Neuromuscular Junction Flashcards

0
Q

In order for an acetylcholine-gated ion channel to open, how many Ach molecules need to attach to its alpha subunits

A

Two

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1
Q

Anchored to the pre synaptic membrane and associated with synaptic vesicles to which they are tethered by short filaments

A

Dense bars

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2
Q

What represents the first thing that happens after Ach binds to the ligand gated channels in the sarcolemma?

A

An end plate potential is created on the muscle fiber

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3
Q

A groove in the surface of the sarcolemma in which the axon terminal makes contact with the sarcolemma

A

Synaptic gutter

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4
Q

A gap between the axolemma of the axon terminal and the sarcolemma of the innervates muscle fiber

A

Synaptic cleft (20-30nm wide)

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5
Q

Sarcolemma of the skeletal muscle has what kind of ion channels?

A

Acetylcholine gated ion channel

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6
Q

The vesicles for acetylcholine are transported to the axon terminal from where?

A

The Golgi

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7
Q

Where is acetylcholine synthesized?

A

In the cytosol of the nerve axon terminal

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8
Q

Describe what happens when the action potential arrives at the terminus of the axon

A

The voltage gated calcium channels open and calcium ions enter the axon terminus.

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9
Q

After an end plate potential is created, the action potential on the sarcolemma moves down the T tubules activating which channels?

A

Voltage gated Dihydropyridine channels

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10
Q

Dihydropyridine channels activate which receptors that allow calcium to flow into the cytosol?

A

Ryanodine receptors.

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11
Q

Once calcium ions are released in to the cytosol, they bind to (?) in the sarcolemma causing the “sliding filament” mechanism

A

Troponin!

Fun fact: ER draw troponin levels to help indicate if someone had an MI. These are time dependent and the higher the level the more likely someone had an MI or tissue damage.

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