Lecture 5 - Synapses

Question 1

what is a synapse?

Answer 1

site at which one neuron communicates with another neuron or effector cell

Question 2

what is the difference between pre and post synaptic neurons?

Answer 2

presynaptic - conducts electrical signal toward a synapse
postsynaptic - transmits electrical signal away from synapse

Question 3

what are the types of synapses?

Answer 3

axodendritic (between axon terminals and dendrites)
axosomatic (between axons and neuronal cell bodies)
chemical synapses (neurotransmitters)
electrical synapses

Question 4

what are chemical synapses composed of?

Answer 4

presynaptic terminal + synaptic cleft + postsynaptic membrane

Question 5

what is the process of neurotransmitters?

Answer 5

action potential in the synaptic vesicles causes neurotransmitter to be released from vesicles -> diffusion of neurotransmitter across synapse -> neurotransmitter binds to receptors on postsynaptic neuron -> ion channels open causing excitatory or inhibitory event

Question 6

what terminates the neurotransmitter effect?

Answer 6

• degradation by enzymes (ACh)
• reuptake of neurotransmitter in presynaptic neuron (serotonin)
• diffusion away from synaptic cleft