Describe the nervous system

Describe the hormonal system

What is a chemical mediator?

Give two examples of chemical mediators:

Histamine
a) Where is it stored?
b) When is it released?
c) What is its effect?

Prostaglandins
a) Where are they found
b) When are the released?
c) What effect do they have?

What are plant growth factors and what do they respond to?

How does the plant growth hormone IAA cause a shoot to bend towards the light?

What are neurones?

Describe the following structures, that make up a mammalian neurone:
a) Cell body
b) Dendrons

Describe the following structures, that make up a mammalian neurone:
a) Axon
b) Schwann cells

Describe the following structures, that make up a mammalian neurone:
a) Myelin sheath
b) Nodes of Ranvier

Describe the structure of a sensory neurone

What is the function of a sensory neurone?

Describe the structure of a motor neurone

What is the function of a motor neurone?

Describe the function of an intermediate neurone

What is a nerve impulse?

Describe how sodium and potassium can be transported across the phospholipid cell membrane

What is a resting potential?

How is the resting potential maintained?

What is an action potential?

How does a stimulus cause an action potential?

Generally describe the movement of an action potential down an unmyelinated axon

How does a localised electric circuit propogate the depolarisation (caused by an action potential) down an unmyelinated neurone?

How does an action potential travel down a myelinated neurone?

What three factors affect the speed of the action potential?

How does the myelin sheath increase the speed of a nerve impulse?

How does the diameter of the axon increase the speed of the nerve impulse?

How does temperature affect the speed of a nerve impulse?

What is the refractory period?

What three purposes does the refractory period serve?

What is the all-or-nothing principle?

Describe the function of a synapse

What is meant by the term 'unidirectionality'?

Why is summation often necessary in order to produce an impulse in the postsynaptic neurone?

What are the two types of summation?

What is spatial summation?

What is temporal summation?

What is a cholinergic synapse?

What does the opening of calcium ion channels cause?

How does the acetylcholine trigger an action potential in the postsynaptic neurone?

How is acetylcholine 'recycled' and what is the importance of this?