Chapter 10 B Summary Questions

Question 1

What is homeostasis?

Answer 1

regulation of internal conditions of cell or organism
to maintain optimum functional conditions
in response to internal and external changes

Question 2

Explain why the control of conditions inside your body is so important? 3 things

Answer 2

1.to work properly, cells require correct temperature so enzymes work optimally
2. correct concentration of water and mineral ions in blood so osmosis doesn’t cause problems
3. glucose for cellular respiration and removal of waste products as build-up can change pH or poison
systems

Question 3

State the job of your nervous system (2 marks)

Answer 3

enables reaction to surroundings

and coordination of behaviour

Question 4

State where in your body you would find nervous receptors that respond to light

Answer 4

eye

Question 5

State where in your body you would find nervous receptors that respond to sound

Answer 5

ear

Question 6

State where in your body you would find nervous receptors that respond to temperature

Answer 6

skin

Question 7

State where in your body you would find nervous receptors that respond to touch

Answer 7

skin

Question 8

Draw and label a simple diagram of a reflex arc.

Answer 8

diagram to show pathway:

stimulus  receptor  sensory neurone  relay neurone  motor neurone  effector  response sensory

Question 9

Explain how a reflex arc works and why it allows you to respond quicker to danger

Answer 9

receptor detects stimulus and sends electrical impulse along sensory neurone to CNS
impulse then passes along relay neurone and motor neurone, arriving at effector organ bringing about a response
happens very fast
does not involve conscious part of brain

Question 10

State the difference between a neurone and a nerve

Answer 10

neurone is individual nerve cell
nerve is bundle of many neurones
all sensory neurones, all motor neurones, or a mixture

Question 11

Describe how a nerve impulse passes across a synapse. Explain the importance of synapase in the nervous system (4 marks)

Answer 11

1.synapses are junctions forming physical gaps between neurones; electrical impulses travelling along neurones must cross synapse (cannot leap gap)
2. when impulse reaches synapse, chemicals are released into gap between neurones
3 chemicals then picked up by receptor sites on surface of next neurone across synapse, setting up new electrical impulse in next neurone synapses permit transmission of impulses from one neurone to another