synapse& brain chemicals

Question 1

what is an EEG?

Answer 1

consists of 21 electrodes placed on the head, which records brain activity. Each electrode has a number, odd is placed on the left of the brain, even is placed on the right of the brain

Question 2

what are the normal patterns recorded on an EEG?

Answer 2

alpha, beta, delta and theta

Question 3

what is the normal pattern for alpha?

Answer 3

frequency of 8-13 Hz, amps of 20-200
presents itself when awake with eyes closed

Question 4

what is the normal pattern for beta?

Answer 4

frequency of 13-30 Hz, amps of 5-10
presents itself when awake

Question 5

what is the normal pattern for delta?

Answer 5

frequency of 1-5 Hz, amps of 20-200
presents itself when sleeping

Question 6

what is the normal pattern for theta?

Answer 6

frequency of 4-8 Hz, amps of 10
presents itself in young children and adults in deep sleep

Question 7

what are the steps at the synapse junction?

Answer 7

1) Action potential/ nerve impulse arrives
2) The membrane depolarises and Ca2+ ions enter the neurone
3) Calcium ions cause vesicles to fuse with the presynaptic membrane
4)Neurotransmitters is released into synaptic cleft + begin to diffuse
5)Neurotransmitters bind with receptors on the postsynaptic membrane+ Na+ channels open
6) Postsynaptic membrane depolarises and initiates an action potential
7) Neurotransmitter will be taken up by the presynaptic membrane or be broken down by enzymes at the postsynaptic membrane- causes Na+ channels to close