CNS - neurones, NTs and synapses

Question 1

what are ions

Answer 1

electrically charged chemicals

Question 2

example of positive ion

Answer 2

sodium (Na+)

Question 3

example of negative ion

Answer 3

chloride (Cl-)

Question 4

what are the charges inside and out of a neurone at rest

Answer 4

negative on inside
positive on outside

Question 5

resting potential of a neurone

Answer 5

-70mV

Question 6

what is an action potential

Answer 6

a spike in electric charge in an axon caused by sodium ions crossing the cell membrane - created by depolarising current

Question 7

how does a stimulus cause an action potential

Answer 7

• causes resting potential to move towards being more positive
• reaches threshold of -55mV so ion channels open
• positive ions diffuse in down electrochemical gradient
• neurone grows more positive and depolarised

Question 8

what is the result of depolarisation and action potential

Answer 8

electrical impulse fires across neurone away from cell body and towards to axon terminal then returns to resting

Question 9

how does synaptic transmission work

Answer 9

• presynaptic neurone excited by action potential
• vesicles containing NT fuse with presynaptic membrane
• NTs enter synaptic cleft
• they bind to receptors on postsynaptic neurone, this activates the next neurone
• some NTs then leave the cleft by diffusion, reuptake back into presynaptic neurone or are broken down by enymes

Question 10

examples of NTs

Answer 10

dopamine
glutamate
serotonin

Question 11

dopamine

Answer 11

pleasure and addiction
influences motivation and reward pathway

high/low levels can cause SZ

Question 12

glutamate

Answer 12

cognitive function
memory and learning

excess can cause cell death, then alzheimers/strokes/seizures

Question 13

serotonin

Answer 13

happiness and mood
more serotonin, less depressed

Question 14

what makes up the CNS

Answer 14

brain + spinal cord

Question 15

frontal lobe

Answer 15

at the front
thinking/problem solving

Question 16

parietal lobe

Answer 16

at the top
perception

Question 17

temporal lobe

Answer 17

at the bottom
memory/language

Question 18

occipital lobe

Answer 18

at the back
visual processing

Question 19

cerebellum

Answer 19

coordination

Question 20

brain stem

Answer 20

regulates heart rate and body temperature

Question 21

limbic system

Answer 21

hypothalamus
hippocampus
amygdala

Question 22

hypothalamus

Answer 22

homeostasis
regulates hormones and emotions

Question 23

hippocampus

Answer 23

converts STM to LTM

Question 24

left amygdala

Answer 24

motivation and reward

Question 25

right amygdala

Answer 25

fear conditioning