Chapter 10 - The Human Nervous System

Question 1

Describe homeostasis.

Answer 1

• Regulation of internal conditions of an organism to maintain optimum conditions for function, in response to internal and external conditions.

Question 2

Give 3 examples of a control system.

Answer 2

• Receptors
• Effectors
• Coordination centres

Question 3

Describe the functions of the receptor.

Answer 3

• Detecting change (stimuli) in the external or internal environment.

Question 4

Describe the function of the effector.

Answer 4

• Muscles initiating a response to the stimulus.

Question 5

What does the coordination centre do?

Answer 5

• Receives and processes information from receptors.

Question 6

Give 3 examples of internal conditions controlled by homeostasis.

Answer 6

• Body temperature
• Water levels
• Blood glucose concentration

Question 7

How does the nervous system protect you from danger?

Answer 7

• It uses electrical impulses to enable you to react to you surroundings.

Question 8

RQP - Describe an experiment to measure the reaction time of a person. [6]

Answer 8

• Ruler drop test [1]
• Assistant holds the ruler above your hand [1]
• Top of the thumb in line with 0cm [1]
• Assistant drops the ruler [1]
• Catch as soon as possible [1]
• Record the distance the ruler dropped, from 0cm to top of your thumb. [1]

Question 9

Describe the pathway the nervous system takes to enable a reaction.

Answer 9

Stimulus - Receptor - Coordinator - Effector

Question 10

Describe what a reflex is.

Answer 10

• Automatic and rapid responses to prevent harm.

Question 11

State the 3 neurones involved in enabling reflexes.

Answer 11

• Sensory neurone
• Motor neurone
• Relay neurone

Question 12

State the reflex pathway

Answer 12

Stimulus - Receptor - Sensory Neurone - Relay Neurone - Motor Neurone - Effector - Response

Question 13

What is synapse?

Answer 13

• A gap between neurones which carry the electrical impulses.

Question 14

State the function of the cerebral cortex.

Answer 14

Contains conscious thought, including emotion, decision making and memory.

Question 15

What does the medulla do inside the brain?

Answer 15

Controls heart rate and breathing and subconscious thought.

Question 16

Give the function of the cerebellum.

Answer 16

Enables balance and muscle coordination.

Question 17

What is the function of the pituitary gland?

Answer 17

Release of hormones and control of the menstrual cycle.

Question 18

Give 2 ways which scientists can use to study damaged areas of a patients brain.

Answer 18

Electrical brain stimulation.

MRI scans.

Question 19

Describe the pathway of light through the eye. [5]

Answer 19

Light enters via pupil/cornea through aqueous humour. [1]
Lens focuses light. [1]
Retina detects focused light. [1]
Message passed through blind spot to optic nerve. [1]
Optic nerve delivers message to brain. [1]

Question 20

What is the function of the iris?

Answer 20

Controls size of eye and amount of light entering the eye.

Question 21

State the functions of the ciliary muscles and suspensory ligaments.

Answer 21

Changes shape of lens to fine focus light on retina.

Question 22

Describe what someone will be affected by when they are diagnosed with myopia.

Explain a method of treatment.

Answer 22

Distant objects are blurred, but close objects are in clear focus.

Use glasses with concave lens to spread light out from distant objects before the eye is reached.

Question 23

Describe hyperopia.

Give a possible treatment.

Answer 23

Clear focus on distant objects, but close objects appear blurred.

Use of glasses with a convex lens to bring the light together before the eye is reached.

Question 24

Evaluate the use of contact lenses to help a patient with an eye defect. [6]

Answer 24

Points for:
You can play sports much easier. [1]
Lenses are comfortable [1]
Made of flexible material [1]

Points against:
Short lifetime [1]
Need removal every night [1]
Need storage in sterile solution [1]

Question 25

Describe the process of applying a replacement lens.

Give 1 positive and negative of using replacement lens.

Answer 25

Adding another lens in the eye to correct the visual defect.

P - Corrects the visual defect permanently.
N - Possible damage to retina and/or infections.