Synapses and Role of Neurotransmitters

Question 1

Types of synapse

Answer 1

Electrical

Chemical

Question 2

Describe the steps of neurotransmitters

Answer 2

When the action potential reaches the synapse, the depolarisation triggers the Ca2+ channels to open so Ca2+ floods in. This causes the vesicles containing NT to move to and fuse with the presynaptic membrane. The NT is then released by exocytosis. The NT diffuses across the synapse and binds to the receptor on the postsynaptic membrane, where Na+ channels are opened so the action potential can continue. The signal is terminated by the reuptake or enzymatic breakdown of NT.

Question 3

Receptor signalling mechanisms

Answer 3

ionotropic

metabotropic

Question 4

What is an inotropic receptor?

Answer 4

Receptor operated/ligand gated channels.
Ion movement occurs due to the channel opening.
They can be excitatory using Na+ and an EPSP or inhibitory using Cl- ions and an IPSP.
Fast method of transmission.

Question 5

What is an metabotropic receptor?

Answer 5

Use G protein coupled receptor. Slower and longer lasting method of transmission.

Question 6

What is spatial summation?

Answer 6

The sum of many post synaptic potentials from several separate synapses.

Question 7

What is temporal summation?

Answer 7

Rapid succession of post synaptic potentials from the same synapse.

Question 8

What is Acc broken down by?

Answer 8

Acetylcholine esterase

Question 9

What is myesthenia gravis?

Answer 9

an autoimmune disease of the nicotinic Acc receptors causes a reduction at the neuromuscular junction.
Causes muscle weakness.