscle contraction is based on shortening of sarcomeres throughout the skeletal muscle. Because sarcomeres are end to end, all the way down the length of the skeletal muscle cell, the muscle cell shortens too.

Huxley's Sliding Filament Theory

3

Huxley's Sliding Filament Theory predicts that thick and thin filaments must overlap and slide past one another. Greater overlap = shorter or longer muscle?

Shorter Muscle

4

Contractile element that is made of myosin that has hinged tail and 2 heads which are capable of flexing

Thick Filament

5

What two binding sites are on the heads of myosin?

ATP and Actin binding sites

6

Name the 3 components of thin filament

Actin
Tropomyosin
Troponin Complex

7

There is a binding site on the actin molecules for

myosin

8

Two additional things that are necessary for contraction to occur

Calcium Ions
ATP

9

When a muscle is relaxed, is there maximal or minimal filament overlap?

Is there action potential from the nerve?

Minimal

No.

10

"Activated" myosin heads are holding...

ADP and inorganic phosphate after hydrolization from ATP

11

Is the ATP kinetic or potential energy?

Potential

12

Is there Ca in the cytoplasm surrounding microfibrils?

No

13

Where does the Calcium come from?

Terminal cisternae of the sarcolplasmic reticulum

14

What causes the calclium to enter the cytoplasm and surround the myofibrils?

Action potential along the nerve

15

What does Ca bind with in the myofibril?

Troponin

16

What happens to the troponin once Ca binds with it?

It changes shape

17

What is troponin attached to?

Tropomyosin

18

What forms when the myosin (charged) binds to actin (thick and thin filament of myosin head binds to actin)

Cross Bridge Attachment

19

Flexion of myosin head an tail that pulls thin filament along after cross bridge attachment

Power Stroke

20

What happens when the power stroke goes on the entire sarcomere?

Sarcomere Shortening

21

What occurs next, a process that requires ATP binding to the myosin head?

Cross Bridge Detachment

22

Where does ATP come from?

Cytoplasm

23

What cleaves the ATP into ADP and inorganic phosphate?

Myosin ATPase

24

What does cleaving of ATP into ADP by myosin ATPase achieve?

Storage of the potential energy in the myosin head for next cross bridge

25

What if there is no more contraction/action potential to occur?

Returns to relaxed state

26

What happens to Ca and ATP if there is no more contraction to occur

Calcium goes to terminal cysternae
ATP be bound to myosin head

27

Which step of sarcomere shortening actually uses ATP?

Power stroke

28

Structure that tells the muscle what to do and when to do it

Motor nerve

29

Axon of nerve comes from spinal chord and expands into three

terminal boutons

30

Terminal bouton contains these, which are contained within it

Synaptic Vesicles