B3.1 The Nervous System

Question 1

What is the difference between the central nervous system and the peripheral nervous system?

Answer 1

The central nervous system is the brain and the spinal cord, the peripheral nervous system is every other part of the nervous system

Question 2

What is a stimulus?

Answer 2

A stimulus is a change in the environment

Question 3

What type of neurone connects a receptor to the CNS?

Answer 3

A sensory neurone

Question 4

What is an effector?

Answer 4

A part of a body that brings about the response to a stimulus like a muscle or a gland

Question 5

What type of neurone connects the CNS to an effector?

Answer 5

A motor neurone

Question 6

Describe the reflex arc

Answer 6

Stimulus detected by a receptor
Impulse passed along sensory neurone to CNS Impulse passed along motor neurone to effector
Effector brings about the response

Question 7

What is the cornea and what is its function?

Answer 7

The transparent layer in front of the eye that protects the eye from damage

Question 8

What is the iris and what is its function?

Answer 8

The coloured ring around the pupil that controls its diameter

Question 9

What is the pupil and what is its function?

Answer 9

The pupil is the hole in the middle of the iris that lets light into the eye

Question 10

What is the optic nerve and what is its function?

Answer 10

The nerve coming out the back of the eye that sends signals to the brain

Question 11

What is the function of the lens?

Answer 11

The lens focuses the light rays onto the retina

Question 12

What is the retina and what is its function?

Answer 12

The retina is the back part of the eye and it converts visual stimuli into electrical impulses

Question 13

What do the ciliary body and suspensory ligaments do?

Answer 13

They control the shape of the lens (accomodation)

Question 14

What defect in the eye causes short sightedness?

Answer 14

The lens focuses light rays in front of the retina so far away objects appear blurry

Question 15

How is short sightedness corrected?

Answer 15

By wearing glasses that have concave lenses

Question 16

What defect in the eye causes long sightedness?

Answer 16

The lens focuses light behind the retina so nearby objects appear blurry

Question 17

How is long sightedness corrected?

Answer 17

By wearing glasses that have convex lenses

Question 18

What is colour blindness?

Answer 18

• It is an inherited condition where people find it difficult to tell the difference between colours
• It is caused by a defect in the retina and there is currently no cure

Question 19

Where is the cerebrum located and what is its function?

Answer 19

• It is located at the front of the brain

- It controls conscious functions, memory and language

Question 20

Where is the cerebellum located and what is its function?

Answer 20

• It is located at the back bottom of the brain

- It controls muscular movement and balance

Question 21

Where is the medulla located and what is its function?

Answer 21

• It is located in the brainstem in the middle at the bottom

- It controls unconscious functions like heart rate and breathing

Question 22

What is the function of the hypothalamus?

Answer 22

• It acts as the regulatory centre and controls things like body temperature, water content and salt balance

Question 23

What is the function of the pituitary gland?

Answer 23

• It releases hormones into the blood

Question 24

Give 2 reasons why it is difficult to investigate brain function (Higher)

Answer 24

• Surgery is not risk free

- People with brain disorders may be unable to consent

Question 25

Why is it difficult to treat brain disorders? (Higher)

Answer 25

• The brain and spinal cord are very difficult to access
• Tissues in the CNS cannot regenerate
• Drugs cannot penetrate the blood-brain barrier