Extension - Synapses

What is a synapse?

• A type of neuron

• A junction or small gap between two neurons or a neuron and effector

• A type of neurotransmitter

• A part of the brain

Which of the following is an importance of synapses in transmitting impulses?

• Ensure impulses are bidirectional

• Allow impulses to be transmitted without delay

• Ensure impulses are unidirectional

• Prevent impulses from being transmitted

What is one function of synapses in the nervous system?

• Ensure impulses are bidirectional

• Ensure impulses are unidirectional

• Allow impulses to stop

• Prevent impulse transmission

What process involves synaptic vesicles fusing with the membrane to release neurotransmitters?

• Endocytosis

• Exocytosis

• Phagocytosis

• Pinocytosis

Which neurotransmitter is an example of an excitatory neurotransmitter?

• Gamma-aminobutyric acid (GABA)

• Dopamine

• Acetylcholine

• Serotonin

What effect do inhibitory neurotransmitters have on the postsynaptic membrane?

• They cause depolarisation of the postsynaptic neurone.

• They result in hyperpolarisation of the postsynaptic membrane.

• They trigger an action potential.

• They have no effect on the postsynaptic membrane.

Which neurotransmitter is an example of an inhibitory neurotransmitter?

• Acetylcholine

• Dopamine

• Gamma-aminobutyric acid (GABA)

• Serotonin

What is the width of the synaptic cleft as shown in the diagram?

• 10 nm

• 20 nm

• 30 nm

• 40 nm

Where are neurotransmitters stored before being released into the synaptic cleft?

• In the postsynaptic neuron

• In the synaptic cleft

• In vesicles in the presynaptic neuron

• In the neurotransmitter receptors

What happens when the action potential reaches the end of the presynaptic neuron?

• Calcium ion channels close

• Calcium ion channels open

• Neurotransmitters are destroyed

• The synaptic cleft widens