Exam PPQ's

Question 1

Outline the process of synaptic transmission: (4)

Answer 1

• The neuron is activated by a stimulus.
• An action potential occurs creating an electrical impulse.
• The impulse travels down the axon to the synaptic terminal.
• Triggering vesicles filled with neurotransmitters to be released into the synaptic cleft.
• Neurotransmitters reach the receptors on the post-synaptic neuron.
• Signalling for an electrical impulse to be released.

Question 2

Identify two glands that form part of the endocrinal system and outline their functions. (4)

Answer 2

Possible content:
• Pituitary gland releases ACTH, vasopressin, luteinizing hormone. Controls release of hormones from other glands.
• Adrenal gland and adrenaline/noradrenaline, causing physiological changes associated with arousal, fight and flight.
• Credit also other glands - pancreas and insulin, ovaries and oestrogen/progesterone, testes and testosterone.

Question 3

Briefly outline how excitation and inhibition are involved in synaptic transmission. (4)

Answer 3

• Neurotransmitters can be excitatory or inhibitory (most can be both but GABA is purely inhibitory).
• If the neurotransmitter is excitatory then the post synaptic neuron is more likely to fire an impulse.
• If the neurotransmitter is inhibitory then the post synaptic neuron is less likely to fire an impulse.
• The excitatory and inhibitory influences are summed, if the net effect on the post synaptic neuron is inhibitory, the neuron will be less likely to ‘fire’ and if the net effect is excitatory, the neuron will be more likely to fire.