Biopsychology: Divisions Of The Nervous System + Neurones

Question 1

The nervous system is made up of :

Answer 1

• The Central Nervous System(CNS) and the Peripheral Nervous system(PNS)

Question 2

What is the central nervous system made up of (CNS)

Answer 2

The brain and the spinal chord.

Question 3

What is the PNS made up of

Answer 3

1) PNS
2) Somatic (voluntary)
2) Autonomic (involuntary)
3) Parasympathetic: digestion during rest
3) Sympathetic: response to stress

Question 4

What are the three types of neurones?

Answer 4

Sensory
Relay
Motor

Question 5

Structure of a sensory neurone related to function

Answer 5

Dendrites: Receive action potential from receptor
Dendron: action potential travels down dendron
Cell body:
Synapse: leaves the sensory neurone to travel to motor neurone
Vesicles: Where a neurotransmitter is held
Mylin sheath: insulator increase speeds of transmission
Nodes of ranvier: action potentials jump

Question 6

Transmission of a neurotransmitter:

Answer 6

• Action potentials reach the presynaptic terminal
• Action potentials trigger release of neurotransmitters
• Neurotransmitters cross the synaptic cleft from vesicles
• Neurotransmitters combine with receptors on the postsynaptic membrane
• Stimulation of postsynaptic receptors by neurotransmitters result in either excitation
(depolarisation) or inhibition (hyperpolarisation) of the postsynaptic membrane.

Question 7

What is (hyperpolarisation):

Answer 7

The inside of the membrane is very negative compared to the outside. This inhibits action potentials as greater stimulus is needed to reach action threshold

Question 8

Summation

Answer 8

The excitatory and inhibitory influences of Neurotransmitters are summed up. If the net effect is inhibitory(hyper polarisation) on the post synaptic neurone then action potentials will be less likely to fire. Similarly is the net effect on the post synaptic neurone is excitatory, the post synaptic neurone will be more likely to fire.

Question 9

What happens after a neurone has been fired:

Answer 9

It is recycled

Re-up take of the neurotransmitter into the pre synaptic terminal