Synapses and neurotransmitters

Question 1

What is a synapse

Answer 1

A gap between 2 neurones

Question 2

There are 2 types of synapses.
Which synapse are we covering

Answer 2

Chemical and electrical
Chemical

Question 3

What are the stages of synapse transmission

Answer 3

Step 1- A nerve impulse arrive

Step 2- Calcium ions rush into the pre-synaptic neurone

Step 3- neurotransmitters diffuse across the synaptic cleft (gap) from a high to low concentration

Step 4- Neurotransmitters bind to the receptors on the post synaptic membrane

Step5 - Opens the sodium channels, so sodium ions diffuse into the post synaptic neurone

Step 6- Creates post-synaptic potential which generates action potential if it reaches the threshold (+40m/v)

Step 7- Neurotransmitters gets recycles back into the presynaptic neurone, they get broken down and put into vesicles

Question 4

Why do synapses only go in one direction

Answer 4

There are only vesicles in the pre synaptic neurone

The concentration gradient only goes from high in the pre synaptic neurone to low in the post synaptic neurone

There are only receptors on the post synaptic neurone

Question 5

What are the 2 types of neurotransmitters and explain what they do

Answer 5

Inhibitory ( decreases the chance of an action potential)
Excitory ( increases the chance of an action potential)

Question 6

Name 3 neurotransmitters

Answer 6

Acetychlonine
Dopamine
Seretonin

Question 7

Acetychlonine

Answer 7

Most common in our body

Can be either excretory or inhibitory depending where it is

When serotonin is recycled it is broken down by the enzyme acetychlonine esterase

Question 8

Dopamine

Answer 8

In the brain

If there’s too little, it causes unusual brain activity called Parkinson diseases and it causes shaking and tremors

It is treated with L- drug which Is a prescusor of dopamine so then there is enough to cause normal levels to bind to the receptors

Question 9

Seretonin

Answer 9

In the brain

If there is too little it causes unusual brain activity called depression

This causes you to have a low mood

Question 10

What are the 2 types of DRUGS that affect synapses

Answer 10

Antagonist
Agonist

Question 11

What does antagonist do and give examples

Answer 11

Blocks receptors so the neurotransmitters can’t bind
e.g atropine and curare

Question 12

What does the agonist do and give example

Answer 12

Helps neurotransmitters to bind to receptors

e.g L dopa: it is a precursor of dopamine so It turns into dopamine and helps stimulate the receptors