The Nervous System

Question 1

Name the type of particle whose movement in and out of neurons is an essential feature of nerve impulse transmission.

Answer 1

Ion

Question 2

One of the roles of ions is the activation of neurotransmitters. Give an account of how neurotransmitters work.

Answer 2

1) an electrical nerve impulse arrive at the end of the first neuron
2) This results in the formation of vesicles containing a chemical called a neurotransmitter
3) these neurotransmitter vesicles burst at the end of the neuron and the neurotransmitter is released across the synaptic cleft
4) the neurotransmitter stimulates a new nerve impulse in the second neuron.
5) an enzyme breaks down the neurotransmitter within the synaptic cleft during the refractory period

Question 3

Distinguish between the position of the cerebellum and the position of the cerebrum in the human brain.

Answer 3

Cerebellum is located in the hind brain.

Cerebrum is the largest part of the brain.

Question 4

State three functions of the cerebrum.

Answer 4

1) vision
2) smell
3) hearing/ language

Question 5

What is meant by the term “degnerative illness”?

Answer 5

Illness that gets worse

Question 6

Is Alzheimer’s disease driven by a single gene or by many genes?

Answer 6

Many genes

Question 7

What is thought to cause the disease Alzheimer?

Answer 7

A build up of protein-based plaques in the brain.

Question 8

Suggest a possible symptom of Alzheimer disease?

Answer 8

Memory loss

Question 9

How is the advance of technology helping in the fight against Alzheimer?

Answer 9

Can scan brain which helps to examine signs of trouble and defect.

Question 10

There a probably more people suffering from Alzheimer than ever before. suggest a reason for that.

Answer 10

Larger population, which live longer.

Question 11

Name another disorder of the nervous system than Alzheimer and give one possible treatment.

Answer 11

Parkinson/ Physiotherapy

Question 12

Distinguish between the central nervous system and the peripheral nervous system.

Answer 12

CNS- brain and spinal cord

PNS - consists of nerves running out from the CNS

Question 13

Give one way in which nervous response differs from a hormonal response.

Answer 13

Message is electrical- Hormone chemical

Question 14

Give one function EACH of any two parts found ONLY in neurons.

Answer 14

1) Axon carries the impulse away from the cell body

2) schwann cells protect and insulate the axon

Question 15

Name and state the role of any two types of neuron,other than the motor neuron.

Answer 15

SENSORY NEURON -carry impulses from receptors to the central nervous system
INTERNEURONS connect motor&sensory neurons

Question 16

State one function of Hypothalamus.

Answer 16

Homeostatis

Question 17

State one function of Cerebellum.

Answer 17

Balance/ responses are involuntary

Question 18

State function of medulla oblangata.

Answer 18

Breathing

Question 19

In relation to the nervous system, distinguish between grey matter and white matter.

Answer 19

WHITE MATTER contains axons

GREY MATTER contains cell bodies and dendrites;many axons

Question 20

Name a possible cause for Parkinson other than accident.

Answer 20

Brain does not produce enough of the neurotransmitter dopamin

Question 21

What is a reflex action?

Answer 21

An automatic response to a stimulus which is nit under conscious control

Question 22

Give an example of a reflex action.

Answer 22

Sneezing

Question 23

Suggest an advantage of refelx actions.

Answer 23

Protects the body

Question 24

Write notes about Neurotransmitters.

Answer 24

Are chemicals which have been released from neurotransmitter swellings.
The end of a neuron consists of many synaptic knobs which contain numerous small vesicles filled with chemicals called neurotransmitters,e.g. Acetylcholine.

Question 25

What is a neuron?

Answer 25

A neuron is a nerve cell.

Question 26

Distinguish between SENSORY,MOTOR and INTERNEURONS

Answer 26

SENSORY: take messages from sense organs to the CNS
MOTOR: take messages from the CNS to muscles and glands, causing them to respond
INTERNEURONS: carry information between sensory and motorneurons.
only found in the CNS.

Question 27

Briefly explain the role of neurotransmitter substances.

Answer 27

Neurotransmitter chemicals carry the impulse from one nerve cell to another.

Question 28

State a function for Schwann cells.

Answer 28

Secrete a fatty insulating layer called the myelin sheet.

Question 29

State a function of the Myelin sheat.

Answer 29

Insulates the electrical impulses.

Question 30

What is a synapse?

Answer 30

A synapse is a region between 2 neurons or between a neuron and an effector

Question 31

What do you understand under the term THRESHOLD ?

Answer 31

Minimum stimulus needed to cause an impulse to be carried.

Question 32

What is the “all or nothing law” ?

Answer 32

States that if the threshold is reached an impulse is carried, but if the treshold is not reached no impulse is carried.

Question 33

What do you understand under the term “refractory period” ?

Answer 33

Short timespan after a neuron has carried an impulse during which a stimulus fails to cause a response.