B3.1 - The Nervous System

Question 1

What is a stimulus?

Answer 1

A change in the environment detected by the body

Question 2

What is a receptor?

Answer 2

A group of cells/organ that detects a stimulus

Question 3

What is a sensory neurone?

Answer 3

A nerve cell that carries an impulse to your brain to understand the stimuli detected by the effectors

Question 4

What is a motor neurone?

Answer 4

A nerve cell that sends impulses from the central nervous system to effectors to cause a response

Question 5

What is the Central Nervous System?

Answer 5

The cooperation between the brain and spinal cord to help us detect and react to external stimuli

Question 6

What is the Periphery Nervous System?

Answer 6

The network of nerves that runs throughout your body carrying impulses

Question 7

What is the pathway of the impulse from receptor to effector?

Answer 7

Stimulus
Receptor
Sensory neurone
Central nervous system
Motor neurone
Effector
Response

Question 8

What is the overall function of the nervous system?

Answer 8

To send messages from the body to the brain, and from the brain to the body to give a response to that stimulus, regulating thoughts and movements

Question 9

What are some examples of stimuli?

Answer 9

Change in temperature
Taste
Pain

Question 10

What is the function of the relay neurone?

Answer 10

Carries electrical impulses from sensory neurones to motor neurones

Question 11

What is the cornea and its function?

Answer 11

Transparent coating on the front of the eye
Protects the eye
Refracts light entering the eye

Question 12

What is the iris and its function?

Answer 12

Coloured ring of muscle tissue surrounding the iris
Alters pupil size by contracting or relaxing

Question 13

What is the pupil and its function?

Answer 13

Central hole in the iris
Allows light to enter the eye

Question 14

What is the lens and its function?

Answer 14

Transparent bioconvex lens
Focuses light clearly onto the retina

Question 15

What are the ciliary muscles?

Answer 15

Rings of muscle tissue
Alters the shape of the lens

Question 16

What are the suspensory ligaments and their function?

Answer 16

Ligament tissues that connect ciliary muscles to the lens

Question 17

What is the retina and its function?

Answer 17

Nervous tissue that carries nerve impulses to the brain

Question 18

What happens when the eye focuses on near objects?

Answer 18

Ciliary muscles contract
Suspensory ligaments relax and loosen
The lens thickens and increases curvature to allow light to refract stronger

Question 19

What happens when the eye focuses on distant objects?

Answer 19

Ciliary muscles relax
Suspensory ligaments contract and tighten
The lens becomes thinner and flatter to allow light to refract more weakly

Question 20

In normal vision, where is the image formed?

Answer 20

The fovea

Question 21

In normal vision, why is the image formed at the fovea?

Answer 21

Light refracts through the lens due to its curved biconvex structure

Question 22

What is myopia?

Answer 22

Also known as near-sightedness, where light from distant objects focuses in front of the retina
Distant objects appear blurry while close objects appear normal

Question 23

In myopia, where is the image formed?

Answer 23

Before light reaches the fovea

Question 24

What causes myopia?

Answer 24

The shape of the lens is too strong and too curved, so there is too much refraction

Question 25

What can be done to correct myopia?

Answer 25

It can be managed with a concave lens to reduce refraction of light

Question 26

What is hyperopia?

Answer 26

Also known as long-sightedness, where light from close objects focuses behind the retina
Close objects appear blurry while distant objects appear normal

Question 27

In hyperopia, where is the image formed?

Answer 27

After light reaches the fovea

Question 28

In hyperopia, where is the image formed?