Week 13: (C) Coupling and Skeletal Muscle Contraction Flashcards

1
Q

What does an excitation contraction trigger?

A

triggers an increase in Ca2+ concentration

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2
Q

What is excitation contraction also known as?

A

E-C coupling

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3
Q

What is the plasma membrane also called?

A

sarcolemma

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4
Q

What is the sarcolemma?

A

display invaginations that extend from surface of membrane to muscle cell
membrane of muscle fibre

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5
Q

What are these tubules called?

A

Transverse tubules (T tubules)

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6
Q

What muscle fibres has T tubules?

A

skeletal & cardiac

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7
Q

Where do the T tubules penetrate the muscle cells?

A

2 points in each sarcomere at junction of A and I bands

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8
Q

What do the T tubules associate with?

A

2 cistermma

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9
Q

What is the cistermma?

A

specialised regions of the sarcoplasmic rectilium

muscles version of ER

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10
Q

What organelle stores Ca2+ ions?

A

Sarcoplasmic rectilium

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11
Q

What is the TRIAD?

A

The combination of the t-tubule with the 2 cistermma

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12
Q

What is depolarised in the TRIAD?

A

T-tubule membrane

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13
Q

Where is Ca2+ released from?

A

Sarcoplasmic rectilium at the TRIAD

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14
Q

What organelle has the L-type Ca2+ channels?

A

T-tubules

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15
Q

What is an L-type Ca2+ channel?

A

They are a tetrad
cluster of 4
voltage gated

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16
Q

why do we have T-tubules?

A

need to covert a chemical signal to a physical one
provide a means of rapidly transmitting the action potential from the surface into the central portion of the muscle fibre

17
Q

What opens the L-type Ca2+ channels?

A

depolarisation

18
Q

What is DHP?

A

Another name for the L-type Ca2+ channel

19
Q

What does depolarisation of the membrane do to DHP?

A

confo change

20
Q

What are the effects of the conformational change of L-type Ca2+ channel?

A

confo change allows Ca2+ to enter

A confo change in a another channel called Ca2+ release channel

21
Q

Where is the Ca2+ release channel located?

A

SR

22
Q

What can inhibit the Ca2+ release channel?

A

ryanodine& caffine

23
Q

How do the L-type and release channel attach?

A

release channels face the T tubules

The foot of the release channel is close to one of the L-type

24
Q

What happens once coupling occurs between receptors?

A

Ca2+ released into the cytosol