Neurons and neurotransmission

Question 1

Where are sensory neurons found and what do they do?

Answer 1

They are found in receptors such as the eyes, ears, tongue and skin and carry nerve impulses to the spinal cord and brain. When these impulses reach the brain they are translated into sensations such as vision, hearing and taste. Some stop at the spinal cord to allow for quick reflexes.

Question 2

Where are relay neurons found and what do they do?

Answer 2

Found in the brain and spinal cord and allow sensory and motor neurons to communicate

Question 3

Where are motor neurons found and what do they do?

Answer 3

Found in the CNS and control muscle movements by releasing neurotransmitters that bind to the receptors on muscles to trigger a response which causes movement.

Question 4

What is synaptic transmission?

Answer 4

How electrical impulses are passed between neurons in your brain and nervous system

Question 5

Describe the process of synaptic transmission

Answer 5

1. Electrical impulse travels down neuron’s axon
2. When it gets to the end it hits the axon terminal at the pre-synaptic cell
3. At the axon terminal, synaptic vesicles containing neurotransmitters are released into the synaptic clef when Ca2+ enter.
4. The neurotransmitters travel across the synaptic cleft and bind to receptors on the post synaptic cell
5. The neurotransmitters can either excite or inhibit the post synaptic cell
   - Excitatory neurotransmitters: e.g noradrenaline makes the next neuron more likely to fire resulting in EPSP (excitatory post-synaptic potential)
   - Inhibitory neurotransmitters: e.g GABA makes it less likely to fire resulting in IPSP (inhibitory post-synaptic potential)