Show:
Nerves 1
Nerves 2
Nerves 3
Eye 1
Eye 2
100
What is the name we give to a nerve cell
Neurone
100
What makes up the central nervous system?
Spinal chord and brain.
100
What is the name of the long thin part of a neurone called?
The Axon
100
Name four parts of the eye?
Any four from: cornea lens iris pupil ciliary muscle vitreous humour aqueous humour retina optic nerve
100
What is the name of the hole in the middle of the eye? What does it do?
The pupil. Controls how much light enters the eye.
200
Name the three types of neurones
Sensory neurone Relay neurone Motor neurone
200
Why is a reflex arc so fast?
Because it only goes to the spinal chord and back and doesn't involve the brain, (and therefore conscious thought).
200
name the three parts to a nervous response.
Stimulus Receptor Effector
200
What is special about the lens of an eye? What can therefore do?
It can change shape / get thinner or fatter It can therefore focus light (onto the retina).
200
What is the white, tough outside of the eye called?
The sclera
300
What is the name of the fatty sheaths (cells covering) a neurone?
Myelin sheath
300
What is the part of the nervous system that is not the central nervous system - the sensory and motor neurones outside the central nervous system.
The peripheral nervous system
300
what is the language of the nerves? What type of impulse travels down nerves?
Electrical impulse
300
Name one of the fluid /jelly like substances in the eye?
Either: the aqueous Humour or the vitreous humour
300
What is the light sensitive part of the eye onto which light is focused?
The retina
400
What are the names of the spaces / crevices between the fat sheath cells surrounding the nerve cells? (The places where there are gaps between the fat cells?)
The nodes of ranvier
400
What is the junction between two nerve cells called?
A synapse.
400
Give three examples of a reflex action.
Any three from: Knee jerk coughing / choking heat / hand removal pupil dilation or other valid.
400
What is strange about the image that we perceive on the retina?
It is upside down.
400
What muscles control the shape of the lens in the eye?
The ciliary muscles
500
What kind of chemicals are found in the junctions between nerves?
Neurotransmitters (they cross the synapse and pass the nerve signal on like dominoes).
500
What is the advantage of a reflex action?
It allows an organism to respond quicker to a stimulus.
500
What are the finger like projections that receive messages from lots of other nerves that look like a web of nerves at the end of a neurone?
Dendrites
500
What is the shape of the lens when it is relaxed? Will this help to see objects that are close or far away?
The lens will be thin / flat This will help to see objects far away.
500
What is the smallest fraction of light that stimulate the photo rectors at the back of the eye?
Photons. (Photons are what light is made of - tiny packets of energy that travel in waves - these stimulate photoreceptors and excite them, creating an electrical signal that travels up the optic nerve where it is translated into an image by the brain).