B5.2 Human nervous system

Question 1

What is the role of the human nervous system?

Answer 1

Enables humans to react to their surroundings and to coordinate their behaviour

Question 2

What is the CNS?

Answer 2

The central nervous system, includes the brain and spinal cord.

Question 3

“To summarise the order of how the human nervous system works, fill in the missing words:
a -> b -> c -> d -> e”

Answer 3

“a) Stimulus

b) Receptor
c) Coordinator
d) Effector
e) Response”

Question 4

Name the three types of neurone.

Answer 4

“1. Sensory

2. Relay
3. Motor”

Question 5

What is a synapse?

Answer 5

The method by which a nervous impulse crosses the gap between neurones.

Question 6

Summarise in five steps how a synapse works.

Answer 6

1. Impulse arrives at the end of neurone A, 2. Neurotransmitter is released into the synaptic gap, 3. Neurotransmitter diffuses across the synaptic gap, 4. Neurotransmitter binds to receptors on neurone B, 5. A new electrical impulse is generated in neurone B.

Question 7

Why are reflex actions rapid?

Answer 7

They do not involve the brain, therefore no conscious thought.

Question 8

What do you use reflex actions for?

Answer 8

Reactions to remove your body from danger.

Question 9

What is the brain made up of?

Answer 9

Billions of interconnected neurones.

Question 10

What is the CNS?

Answer 10

The central nervous system, includes the brain and spinal cord.

Question 11

Name the three main parts of the brain

Answer 11

Cerebral cortex, cerebellum, medulla

Question 12

Why is investigating the function of the brain difficult?

Answer 12

It is a complex and delicate organ.

Question 13

Name two ways scientists can investigate brain function.

Answer 13

1.Electrically stimulating areas in a conscious patients and recording their response OR 2. Magnetic Resonance Imaging (MRI) scans.

Question 14

Name the two stimuli the eye is sensitive to.

Answer 14

Light intensity and colour.

Question 15

Name the muscle that changes the shape of the lens in the eye.

Answer 15

Ciliary muscle

Question 16

Name the ligaments in the eye which help to change the shape of the lens.

Answer 16

Suspensory ligaments

Question 17

Name the part of the eye which controls how much light enters through the pupil.

Answer 17

Iris

Question 18

Name the part of the eye which allows light to enter through it.

Answer 18

Pupil

Question 19

Name the part of the eye which is a transparent covering of the eyeball.

Answer 19

Cornea

Question 20

Name the part of the eye which focuses light into the eye.

Answer 20

Lens

Question 21

Name the part of the eye which gathers information and sends it to the brain.

Answer 21

Optic nerve

Question 22

Name the part of the eye which has no light receptor cells.

Answer 22

Blind spot

Question 23

Name the white part of the eye which acts a protective layer.

Answer 23

Sclera

Question 24

Name the part of the eye which is a thin layer containing millions of receptor cells.

Answer 24

Retina

Question 25

What happens to the suspensory ligaments and ciliary muscles when the eye focuses on NEAR objects?

Answer 25

Suspensory ligaments LOOSEN, ciliary muscles CONTRACT

Question 26

What happens to the suspensory ligaments and ciliary muscles when the eye focuses on FAR objects?

Answer 26

Suspensory ligaments TIGHTEN, ciliary muscles RELAX

Question 27

What shape is the lens in when the eye focuses on NEAR objects?

Answer 27

Thicker, more curved.

Question 28

How does the shape of the lens when it is thicker and more curved affect light refraction?

Answer 28

Refracts light strongly.

Question 29

What shape is the lens in when the eye focuses on FAR objects?

Answer 29

Thinner, less curved.

Question 30

How does the shape of the lens when it is thinner and less curved affect light refraction?

Answer 30

Refracts light slightly.

Question 31

Name the two muscle types in the eye that control the amount of light entering.

Answer 31

Radial and circular.

Question 32

In high light intensities, what happens to these muscles to cause the pupils to constrict?

Answer 32

Radial muscles RELAX, circular muscles CONTRACT.

Question 33

In low light intensities, what happens to these muscles to cause the pupils to dilate?

Answer 33

Radial muscles CONTRACT, circular muscles RELAX.

Question 34

What kind of lens (glasses or contact) would correct myopia?

Answer 34

Concave

Question 35

What kind of lens (glasses or contact) would correct hyperopia?

Answer 35

Convex

Question 36

What monitors and controls body temperature?

Answer 36

The thermoregulatory centre of the brain.

Question 37

What does this monitor the temperature of?

Answer 37

The blood flowing through the brain.

Question 38

Name two ways the body responds if the body temperature is too high.

Answer 38

"1.       Blood vessels dilate (vasodilation) | 2.       Sweat is produced from the sweat glands."

Question 39

How do these responses lower body temperature?

Answer 39

Causes a transfer of energy from the skin to the environment.

Question 40

Name three ways the body responds if the body temperature is too low.

Answer 40

"1.       Blood vessels constrict (vasoconstriction) 2.        Sweating stops 3.        Skeletal muscles contract rapidly (shivering)"