Communication Between Excitable Cells

Question 1

How do neurotransmitters work?

Answer 1

The vesicles of neurotransmitters fuse with presynaptic membrane of the nerve and then pass into the synaptic cleft where the chemicals will diffuse across and make contact with their postsynaptic targets which are the muscle cells

Question 2

What happens in synaptic transmission?

Answer 2

Presynaptic action potential
Depolarisation of synaptic terminal
Opening of voltage gated ca2+ channels
Ca2+ entry and fusion of vesicles with membrane
Transmitter release
Ach receptor activated
Cation channel opens
Activation of ion channels

Question 3

What are end plate potentials?

Answer 3

The voltages which cause depolarisation of skeletal muscle fibres caused by neurotransmitters binding to the postsynaptic membrane in the neuromuscular junction

Question 4

What are the two types of summation?

Answer 4

Spatial summation - occurs when two or more separate inputs arrive almost simultaneously from different presynaptic neurones
Temporal summation - occurs when two or more action potentials arrive in rapid succession

Question 5

What are ESPS and ISPS?

Answer 5

ESPS - excitatory postsynaptic potential - add to generate depolarisation
ISPS - inhibitory postsynaptic potential - add to generate hyperpolarisation