Neuromuscular Physiology Flashcards Preview

► Med Misc 44 > Neuromuscular Physiology > Flashcards

Flashcards in Neuromuscular Physiology Deck (110)
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1

Motor Neurons to skeletal muscle originate where?

Anterior (ventral) horn

2

Sensory neurons from skeletal muscle carry action potentials to the spinal cord via the what?

Dosal Horn

3

Motor neurons are what type of fibers?

A=Alpha

4

A-Alpha fibers are the ___, most heavily ___ fibers, thus have the ____ conduction velocity

Largest

Mylinated 

fastest

5

Just to see a picture

Nothing to know just look at pic

6

Look at the cleft

know and understand the parts

 

7

Release of ACh from the nerve terminal:

an ation potential travels along the motor nerve axon and ultimately invades the ______ nerve terminal

Presynaptic

8

Release of ACh from the nerve terminal:

Depolarization of the presynaptic nerve teminal causes voltage-gated ____ channels to open.

Ca++

9

Release of ACh from the nerve terminal:

Ca++ difuses down the concentration gradient _____ the nerve terminal

into

10

Release of ACh from the nerve terminal:

inside the nerve terminal Ca++ causes ____ ____ vesicles to fuse with the nerve cell membrane and open to the exterior. 

release pool

11

Release of ACh from the nerve terminal:

ACh spills out into the synaptic cleft called ______.

Exocytosis

12

Release of ACh from the nerve terminal:

just a picture for reference. Notice Ca++ in and teh release of ACh

 

13

Release of ACh from the nerve terminal:

The presynaptic nicotinic receptor responds to ACh in the cleft by how? what is this also known as?

by increasing the synthesis of ACh and mobilization of ACh-containing vessicles (storage pools) know as positive feedback

14

Release of ACh from the nerve terminal:

what is the purpose of the positive feedback system?

prevents the depletion of ACh at the NMJ and also accounts for the phenomenon of fade seen with nondepolorizing MR (and Phase II block w/ SCh)

15

Release of ACh from the nerve terminal:

again notice the presynaptic Nicotinic receptors. the are the positive feedback system

 

16

Events at the POSTsynaptic membrane:

ACh combines with nicotinic ACh receptors (nAChR) on the postsynaptic membrane. When _____ Alpha subunits or the nicotinic receptor are occupied the ACh. The ion channel snaps open

Both

17

Events at the POSTsynaptic membrane:

ACh combines with nicotinic ACh receptors (nAChR) on the postsynaptic membrane. When _____ Alpha subunits or the nicotinic receptor are occupied the ACh. The ion channel snaps open and the ions ___ and ____ diffuse into the cell and the ion ___ diffuses out of the cell into the extracellular space?

Ca++ and Na+

K+

18

Events at the POSTsynaptic membrane:

notice the binding if ACh and the influx of Ca++ and Na+ and the Efflux of K+

 

19

Events at the POSTsynaptic membrane:

the diffusion of the 3 ions (Ca++, Na+, and K+) through the channel causes the motor end-plate to ______.

Depolarize.

 

20

Termination of Neurotransmitter Action:

________ breaks down ACh.

Acetycholinesterase

21

Termination of Neurotransmitter Action:

Acetylcholinesterase in also called?

true

specific

genuine

type I

22

Termination of Neurotransmitter Action:

Acetylcholinesterase breaks down ACh to ____ and ___

Choline and Acetate

23

Termination of Neurotransmitter Action:

the breakdown of ACh into choline and actate by acetylcholinesterase occurs by what?

hydrolysis

24

Termination of Neurotransmitter Action:

the ____ is transported back into the nerve terminal where it is used to re-synthesize ACh

Choline

25

Termination of Neurotransmitter Action:

Picture to help. 

Notice the termination and breakdown of the ACh

 

26

Postsynaptic Receptors and Channels:

Note 2 of the 5 subunits are identical.

AKA the Alpha subunits

 

27

Postsynaptic Receptors and Channels:

An ACh molecule must attach to each of these 2 identical subunits where the nicotinic receptors are located in order to ____ the channel

open

28

Postsynaptic Receptors and Channels:

stated another way: ___ ACh molecules are needed to open each nicotinic ACh receptor?

2

29

Postsynaptic Receptors and Channels:

Acetylcholinesterase is anchored to the ______ surface of the membrane

External (extracellular)

30

Nondepolarizing block:

Nondepolarizing agents are ______ _______

compettive inhibitors

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