The Nervous System - B3.1

Question 1

What is the nervous systems

Answer 1

It detects changes in your external environment, sends it to your brain for the appropriate response

Question 2

Change in the environment

Answer 2

Stimulus

Question 3

Group of cells that detect stimulus

Answer 3

Sensory receptors/sensory cells

Question 4

What occurs the response

Answer 4

Effectors or muscle glands

Question 5

How do receptor cells work/sensory receptors?

Answer 5

Change stimulus into electrical impulses travel along neurons to your central nervous system. 

Question 6

What does CNS stand for and what does it contain

Answer 6

The central nervous system contains the spinal cord and brain

Question 7

Sensory neurons

Answer 7

Carry electrical impulses from receptor cells to the CNS

Question 8

Relay neurons

Answer 8

Carry electrical impulses from sensory neurones to the CNS

Question 9

Motor neurones

Answer 9

Carry electrical impulses from CNS to effectors

Question 10

Nervous system reaction chart:

Answer 10

Stimulus - receptor cells - sensory neurones - spinal chord - brain - spinal chord - motor neurones- effectors - response

Question 11

Reflex action

Answer 11

Automatic or involuntary actions occurring without thinking

Question 12

Reflex arc

Answer 12

Stimulus - receptor cells - sensory neurones - spinal cord - motor neurones- effector - response

Question 13

Dendrite

Answer 13

Where neurone receives most information

Question 14

Nucleus

Answer 14

Where all dna and genetic material is stored

Question 15

Axon

Answer 15

Main body of neurone

Question 16

Fatty tissue in neurone

Answer 16

Myelin sheath

Question 17

Axon terminal

Answer 17

End of axon

Question 18

Cornea

Answer 18

Transparent coating that protects eye and refracts light to come in

Question 19

Pupil

Answer 19

Centre hole in iris - allows light to enter

Question 20

Iris

Answer 20

Coloured ring of muscle tissue - alters pupil size by contracting or relaxing

Question 21

Lens

Answer 21

Bioconvex lens - focuses light clearly on retina

Question 22

Ciliary muscles

Answer 22

Ring of muscle tissue - alters shape of lens

Question 23

Suspensory ligaments

Answer 23

Ligament tissue - connects ciliary muscle to lens

Question 24

Optic nerve

Answer 24

Nervous tissue - carries nerve impulses to brain

Question 25

Images formed

Answer 25

Cornea refracts light rays - light passes though pupil and further refracted by lens - creates sharp image on retina - photoreceptors produce nervous impulse - to optic nerve - to brain as an image

Question 26

To look at nearby objects

Answer 26

Ciliary muscles contract - lens becomes convex (fatter)

Question 27

Focusing on far objects

Answer 27

Ciliary muscles relaxes - lens becomes less convex

Question 28

what causes short- sightedness

Answer 28

Persons lens being too strong or eye ball long

Question 29

what causes long-sightedness

Answer 29

Persons lens too weak - eyeball too short

Question 30

Retina

Answer 30

Area at back of eye which contains clusters of light sensitive cells

Question 31

Sclera

Answer 31

White outer layer of eye. Quite tough so that little damage to eye ball

Question 32

Short sight

Answer 32

Distant objects for light rays meet in front of retina SO - use concave to bend light rays outwards before entering = meet in middle and focus image

Question 33

Long sight

Answer 33

Nearby object light rays go behind retina SO - use convex lenses to bend inwards = meet up in middle

Question 34

Two photoreceptors

Answer 34

Rods - to see dim light, black and white Cones - to see colour

Question 35

Constricting pupil

Answer 35

radial muscles relax and circular muscles of iris contract

Question 36

Dilating pupil

Answer 36

Circular muscles relax and radial muscles contract

Question 37

Frontal lobe

Answer 37

Decision making, reasoning and consciousness of emotions

Question 38

Parietal lobe

Answer 38

Orientation, movement and memory

Question 39

Occipital lobe

Answer 39

Visual cortex - to do with information from eye

Question 40

Cerebellum

Answer 40

Coordinates movement and balance

Question 41

Temporal lobe

Answer 41

Auditory information - hearing and sound and speech

Question 42

Medulla

Answer 42

Controls automatic actions- heart and breathing rate

Question 43

PNS damage

Answer 43

Numbness and loss of coordination but can heal by itself

Question 44

CNS damage

Answer 44

Loss of control to body parts, memory loss and paralysis- cannot regenerate without surgery

Question 45

What is the eyes receptor cells and stimulus

Answer 45

Photoreceptors - light

Question 46

Tongue receptors and stimulus

Answer 46

Taste - chemical

Question 47

Skin receptors and stimulus

Answer 47

Pressure - pressure Temperature- heat

Question 48

Nose receptors and stimulus

Answer 48

Smell - chemical Taste - chemical

Question 49

How do dendrites join other axons

Answer 49

Join by synapses where a neurotransmitter sends information from diffusion

Question 50

What is a synapse

Answer 50

A small gap between two neurones

Question 51

Techniques to investigate brain functions

Answer 51

CT - computerised tomography uses X-rays to create 3D images and show any abnormalities MRI - magnetic resonance imaging uses scanning magnets however new fMRI makes images in real time by measuring blood flow to certain areas which are active

Question 52

Why is brain activity difficult

Answer 52

- nerve fibres are very close together so difficult to track or fix one without affecting others - brain activity could result in permanent damage to brain - unethical as patient may not be making educated choice or decision

Question 53

Dropping ruler experiment

Answer 53

- would measure reaction time - distance travelled - over speed/ velocity of gravity