Nervous System Flashcards Preview

HAP1 Mid Sem - LO3 - Proccesses > Nervous System > Flashcards

Flashcards in Nervous System Deck (11):
1

Neuron function

Irritability - able to respond to stimuli
Conductivity - able to transmit an impulse

2

Resting membrane potential

Inside is potassium,
Outside is sodium
Plasma membrane of neuron is at rest (polarised)
Slightly more negative inside than outside

3

Importance of resting membrane

Allows generation and conduction of nerve impulses along an axon

4

Starting a nerve impulse - 5 steps

1. Different stimuli excite neurons to become active and produce an impulse
2. Permeability of the membrane alters
3. Sodium rushes into cell
4. Inside cell becomes more positive than outside = depolarisation
5. Depolarisation generates action potential over the entire axon

5

Action potential - 3 steps

1. Membrane becomes impermeable to sodium but permeable to potassium
2. Potassium rushes out, whilst sodium stays in = repolarisation
3. Sodium-Potassium pump restores original configuration

6

Nerve Impulse propogation

Impulses travel faster with myelin sheath
Impulses jump from node to node
This is called saltatory conduction

7

Synapse events - 3 steps

1. Neurotransmitter is released from axon's terminal
2. Dendrites on other axon has receptors that are stimulated by neurotransmitter
3. Action potential is generated

8

Sympathetic movement

Heart rate increases
Gut activity decreases
"Fight, fright, flight"

9

Parasympathetic movement

Gut activity increases
Heart rate decreases
'Rest and digest'

10

Axons

Conduct impulses away from cell body

11

Dendrites

Conduct impulses towards cell body