neurons and synaptic transmission

Question 1

structure of neurons

Answer 1

dendrites at one end of neuron receive signals from other neurons or sensory receptors and are connected to cell body - control centre of neuron
from cell body, impulse is carried along axon where it terminates at axon terminal.
myelin sheath - allows nerve impulses to transmit more rapidly along axon.

Question 2

different neurons

Answer 2

sensory neuron - carries messages from PNS to CNS. long dendrites, short axons

relay neuron - connects sensory neurons to motor or other relay neurons. short dendrites, short axons

motor neurons - connect CNS to effectors such as muscles and glands. short dendrites, long axons

Question 3

synaptic transmission

Answer 3

electrical impulses reach presynaptic terminal

electrical impulses trigger release of neurotransmitters from vesicles

neurotransmitters diffuse across synapse and bind to receptors on postsynaptic membrane

stimulation of postsynaptic receptors by neurotransmitters leads to either excitation or inhibition of postsynaptic membrane