Neurones

Question 1

What is the Nervous system made up of? And explain them with points!

Answer 1

> The brain
< The brain is one of the components (parts) of the central nervous system (CNS)
< The CNS coordinates the response of effectors
< Effectors are muscles or glands that act in response to a change in the internal or external environment.

> The spinal cord
< The spinal cord is the other component (part) of the CNS
< It is also important in coordinating the response of effectors to changes in the environment

> The neurones (nerve cells)
< Neurones (nerve cells) carry electrical impulses (signals) between receptors, the central nervous system (CNS) and effectors.

Question 2

At each junction of the reflex arc, there is a synapse… Explain what happens after..

Answer 2

> At each junction of the reflex arc, there is a synapse.

> Synapses are gaps between neurones. Nerve impulses must travel across these gaps:

< The electrical impulse reaches the end of the neurone before the synapse.

< This triggers the release of chemicals called neurotransmitters.

< The neurotransmitters diffuse (move down a concentration gradient) across the synapse.

< The neurotransmitters bind to receptors on the next neurone.

< The presence of the neurotransmitter causes the production of an electrical impulse in the next neurone.

Question 3

What triggers the release of neurotransmitters at a synapse in the brain?

Answer 3

> An electrical impulse

Question 4

Describe the Neurone Structure and what they do.

Answer 4

> Axons carry electrical impulses away from the cell body.

> Dendrites carry electrical impulses towards the cell body.

> Axons are covered in a layer called a myelin sheath. This insulates the neurone, so electrical impulses travel down it more quickly.

Question 5

[ ] bring about actions in response to a change in the internal or external environment. Such actions include muscles contracting and glands secreting hormones. What’s the word missing?

Answer 5

> Effectors

Question 6

Axons are covered in a layer called a [ ] sheath. This [ ] the neurone, so electrical impulses travel down it more quickly. What are the two missing words?

Answer 6

> Myelin

> Insulates