neurons and neurotransmission

Question 1

sensory neurons

Answer 1

• carry nerve impulses from sensory receptors (eyes, ears, tongue, skin etc.) to the cns
• at the brain they’re translated into sensations (vision, hearing, taste, touch)
• some neurons will stop at the spinal cord for simple reflex actions

Question 2

relay neurons

Answer 2

• found between sensory input and motor output/response
• they are found in the brain and spinal cord
• they allow sensory and motor neurons to communicate

Question 3

motor neurons

Answer 3

• found in the cns, carrying messages from it to muscles around the body
• they control all muscle movement
• when stimulated they release neurotransmitters which bind to muscle receptors to create movement

Question 4

dendrites

Answer 4

• receive signals from other neurons or sensory receptor cells
• typically connected to the cell body

Question 5

axon

Answer 5

long slender fibre that carries nerve impulses from the cell body to the axon terminal

Question 6

myelin sheath

Answer 6

surrounds most axons (not in relay neurons), insulating them so electrical impulses travel faster

Question 7

axon terminal

Answer 7

connects a neurons to others or to organs directly via synaptic transmission

Question 8

the process of synaptic transmission

Answer 8

1. info is passed down the axon as an action potential
2. at the end of the axon it must pass the synaptic gap between the pre and post synaptic vesicles
3. when it reaches the synaptic vesicles in the axon terminal they release neurotransmitters
4. the neurotransmitters carry the message across the synaptic gap which bind to receptors on the post synaptic cell
5. when activated the receptors produce either inhibitory or excitatory effects on post synaptic cell

Question 9

inhibitory neurotransmitters

Answer 9

• e.g. GABA
• make the post synaptic cell less likely to fire
• they prevent the chemical message from being passed down further
• if they bind to the post synaptic receptors it results in an inhibitory post synaptic potential

Question 10

excitatory neurotransmitters

Answer 10

• e.g. noradrenaline
• make the post synaptic cell more likely to fire
  -they excite the neuron so it fires off the message, the message continues to be passed on to the next cell
• if they bond to post synaptic receptors it causes an electrical charge in the cell membrane resulting in an excitatory post synaptic potential