the brain

Question 1

the brain blood supply Requires what % body’s oxygen supply

Answer 1

20%

4 min lack of oxygen => permanent damage

Question 2

the brain blood supply requires a continuous supply of what

Answer 2

glucose

Question 3

the brain is protected by what

Answer 3

blood-brain barrier

Allows lipid soluble materials: O2, CO2, alcohol, anaesthetic agents but controls entry of other materials

Question 4

what is the brain created by

Answer 4

tight capillaries and glial cells

astrocytes

Question 5

name the majour areas of the brain

Answer 5

brain stem - (continuous with spinal cord)

diencephalon - (above brain stem)

cerebrum - (at top and largest part)

cerebrum - (back of brain stem)

Question 6

name the main parts to the brain stem

Answer 6

medulla
oblongata
pons
midbrain

Question 7

explain the medulla (part of the brain stem)

Answer 7

medulla is inferior/ lower part of brain stem

Made up of white matter extending between spinal cord & other parts of brain

Contains several nuclei/clusters of cell bodies:
- 3 Vital Reflex Centres
1. Cardiovascular centre (heart rate)
2. Medullary rhythmicity area- (respiratory rhythm)
3. Vasomotor –(vasoconstriction)
4. Other sensory & reflex motor areas: e.g. sneezing, coughing and vomiting.

Question 8

explain the pons (part of the brain stem)

Answer 8

Located above/superior to medulla oblongata

Connects the spinal cord with the brain
- links one part of the brain with another by way of tracts/groups of nerve axons.

Nerves tract cross here
- nerves supplying left side of body cross to right side of brain and from right side of body to left side of brain.

Question 9

explain the midbrain (part of the brain stem)

Answer 9

Connects pons to Diencephalon

Conveys motor impulses from cerebrum to cerebellum and spinal cord

Contains the substantia nigra
- areas affected by Parkinson’s disease - dopamine

Conveys sensory impulses from spinal cord to thalamus.

Question 10

name the parts of the diencephalon in the brain

Answer 10

Thalamus, hypothalamus & pineal gland

melatonin
- High levels of melatonin in winter
- Seasonal affective disorder

Question 11

explain the thalamus (part of the diencephalon)

Answer 11

critical relay for sensory input

Transmits motor information from cerebellum & basal nuclei to cerebrum

Question 12

explain the hypothalamus (part of the diencephalon)

Answer 12

important for homeostasis

1. Control of ANS-regulation of many activities
2. Control of pituitary and hormone production
3. Regulation of emotional & behaviour patterns
4. Regulation of eating & drinking

5.Control of body temperature

6. Regulation of circadian rhythms & states of consciousness

Question 13

explain the pineal gland (part of the diencephalon)

Answer 13

secretes melatonin which promotes sleep

Question 14

describe the parts of the cerebrum

Answer 14

Surface covered with grey matter- cortex

Beneath is cerebral white matter

Question 15

name and describe the parts of the cerebrum structure

Answer 15

Cerebral cortex
- grey matter/cell bodies

Internal white matter

Surface folds
- gyri – gyrus (singular)

Grooves between
- sulci - sulcus

Longitudinal Fissure
- divides it into left & right hemispheres

Connected by corpus callosum

Question 16

each cerebral hemisphere has how many lobes (and name them)

Answer 16

4
Frontal,
parietal,
temporal,
occipital

Question 17

name and describe the functional areas of the cortex

Answer 17

Specialised areas anatomically located

Sensory areas:
- receive input and responsible for perception

Motor areas:
- initiate movements

Associative areas:
- complex integration: e.g. memory, emotion, reasoning, etc.

Question 18

explain brain lateralisation

Answer 18

Left side receives input from & sends output to right side of body and vice versa

Left side of cerebrum important for spoken & written language, numerical & scientific skills & reasoning

Right side of cerebrum more involved with spatial and pattern recognition and emotional content

Question 19

what does cerebellum mean

Answer 19

‘little brain’

Question 20

name the parts of the cerebellum

Answer 20

Cranial meninges (continuous with spinal meninges)
dura mater,
arachnoid mater
& pia mater

Question 21

describe the structure of the cerebellum

Answer 21

Two cerebellar hemispheres
- posterior to medulla and pons, below cerebrum

Cerebellar cortex
- grey matter

Interior
- white matter & nuclei

Attached to brain stem via cerebellar peduncles

Question 22

whats the cerebellar function

Answer 22

Receives wide range of sensory input

Co-ordinates skeletal muscles:
- Maintenance of normal muscle tone
- Regulates posture and balance

Functions noticeable after excessive alcohol intake
- ataxia = lack of muscle co-ordination

Question 23

describe ageing in terms of the brain

Answer 23

Rapid growth during first few years

Size of neurons & proliferation of neuroglia

Increases development of dendritic branches & synaptic contacts

Decline in brain mass from early adulthood onwards.