Lecture 21: Bioelectricity, Membrane Potential Flashcards Preview

HUBS 191💃✨ > Lecture 21: Bioelectricity, Membrane Potential > Flashcards

Flashcards in Lecture 21: Bioelectricity, Membrane Potential Deck (16):
1

What was Galvani's contribution to Bio-electricity?

- He experimented with frog legs & found that they could twitch

2

A cell is like a battery in that....

- The outside of the cell has positive charges, and the inside has negative charges
- The membrane separates electrically charged molecules

3

There are two types of ions (electrolytes):

- Cations & Anions

4

Most important cations:

- Sodium, Potassium, Calcium

5

Most important anions:

- Chloride, Bicarbonate

6

Bio-Electricity of neutrons mainly rely on:

- Sodium & Potassium

7

How do neurons control their current flow?

- Ion channels
- Closed = off, Open = on
- Allow ions to move past cell membrane (ion current)

8

How is the membrane potential maintained?

- Sodium Potassium Pump
- 3 x Na OUT for 2 x K+ IN

9

Difference between pumps and channels:

- Pumps = against gradient (energy consuming)
- Channels = down gradients

10

A membrane potential varies by:

- It's size
- The time

11

The membrane potential changes if channels...

- Are open (and then shut)

12

When depolarisation occurs, ____ charges move in, and _____ channels are open.

- Positive
- Sodium
E.g -60mV

13

When a membrane potential is depolarised then hyperpolarized, ____ channels open, and _____ charges move out.

- Potassium
- Positive
- eg -80mV

14

Depolarisation is _____tory whereas hyperpolarisation is ______tory.

- Excitatory
- Inhibitory

15

Types of potential:

- Resting
- Local
- Threshold
- Action

16

What is electricity?

- Particles with different charges + or -
- Separation of change = energy stored = potential energy (water dam)
- Energy released when charges / current flows = electricity at work