Topography of the brain

Question 1

what are the 4 basic topographic areas of the brain

Answer 1

brainstem
diencephalon
cerebellum
cerebrum

Question 2

what are the three parts of the brainstem

Answer 2

midbrain
pons
medulla

Question 3

what are the functions of the brainstem

Answer 3

1. provides a pathway for fibre tracts running between higher and lower centres
2. brainstem nucleii are involved in CN III-XII - so innervation of the head and neck
3. brainstem centres produce the rigidly programmed automatic behaviours essential for life e.g. cardioresp centres

Question 4

what is the cavity in the medulla

Answer 4

IV ventricle

Question 5

what is the medulla a continuation of (from below)

Answer 5

the spinal cord at the foramen magnum

Question 6

what are the surface features of the medulla

Answer 6

pyramids medially and their decussation (crossing over)

olives laterally

inferior cerebellar peduncle to connect to cerebellum

Question 7

what cranial nerves come from the surface of the medulla

Answer 7

IX, X, XI, XII

Question 8

what is the structure of the caudal and cranial medullary sections in terms of the IV ventricle

Answer 8

caudal - closed around IV ventricle

cranial - open with IV ventricle posteriorly

Question 9

what is contained in the white matter of the medulla

Answer 9

pyramidal tracts (motor)

medial lemniscus (sensory)

inferior cerebellar peduncle

+ other tracts

Question 10

what is contained in the grey matter of the medulla

Answer 10

cranial nerve nucleii

inferior olivary nucleus

nucleii of Reticular formation (vital centres)

sensory nucleii (gracile and cuneate)

Question 11

where is the IV ventricle in relation to the pons

Answer 11

posterior

Question 12

what are the surface features of the pons

Answer 12

middle cerebellar peduncle

Question 13

what cranial nerves come from the surface of the pons

Answer 13

V, VI, VII, VIII

Question 14

what is contained in the white matter of the pons

Answer 14

middle cerebellar peduncle

medial lemniscus (sensory)

pyramidal tract (motor)

Question 15

what is contained in the grey matter of the pons

Answer 15

cranial nerve nucleii

pontin nucleii

uncle of reticular formation

Question 16

what is the central cavity in the midbrain

Answer 16

cerebral aqueduct

Question 17

what are the surface feature of the midbrain

Answer 17

cerebral peduncle

superior cerebellar peduncle

superior and inferior colliculus

Question 18

what cranial nerves come from the surface of the midbrain

Answer 18

III, IV

Question 19

what is different about the origin site of CN IV compared to the others arising from the brainstem

Answer 19

the only one to originate posteriorly

Question 20

what is the structure of the cerebellum

Answer 20

right and left hemispheres separated by the vermis

Question 21

what is the structure of each cerebellar hemisphere

Answer 21

3 lobes - anterior, posterior, flocculonodular

Question 22

what connects the cerebellum to the brainstem

Answer 22

3 cerebellar peduncles - inferior, superior, middle

Question 23

what is contained in the grey matter of the cerebellum

Answer 23

cortex - on surface

deep - nucleii

Question 24

what is contained in the white matter of the cerebellum

Answer 24

arbor vitae

cerebellar peduncles

Question 25

what are the functions of the cerebellum

Answer 25

posture maintenance | fine tuning motor activity

Question 26

what can an abnormality in the cerebellum cause and how can this be tested for

Answer 26

ataxia - loss of full control of bodily movements finger-nose test walking in a straight line

Question 27

where is the diencephalon found

Answer 27

deep within the cerebral hemispheres, around the II ventricle

Question 28

what are 3 paired structures to the diencephalon

Answer 28

thalamus hypothalamus (+pituitary) epithalamus (+pineal gland) (all mainly grey matter)

Question 29

what is the function of the thalamus

Answer 29

sensory relay station | processing sensory info at lateral nucleii

Question 30

where does the hypothalamus lie

Answer 30

below the thalamus, separated by hypothalamic sulcus

Question 31

what is the function of the hypothalamus

Answer 31

main visceral control centre - essential for homeostasis

Question 32

what are the homeostatic roles of the hypothalamus

Answer 32

autonomic Control Centre body temperature food intake water balance & thirst sleep-wake cycle control of endocrine system functioning

Question 33

what is the blood supply to the brain

Answer 33

two internal carotid arteries (ICA) two vertebral arteries

Question 34

what are the branches of the ICA and what do they supply

Answer 34

anterior (ACA), middle (MCA) and posterior communicating arteries (PComA) ACA and MCA supply large part of cerebral hemispheres

Question 35

what do the vertebral arteries join together to form

Answer 35

basilar artery on ventral surface of the brainstem

Question 36

what supplies the brainstem and cerebllum

Answer 36

branches coming off the basilar artery

Question 37

what supplies the posterior part of the cerebral hemispheres

Answer 37

posterior cerebral arteries - arising from end of basil artery

Question 38

what is the circle of willis

Answer 38

a continuous circle of blood vessels at the base of the brain branches of the ICA join with those of the opposite side and with the PCA (branch of the basilar artery)

Question 39

what protective feature does the circle of willis supply

Answer 39

protection against vaso-occlusion of large arteries

Question 40

what does the anterior cerebral artery supply

Answer 40

Medial aspect of cerebral hemispheres excluding Occipital lobe

Question 41

what does the middle cerebral artery supply

Answer 41

Lateral aspect of cerebral hemispheres

Question 42

what does the posterior cerebral artery supply

Answer 42

Inferior aspect of cerebral hemispheres and Occipital lobe.

Question 43

what is the venous drainage of the brain

Answer 43

superficial and deep veins drain into venous sinuses

Question 44

what do the venous sinuses lie between

Answer 44

between 2 layers of dura mater

Question 45

where do the dural venous sinuses ultimately drain

Answer 45

into the internal jugular veins

Question 46

what does the diencephalon develop from embryologically

Answer 46

diencephalic vesicle (part of the forebrain)

Question 47

what do the midbrain, pons and medulla develop from embryologically

Answer 47

midbrain - mesencephalon (midbrain) pons - metencephalon (hindbrain) medulla - myencephalon (hindbrain)