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Flashcards in How Nerves Work 2 Deck (21):
1

Do hormones or nerves produce faster responses?

Nerves

2

How is the electrical signal of nerves made?

Through the three membrane potentials:

Resting membrane potential

Graded membrane potential

Action potential

3

What is the resting membrane potential responsible for?

Keeps cells ready to respond

4

What is the graded potential responsible for?

Determines whether an action potential should be fired

5

What is the action potential responsible for?

Transmits signals over long distances

6

What is the voltage of the inside of a cell compared to the outside?

-70mV

7

What is responsible for the inside of a cell being -70mV compared to the outside?

Leaky K+ channels

8

What is the equilbrium potential?

Membrane potential at which the elctrical gradient is exactly equal and opposite to the concentration gradient

9

The Nernst equation predicts the equilbrium potential, what does this look like?

10

What is 0K in oC?

-273oC

11

What is the equilbrium potential for K+?

-90mV

12

How does the blood brain barrier protect the brain from changes in ion concentration?

Cappilaries are especially tight

This is due to astrocytes and tight junctions

13

What are the typical concentrations of important ions in and outside a cell?

K+ greater inside

Na+ greater outside

Cl- greater outside

14

What is the equilbrium potential for Na+?

+50mV

15

What is the equilbrium potential for Cl-?

-75mV

16

The goldman equation predicts the equilbrium potential for several ions, what does this look like?

17

Why is the normal resting membrane potential (RMP) -70mV?

Electrogenic nature of the Na+/K+ pump (3 Na+ out and 2 K+ in)

Lrge intracellular negatively charged molecules

18

What does depolarising mean?

Takes the cell towards 0V

19

What does overshoot mean?

Polarises in the opposite direction

20

What does repolarise mean?

Polarise in original direction

21

What does hyperpolarise mean?

Greater polarisation in the same direction