L01: Neurons and Synapses

Question 1

What is the CNS

Answer 1

brain and the spinal cord

Question 2

What is the PNS?

Answer 2

All the neurones that connects the the CNS to the other tissues of the body

Question 3

What is the NS made up of

Answer 3

Neurons and Glial cells

Question 4

What are glial cells?

Answer 4

Provide metabolic and physical support to neurone

Question 5

What is a neurone

Answer 5

Specialised cell that is adapted to readily carry nerve impulses (electrochemical change) from one part of the body to another

Question 6

What are sensory neurones?

Answer 6

Afferent neurones: carry nerve impulses from receptors (special sensory organs, skin etc.) to the CNS

Question 7

What are motor neurones ?

Answer 7

Carry nerve impulses from the CNS to effector organs

Question 8

What is the role of the Soma in the neurone

Answer 8

The cell body => contains the cells organelles such as nucleus and RER- production of proteins and neurotransmitters

Question 9

What are dendrons?

Answer 9

• Extensions of the cell body which future divide into dendrites (smaller branched fibres)
• Carries nerve impulses to the cell body

Question 10

What are axons

Answer 10

• Single, long fibres that carry nerve impulses away from the cell body

Question 11

What is myelin and myelination + role

Answer 11

• Myelin sheath wraps around axons
• its made up of Schwann cells - protect axon and provide electrical support
• increases the speed of conduction of nerve impulses

Question 12

What are nodes of Ranvier

Answer 12

Gaps between Schwann cells where there’s no myelin, allows for saltatory conduction

Question 13

Why must neurone activity be coordinated?

Answer 13

As they link together to convey messages from the brain to all over the body, covering large distances

Question 14

Energy change at the synapse

Answer 14

• The synapse converts the electrical impulse of an AP into a chemical message that is transmitted across the synaptic cleft
• This chemical then starts an AP in the next neurone

Question 15

What is the structure of a synapse and how is info transmitted?

Answer 15

• Transmits info via neurotransmitter
• Presynaptic neurone - releases and produces the neurotransmitter so has lots of mitochondria and ER to manufacture and store in vesicles
• Post synaptic neurone - has specific receptor proteins on membrane

Question 16

Why are vesicles containing neurotransmitters signalling molecules?

Answer 16

• Signaling molecules are often called ligands, a general term for molecules that bind specifically to other molecules (such as receptors).
• The message carried by a ligand is often relayed through a chain of chemical messengers inside the cell.