⭐️ neurons & synaptic transmission✅

Question 1

.what are neurons used for?

Answer 1

a communication system that transmits signals

Question 2

what are the 3 types of neurons?

Answer 2

• sensory neurons
• relay neurons
• motor neurons

Question 3

sensory neurons:

where do they carry messages from and too?

what is there structure like?

Answer 3

from the PNS to the CNS

they have long dendrites and short axons

Question 4

relay neurons:

what two neurons do they connect?

structure?

Answer 4

comments sensory to motor

short dendrites and short axons

Question 5

motor neurons:

what do they connect?

structure?

Answer 5

connects CNS to effectors such as muscles and glands

short dendrites and long axons

Question 6

definition of dendrites

Answer 6

carry impulses from other neurons towards cell body

Question 7

definition of a cell body

Answer 7

surrounds the nucleus which contains DNA

Question 8

definition of an axon

Answer 8

carries impulses way from cell body to the terminals

Question 9

definition of the myelin sheath

Answer 9

fatty layer protecting axon and speed up the transmission of electrical impulses

Question 10

wha are the nodes of ranvier

what do they speed up?

Answer 10

small gaps which break up the MS

they speed up the transitions of impulses by forcing it to jump across the axon.

Question 11

definition of the axon terminals

Answer 11

buttons that communicate with the next neuron in a chain across the gap - this gap is known as a synapse

Question 12

firing of a neuron:

what charge is the neural when its resting?

what charge is it when its activated? what does this do?

Answer 12

negatively changed

positively charged - this creates an electrical immune that travels down the neuron

Question 13

synaptic transmission:
- what is it?

• what is a neurotransmitter?

Answer 13

• process where neighbouring neurons communicate with each other by sending chemical messages across synapses.
• NTs are brain chemicals that are released from synaptic vesicles that relay info across synapses

Question 14

neuron communication:
- what is the gap called which each neuron is separated by?

• how are signals within the neurons transmitted?
• how are signals between the neurons transmitted?
• what are synaptic vesicles?

Answer 14

• synaptic cleft
• electrically
• chemically
• tiny sacs filled with NTs in a synapse

Question 15

neuron communication:
- what is it known as when info is passed as an electrical impulse through an axon?

• how does this reach the next neurone?

Answer 15

• action potential

- it has to jump across the synapse between the pre- synaptic and post- synaptic neurons

Question 15

neuron communication:
- what is it known as when info is passed as an electrical impulse through an axon?

• how does this reach the next neurone?

Answer 15

• action potential

- it has to jump across the synapse between the pre- synaptic and post- synaptic neurons

Question 16

synaptic transmission:

what are excitatory neurotransmitters?

what are inhibitory neurotransmitters?

Answer 16

• ‘on switches’, cause a positive charge

- ‘off switches’, cause a negative charge

Question 17

synaptic transmission:

• where are vesicles only on?
• what are receptors only on?
• why is this the case?

Answer 17

• the pre-synaptic neuron
• the post synaptic neuron
• it only passes one way bc there are no receptors on the pre-syn. so it cant go back

Question 18

what is summation?

what happens if the net affect on the post- syn. is inhibitory?

what happens if the net affect on the post- syn. is excitatory?

what does this mean about the action potential?

Answer 18

the process that decides whether a post synaptic neuron is fired or not.

the neuron is less likely to fire

the neuron is more likely to fire

is only triggered if the sum of the excitatory and inhibitory signals reaches the threshold.