topic 2 - brain and eyes

Question 1

what are some limitations of treating damage and disease in the brain and other parts of the nervous system?

Answer 1

when nerve cells are lost, the condition is permanent and the cells do not regrow ans so they cause further permanent damage

Question 2

how can the difficulties of accessing brain tissue be overcome?

Answer 2

using CT and PET scanners to investigate brain function

Question 3

what is the function of the lens?

Answer 3

focusing lights onto the retina

Question 4

what do sensory neurons do?

Answer 4

carry messages in the form of electrical impulses from receptors in the sense organs to the brain or spinal cord

Question 5

what is the optic nerve?

Answer 5

a bundle of neurons travelling to the brain

Question 6

what is an impulse?

Answer 6

an electrical signal down neurons

Question 7

what is a synapse?

Answer 7

the connection between 2 neurons

Question 8

what is the function of the reflex arc?

Answer 8

protection, its the passage of information in a reflex

Question 9

what does the spinal cord do?

Answer 9

carried information, part of the CNS

Question 10

what is the role of the myelin sheath?

Answer 10

insulates the electrical system, speeds up the process

Question 11

what is the function of the retina?

Answer 11

detects light waves

Question 12

what are some effects of long-sightedness?

Answer 12

eye ball to short
light doesnt bend
light focusing behind the retina

Question 13

what are some effects of short-sightedness?

Answer 13

eye ball too long
retina too curved
light focused in front of the retina

Question 14

what is a neuron?

Answer 14

a nerve cell which carries an electrical impulse

Question 15

what occurs when a synapse happens?

Answer 15

a chemical signal (neurotransmitter) is released

Question 16

what does the medulla oblongata do?

Answer 16

controls heart rate and reflexes

Question 17

what happens when we look at objects that are far away?

Answer 17

our ciliary muscles are relaxed and our lens is thin

Question 18

what is cancer?

Answer 18

the result of changes in calls that lead to uncontrolled cell division

Question 19

what are the 3 types of neurones?

Answer 19

motor
sensory
relay

Question 20

which parts of the eyes are involved in focusing?

Answer 20

the lens and the cornea

Question 21

which type of neuron transmits a signal from the CNS to an effector such as a muscle?

Answer 21

motor neuron

Question 22

which part of the eye controls the amount of light entering the eye?

Answer 22

the iris - it changes the size of the pupil in reflex actions

Question 23

what is a reflex?

Answer 23

not learned
exists for protection
rapid, automatic response to a stimulus

Question 24

what happens when you are looking at objects that arent far away?

Answer 24

our ciliary muscles are contracted and our lens is fat

Question 25

what is cataracts?

Answer 25

clouding of the lens, caused by protein molecules

Question 26

what makes up the CNS?

Answer 26

brain

spinal cord

Question 27

what occurs between 2 neurons?

Answer 27

diffusion

Question 28

what is the function of the iris?

Answer 28

controls pupil size

Question 29

how does the nervous system receive stimuli?

Answer 29

through receptors

Question 30

what is the function of the cornea?

Answer 30

fine tunes the light focusing on the retina

Question 31

how can cataracts be treated?

Answer 31

replacing faulting lens with artificial lens

Question 32

what does the cerebellum do?

Answer 32

divides into 2 halves, used for posture and balance

Question 33

what does the cerebral cortex do?

Answer 33

communicated with each other, in charge of things like senses, language, memory and behaviour