Download Week 2 Homework Nervous system

Week 2 Homework Nervous system
1. Copy and complete:
(a) The central nervous system consists of the brain and the spinal cord
(b) The Peripheral nervous system consists of all the nerves that connect to the central
nervous system.
(c) Sensory and effector nerve cells have a long tail like structure called an axon.
(d) The gap between two nerve cells is called a Synapse.
(e) A reaction that does not involve conscious control is called a reflex action.
3. Explain why animals need a nervous system.
Animals have to be able to obtain food, remove wastes, detect what is going on in
their surroundings and respond in ways that ensure their survival.
4. Describe the role of neurotransmitter molecules at a synapse.
The neurotransmitter alters the chemical surroundings of the next neuron’s dendrites
5. Distinguish between:
(a) a receptor and an effector
(b) a sensory neuron, an interneuron and a motor neuron
(c) a neuron and a nerve
(d) a reflex action and a conscious respons
6. Construct a diagram to describe how impulses are transmitted between sensory and
motor neurons.
7. Explain why the axon of neurons is covered with a myelin sheath.
It is essential for the proper functioning of the nervous system. It is an outgrowth of a
type of glial cell.
8) Which of the following are reflex actions?
Blinking.
9) What reflex action occurs when:
(a) Dust gets caught in your nose?
You sneeze.
(b) You step on a prickle?
Pull your foot away very quickly.
10) Politicians are sometimes accused of having ‘knee-jerk reactions’.
(a) Define the term ‘knee-jerk reaction’
When you hit your knee and your reaction is the kick out.
(b) How do you think the term got its name?
From what it describes it does.
11) Why does the pupil of your eye grow bigger in dim light?
So more light can get into the eye.
12) Investigate the effects of an illness on the nervous system. Choose one of the
following: multiple sclerosis:
Sensation changes
Muscle weakness
Muscle spasms
Movement difficulties
Reduced coordination and balance
Speech or swallowing problems
Visual disturbances
Fatigue
Acute or chronic pain syndromes
Bladder and bowel difficulties
Cognitive impairment
Depression
13) Test your ability to identify the sequence of events required to kick a ball by
completing the A nervous response interactivity.
14) Use the Nervous system web link in your eBook PLUS and play the nervous
system game. After playing this game, explain why a person who injures her lower
spine may lose control of her legs but still have control of her arms, whereas injury to
the spine in the neck region may result in the loss of control of muscles in numerous
parts of the body.