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Flashcards in Dr. KO lecture 2 Deck (17)
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1

Electrical signals (receptor potential, synaptic potential and action potential) are all caused by transient changes in the (blank), that drives the electrical potential across the plasma membrane away of its resting condition.

current flow into and out of the membrane

2

Stimuli that elicit an action potential are (blank)

suprathreshold

3

Action potentials are (nearly) (blank) of the stimulus.

independent

4

WHen you inject a negative charge into a cell you will get what?
how bout a positive?

hypepolarization
depolarization

5

The resting potential is set by the K+ (blank) channels.

leak

6

When s the refractory period?

From peak to resting potential

7

(blank) affects the nervous system in such a way as to prevent the propagation of nerve impulses. 

Tetrodotoxin

8

Describe difference between absolute refractory period and relative refractory period

Absolute; all Na+ channels are close, nothing can activate them to create action potential
Relative, some Na+ channels are closed and others are open, a very strong stimulus can create action potential

9

premature contraction in the heart is an example of a stimulus being so big it messes with allows the (blank) to create an action potential.

relative refractory

10

What size cells conduct faster?

larger cells

11

The rate of conduction depends on?

number of open Na channels, amount of influx of Na, cell size (larger is better),

12

The speed of conduction depends on?

1. Electrical resistance of the plasma membrane to current flow.

2. The resistance of the longitudinal path down the inside of the fiber.

13

What can reduce resistance in an axon?

increased diameter

14

In Sequential activation of Neuromuscular Transmission (neuromuscular junction) what happens at the presynaptic cleft.

depolarization induces calcium channels to open which makes ACh get released into synaptic cleft

15

In Sequential activation of Neuromuscular Transmission (neuromuscular junction) what happens at the postsynaptic cleft.

Ach binds to cation channels which create deplorazation and allows Na channels to open and create more depolarization.

16

In Sequential activation of Neuromuscular Transmission (neuromuscular junction) how does calcium get released in the postsynpatic terminal?

Depolarization of muscle cell activates Ca2+ channels which induces CICR (calcium induced calcium release) from ER

17

What do these mess with:
Curare
a-bungarotoxin
Myasthenia gravis-tx

acetylcholine release