B10 The Nervous System

Question 1

What is homeostatis

Answer 1

Homeostasis is the regulation of the internal conditions of a cell or organism to maintain optimum conditions for function, in response to internal and external changes.

Question 2

Internal body conditions that are contolled

Answer 2

Temperature, blood glucose concentration, water levels

Question 3

What are reflexes

Answer 3

Reflexes are rapid, automatic responses to certain stimuli that are unconscious as they dont involve the brain.

Question 4

What is the reflex arc

Answer 4

Passage of imformation in a reflex

Question 5

What is the reflex pathway

Answer 5

Stimuli receptor sensory neurone, relay neurone, motor neurone, effector, response

Question 6

What is the brain?

Answer 6

The brain is an organ made up of billions of interconnected neurones in the central nervous system and is responsible for complex behaviours.

Question 7

Function of Cerebral Cortex

Answer 7

Consciousness, intelligence, memory and language

Question 8

Cerebellum function

Answer 8

Muscle coordination

Question 9

Medulla

Answer 9

Unconscious activities - breathing and heart beat

Question 10

How to study patients with brain damage? Neuroscientists

Answer 10

MRI scans (magnetic resonance imaging scanner) to see which brain parts are active when a human performs a task. Electrically stimulating the brain. Stimulates part of brain to see what effect it has on the body

Question 11

What is the eye

Answer 11

The eye is a sense organ containing receptors sensitive to light intensity and colour.

Question 12

Iris reflex in dim light

Answer 12

Radial muscle contracted and circular muscle relaxes. Pupils become wider. Pupil dilates

Question 13

Iris reflex in bright light

Answer 13

Radial muscles relax and circular muscles contract. Pupil constricts

Question 14

What is accomodation

Answer 14

This is when your lens chnges shape when you focus on near or distant objects

Question 15

Eye accommodation focusing on a distant object

Answer 15

Ciliary muscles relax and suspensory ligaments pull tight. Lens becomes thin and refracts light rays slightly

Question 16

Eye accommodation focusing on a nearby object.

Answer 16

Ciliary muscles contract and the suspensory ligaments slackens. Lens becomes thicker and refracts light rays strongly

Question 17

What is myopia

Answer 17

Short sightedness. Can’t focus on distant objects as image is focused infront of retina.

Question 18

What is Hyperopia

Answer 18

Long sightedness . Unable to focus on near objects because image is focused behind the retina

Question 19

How to cure myopia

Answer 19

Concave lens which curves inwards so the light rays focus on the retina

Question 20

How to cure hyperopia

Answer 20

Convex lens which curves outwards so the light rays focus on the retina.

Question 21

Ways to improve eyesight

Answer 21

Spectacle lenses. Contact lenses, laser eye surgery, replacement lens

Question 22

Cornea

Answer 22

Refracts light onto lens and is a transparent outer layer

Question 23

Lens

Answer 23

Convex shape that refracts light onto the retina

Question 24

Iris

Answer 24

Controls the size of the pupil. Coloured part and it is a muscle

Question 25

Pupil

Answer 25

A hole in the iris that allows light to enter to enter the eye

Question 26

Retina

Answer 26

Contains light receptors at the back of the eye

Question 27

Optic nerve

Answer 27

Carries impulses between the eye and the brain

Question 28

How is the lens held in place

Answer 28

By the suspensory and ciliary muscles

Question 29

Sclera

Answer 29

Tough white outer layer of the eye that protects it from injury

Question 30

What are the two effectors

Answer 30

Muscles and gland

Question 31

Muscles response to impulses

Answer 31

Contract

Question 32

Glands response to impulses

Answer 32

Secrete chemical substances like hormones or enzymes