the functioning of the brain (pack 1)

Question 1

what is a neuron

Answer 1

a specialised cell within the nervous system

Question 2

what is the function of neurons

Answer 2

to communicate with 1000s of other cells at a time in huge networks

Question 3

what are all the parts to a neuron and their function

Answer 3

axon- passes electrons to other regions

dendrites- receives signals from other neurons

cell body- organises and keeps the cell functional

nucleus- houses genetic material

axon hillock- connects cell body to neuron

myelin sheath- increases speed of signal

nodes of Ranvier- allows diffusion of neurons

synapse- forms junctions between other neurons and communication between one neuron and the next take place

Question 4

what are the 3 main elements to communication with the synapse

Answer 4

1. the pre-synaptic neuron where the action potential starts
2. the post-synaptic neuron where the message travels to
3. the tiny space between the two called the synaptic cleft

Question 5

what are all 6 parts to a synapse

Answer 5

1. pre-synaptic neuron
2. neurotransmitters
3. receptors
4. synaptic cleft
5. synaptic vesicle
6. action potential

Question 6

what are the functions of neurotransmitters

Answer 6

neurons make a chain with each other which allows messages to be sent from one part of the brain to another keeping the brain and body working correctly

Question 7

what are neurotransmitters

Answer 7

chemical messengers

Question 8

what is the process that neurotransmitters go through

Answer 8

released from pre-synaptic neuron into cleft after an action potential

they then stimulate the post-synaptic neuron and assist it to create it’s own action potential

Question 9

what are the 3 main neurotransmitters and their functions

Answer 9

serotonin- regulates attention, behaviour and body temp

dopamine- chemical that makes you feel good

noradrenaline- plays a part in fight or flight

Question 10

what are the 4 steps for the process of synaptic transmission

Answer 10

1. Action potential moves down pre-synaptic neuron and causes vesicles filled with neurotransmitter to move closer to terminal membrane
2. vesicle fuses with terminal membrane in process of endocytosis…this causes NT to be released in synaptic cleft
3. NT binds with receptors in post synaptic neuron and the pre-synaptic neuron receptors:
   activation of receptors on post-synaptic increase action potential prob.
   activation of auto-receptors on pre-synaptic causes it to stop releasing NT
4. once NT released into synaptic cleft it is removed via
   reuptake
   broken down (by enzymes)
   diffusion

Question 11

one strength of synaptic transmission as an explanation of how messages move around body

Answer 11

PET scans- objective and reliable so increase scientific credibility
(pet scans do not give microscopic detail on synaptic transmission

Question 12

two weaknesses of synaptic transmission as an explanation of how messages move around body

Answer 12

1. much evidence. has come from animals, can’t generalise, may not be valid as there are differences
   e.g Van Den Oever
2. ignores individual differences as it’s assumed everyone brains work in the same way. BUT some people have different levels of NT that may influence the messages