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AQA Biology - GCSE > Nervous System > Flashcards

Flashcards in Nervous System Deck (44)
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1
Q

BIOLOGY ONLY - The Eye - What is the function of the retina?

A
  • Retina - conatins light receptors (rod and cone cells)
  • Detects the light and sends electrical impulses to the brain.
2
Q

How do nerve impulses travel across synapses?

A

Chemical messengers

3
Q

What is the difference between and reflex action and a reflex arc?

A

Reflex action follows this general sequence and does not involve the conscious part of the brain, which makes it much quicker. The nerve pathway followed by a reflex action is called a reflex arc.

4
Q

BIOLOGY ONLY - The Eye - What is the function of the sclera?

A

Sclera - tough, opaque outer layer of the eye which protects the eye from injury.

5
Q

BIOLOGY ONLY - The Eye - How can myopia (short sightedness) be corrected?

A

Using concave lens - which bends the light rays outwards so that they are focused on the retina.

6
Q

BIOLOGY ONLY - The Eye - What is myopia?

A

Myopia (SHORTer word) is SHORT sightedness

7
Q

BIOLOGY ONLY - The Eye - Which new technologies can be used to correct eye defects?

A
  • Contact lenses (Hard and soft)
  • Laser surgery to change the shape of the cornea
  • Replacement lens in the eye.
8
Q

BIOLOGY ONLY - The Eye - Describe what happens to eye in bright light

A
  • Circular muscles: Contract to close the pupil
  • Radial muscles: Relax
  • Iris: Gets bigger
  • Pupil: Contracts (gets smaller)
9
Q

BIOLOGY ONLY - Identify the different parts of the brain

A

A) Cerebral cortex B) cerebellum C) medulla (D = Hypothalamus)

10
Q

How does the structure of a motor neurone relate to its function?

A
  • Structure: Have a myelin sheath for faster transmission; packed with mitochondria
  • Function: Carry electrical impulses away from the CNS to effectors
11
Q

What is a myelin Sheath

A

This insulates or protects neurones

12
Q

BIOLOGY ONLY - What is the function of the brain?

A

The brain controls complex behaviour. It is made of billions of interconnected neurones and has different regions that carry out different functions.

13
Q

What is a receptor? Give examples

A
  • A receptor is a sensory cell which detects changes in the environment (stimuli) and passes this information to attached sensory neurones.
  • Examples include rod and cone cells in the retina of the eye and temperature / pressure or pain receptors in the skin.
14
Q

What is the CNS?

A
  • The Central nervous system (CNS).
  • The CNS is the brain and spinal cord
15
Q

How do nerve impulses travel across synapses?

A

Chemical messengers (called neurotransmitters) diffuse across the synapse (the gap) and bind with receptor molecules on the membrane of the second neurone.

16
Q

BIOLOGY ONLY - The Eye - What is the function of the iris?

A

Iris - controls the amount of light that enters the eye.

17
Q

List the sequence of events in a reflex

A

stimulus > receptor > coordinator > effector > response

18
Q

BIOLOGY ONLY - The Eye - What is hyperopia?

A

Hyperopia (LONGer word) is LONG sightedness

19
Q

BIOLOGY ONLY - The Eye - What is the function of the ciliary muscles?

A

Ciliary muscles - attaches the ciliary muscle to the eye and helps to change the shape of the lens.

20
Q

BIOLOGY ONLY - The Brain - What is the function of the cerebellum?

A

cerebellum - controls balance, co-ordination of movement and muscular activity.

21
Q

BIOLOGY ONLY - The Eye - Identify structures in the eye

A
22
Q
  • What is an effector? Give examples
A
  • An effector is linked to a motor neurone and causes a response.
  • Examples: muscles contracting or glands secreting hormones.
23
Q

BIOLOGY ONLY - The Eye - Describe what happens to eye in dim light

A
  • Circular muscles: Relax
  • Radial muscles: Contract to open the pupil
  • Iris: Gets smaller
  • Pupil: Relaxes (opens)
24
Q

Exam Question: Features of neurones

A
25
Q

Give 3 features of reflex actions

A
  • Automatic
  • Rapid
  • Do not involve the conscious part of the brain.
26
Q
  • How does the structure of a relay neurone relate to its function?
A
  • Structure: no myelin sheath so slower transmission
  • Only found in the spinal cord and brain.
  • Function: Carry electrical impulses from sensory to motor neurones
27
Q

BIOLOGY ONLY - The Brain - What is the function of the medulla?

A

medulla - controls unconscious activities such as heart rate and breathing rate

28
Q

BIOLOGY ONLY - The Eye - What is accommodation?

A

The process of changing the shape of the lens to focus on near or distant objects.

29
Q

BIOLOGY ONLY - The Eye - What is the function of the suspensory ligaments?

A

Suspensory ligaments - attaches the ciliary muscle to the eye and helps to change the shape of the lens.

30
Q

BIOLOGY HIGHER ONLY - The Brain - What are the difficulties of investigating brain function and treating brain damage and disease?

A

The complexity and delicacy of the brain makes investigating and treating brain disorders very difficult.

31
Q

What is the function of the nervous system?

A

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

32
Q

BIOLOGY ONLY - The Eye - What is the function of the cornea?

A

Cornea - transparent front part of the eye which focuses the light by a fixed amount

33
Q

BIOLOGY ONLY - The Eye - How does the eye focus on a near object?

A

• the ciliary muscles contract • the suspensory ligaments loosen • the lens is then thicker (fatter) and refracts (bends) light rays strongly.

34
Q

BIOLOGY ONLY - Exam Question: Brain Function

A
35
Q

How does the structure of a sensory neurone relate to its function?

A
  • Structure: Have a myelin sheath for faster transmission; packed with mitochondria
  • Function: Carry electrical impulses to the CNS from receptors
36
Q

BIOLOGY ONLY - The Eye - What is the function of the optic nerve?

A

Optic nerve - carries electrical impulse from the retina to the brain.

37
Q

What is the function of the CNS?

A

To coordinate the response of effectors which may be muscles contracting or glands secreting hormones.

38
Q

What is a synapse?

A

A gap / junction / connection between neurones.

39
Q

Why does the pupil get smaller in bright light?

A

To prevent damage to the retina

40
Q

BIOLOGY ONLY - The Brain - What is the function of the cerebral cortex?

A

cerebral cortex - controls intelligence, personality, conscious thought and high-level functions, such as language and verbal memory.

41
Q

What is a stimulus?

A

A change in the environment.

42
Q

BIOLOGY ONLY - The Eye - How can hyperopia (long sightedness) be corrected?

A

Using convex lens - which bends the light rays inwards so that they are focused on the retina.

43
Q

BIOLOGY HIGHER ONLY - The Brain - How have neuroscientists been able to map the regions of the brain to particular functions?

A

By studying patients with brain damage, electrically stimulating different parts of the brain and using MRI scanning techniques.

44
Q

BIOLOGY ONLY - The Eye - What is the eye’s function?

A

A sense organ containing receptors sensitive to light intensity and colour.