The brain 13

Question 1

what does the brains blood supply require?

Answer 1

• 20% of bodys oxygen supply - 4 mins lack of oxygen equals permanent damage.
  *requires continuous glucose supply.

Question 2

the brains blood supply is protected by a blood brain barrier, what does it allow through the barrier?

Answer 2

It allows lipid soluble materials - O2, CO2 , alcohol, anaesthetic agents but controls entry of everything else.

Question 3

what creates the brains blood supply?

Answer 3

tight capillaries and glial cells - astrocytes.

Question 4

what does the brain stem contain?

Answer 4

medulla oblongata (small bump), pons (larger bump), midbrain.

Question 5

what does the brain stem connect with?

Answer 5

Spinal chord.

Question 5

what is the medulla oblongata (part of brain stem) made up of?

Answer 5

White matter extending between spinal cord and other parts of brain.

Question 6

medulla oblongata contains several nuclei/clusters of cell bodies, what are the 3 vital reflex centres?

Answer 6

Cardiovascular centre (heart rate),
medullary rhythmicity area (respiratory rhythm)
and vasomotor (vasoconstriction)
other sensory, reflex motor areas eg sneezing, vomiting.

Question 7

What does pons (part of brain stem) do ?

Answer 7

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

Question 8

Do nerve tracts cross at the pons (brain stem)?

Answer 8

Yes, 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

what does the midbrain (brain stem) connect together?

Answer 9

Connect pons to diencephalon.

Question 10

what does the midbrain do? (brain stem)

Answer 10

• conveys motor impulses from cerebrum to cerebellum and spinal cord.
  *conveys sensory impulses from spinal cord to thalamus

Question 11

what does the midbrain contain?

Answer 11

contains the substantial nigra - areas affects by Parkinson’s disease - dopamine.

Question 12

What are the 4 major areas of the brain?

Answer 12

Brain stem, diencephalon, cerebrum, cerebellum.

Question 13

Diencephalon is found above the brain stem, what is included?

Answer 13

Thalamus, hypothalamus, and pineal gland - melatonin

Question 14

what does the thalamus (diencephalon) do?

Answer 14

transmits motor information from cerebellum and basal nuclei to cerebrum.

Question 15

Hypothalamus (important for homeostasis), has 6 functions what are they?

Answer 15

1) control of ANS-regulation of many activities.
2) control of pituitary and hormone production.
3) regulation of emotional and behaviour patterns.
4) regulation of eating and drinking
5) control of body temperature.
6)regulation of circadian rhythms and states of consciousness.

Question 16

what does the pineal gland (diencephalon) do ?

Answer 16

Secretes melatonin which promotes sleep.

Question 17

cerebrum is at the top of brain and largest part, what is it made up of?

Answer 17

surface covered with grey matter, cerebral cortex

beneath is cerebral white matter

Question 18

explain the cerebrum structure.

Answer 18

-cerebral cortex - grey matter/cell bodies
-internal white matter
-surface folds - gyri/gyrus
- grooves between-sulci/sulcus
-longitudinal fissure- dvivides into left and right hemispheres
- connected by corpus callosum.

Question 19

what do motor areas of the brain do?

Answer 19

initiate movements.

Question 20

what do sensory areas of the brain do?

Answer 20

receive input and responsible for perception.

Question 21

what do associative areas of the brain do?

Answer 21

complex integration eg memory, emotion, reasoning.

Question 22

what are the four cerebral hemisphere lobes ?

Answer 22

frontal, parietal, temporal, occipital

Question 23

what is the right side of cerebrum important for?

Answer 23

spatial and pattern recognition and emotional content.

Question 23

what is the left side of cerebrum important for?

Answer 23

spoken and written language, numerical and scientific skills and reasoning.

Question 23

cerebellum is found back of the brain, what does it mean?

Answer 23

means little brain.

Question 24

what is the cerebellum made up of?

Answer 24

2 cerebellar hemispheres - posterior to medulla and pons, below cerebrum.
cerebellar cortex - grey matter
interior - white matter and nuclei
attached to brain stem via cerebellar peduncles.

Question 25

what is the function of the cerebellar?

Answer 25

receives range of sensory input.
coordinates skeletal muscles - regulates posture and balance, maintains muscle tone.
Functions noticeable after excessive alcohol intake, ataxia, lack of muscle co-ordination.

Question 26

what happens in ageing of the brain?

Answer 26

rapid growth first few years,
age increases development of dendritic branches and synaptic contacts,
there is a decline in brain mass from early adulthood onwards.