The human nervous system

Question 1

Name the three main parts of the brain and state the role of each

Answer 1

cerebral cortex – is the outer ‘wrinkled’ layer of the brain it is responsible for intelligence, language, memory and consciousness
cerebellum – is located at the lower part of the back of the brain and is responsible for voluntary coordination of the muscles
medulla – is located in the lower part of the brain stem it is responsible for involuntary coordination such as breathing, swallowing and heart rate

Question 2

How do neuroscientists study the brain?

Answer 2

Studying patients with brain damage, electrically stimulating the brain and using magnetic resonance imaging (MRI) scanning.

Question 3

What is an EEG?

Answer 3

Electroencephalogram (EEG) is a test used to find problems related to electrical activity of the brain.

Question 4

What is an MRI?

Answer 4

A device that uses strong magnetic fields and radio waves to produce detailed images of the brain and spinal cord.

Question 5

What does an MRI do?

Answer 5

MRI can distinguish between different types of tissues, including detecting cancerous cells.

Question 6

Description and function of cornea.

Answer 6

Transparent layer at the front of the eye, it refracts light into the eye.

Question 7

Description and function of iris.

Answer 7

The coloured part of the eye, contains muscles that control the amount of light entering the eye.

Question 8

Description and function of pupil.

Answer 8

The hole in the middle of the iris that lets light in. Its diameter is controlled by the iris.

Question 9

Description and function of lens.

Answer 9

A transparent, biconvex structure in the eye that refracts light onto the retina.

Question 10

Description and function of retina.

Answer 10

Thin layer of tissue at the back of the eye that contains receptor cells for light and colour.

Question 11

Description and function of sclera.

Answer 11

Tough white supporting wall of the eye.

Question 12

Description and function of ciliary muscles.

Answer 12

Muscles that are connected to the lens by the suspensory ligaments; they change the shape of the lens.

Question 13

Description and function of suspensory ligaments.

Answer 13

These connect the lens to the ciliary muscles.

Question 14

Description and function of optic nerve.

Answer 14

Carries impulses fro the retina to the brain.

Question 15

What is accommodation?

Answer 15

The process of changing the shape of the lens focus on near or distant objects

Question 16

How does the eye focus on distant objects?

Answer 16

The ciliary muscles relax, the suspensory ligaments are pulled tight, the lens is then pulled thin and only slightly refracts light rays

Question 17

How does the eye focus on near objects?

Answer 17

The ciliary muscles contract, the suspensory ligaments loosen, the lens is then thicker and refracts light rays strongly.

Question 18

What is myopia? How can it be corrected?

Answer 18

Short-sightedness, it can be corrected with concave lenses

Question 19

What is hyperopia? How can it be corrected?

Answer 19

Long-sightedness, it can be corrected with convex lenses

Question 20

Name three ways that vision can be corrected?

Answer 20

Contact lenses, laser surgery and lens replacement

Question 21

State the optimum human body temperature.

Answer 21

37*c

Question 22

What part of the brain monitors and controls temperature?

Answer 22

Thermoregulatory centre

Question 23

Describe what happens in vasoconstriction and vasodilation.

Answer 23

• If the body temperature is too low, blood vessels constrict (vasoconstriction), sweating stops and skeletal muscles contract (shiver).
• If the body temperature is too high, blood vessels dilate (vasodilation) and sweat is produced from the sweat glands. Both these mechanisms cause a transfer of energy from the skin to the environment.