Topography of the Brain

Question 1

When do the ectoderm, mesoderm and endoderm become established during embryonic development?

Answer 1

By the beginning of the second week

Question 2

What germ layer gives rise to the nervous system in the adult?

Answer 2

Ectoderm

Question 3

The process of formation of the embryonic nervous system is known as

Answer 3

neurulation

Question 4

The dorsal midline ectoderm undergoes thickening to form the neural plate during which week of embryonic development?

Answer 4

Third week

Question 5

The lateral margins of the neural plate become elevated to form

Answer 5

neural folds on either side of the neural groove

Question 6

The neural folds become apposed and

Answer 6

fuse together, sealing the neural groove and forming neural tube

Question 7

What processes occur during transformation of the neural tube into the adult CNS?

Answer 7

Growth
Distortion
Cellular differentiation

Question 8

What part of the neural tube develops into the brain?

Answer 8

The rostral part

Question 9

What part of the neural tube develops into the spinal cord?

Answer 9

The caudal part

Question 10

The central cavity within the neural tube becomes the

Answer 10

central canal of the spinal cord and the ventricles of the brain

Question 11

The neural crests form the

Answer 11

sensory ganglia of spinal and cranial nerves and autonomic ganglia

Question 12

What three primary vesicles can be identified around the fifth week of embryonic development?

Answer 12

Prosencephalon
Mesencephalon
Rhomboencephalon

Question 13

The prosencephalon becomes the

Answer 13

cerebrum

Question 14

The telencephalon becomes the

Answer 14

two cerebral hemispheres

Question 15

The diencephalon becomes the

Answer 15

thalamus

Question 16

The mesencephalon becomes the

Answer 16

pons and cerebellum

Question 17

The myencephalon becomes the

Answer 17

medulla oblongata

Question 18

The brainstem consists of the

Answer 18

medulla, pons and midbrain

Question 19

The brainstem acts as a pathway for

Answer 19

fibre tracts running between higher and lower centres

Question 20

Brainstem centres produce

Answer 20

the rigidly programmed automatic behaviours essential for survival

Question 21

Where does the diencephalon lie?

Answer 21

Deep within the cerebral hemispheres, around the III ventricle

Question 22

What are the paired structures of the diencephalon?

Answer 22

Thalamus
Hypothalamus
Pituitary
Epithalamus

Question 23

What is the thalamus responsible for?

Answer 23

Processing sensory information, acts as a sensory relay

Question 24

What is the hypothalamus responsible for?

Answer 24

Visceral control centre, essential for overall homeostasis

Question 25

Give the homeostatic functions of the hypothalamus

Answer 25

``` Autonomic control centre Body temp. regulation Regulation of food intake Regulation of water balance and thirst Regulation of sleep-wake cycle Control of endocrine system functioning ```

Question 26

How do the common carotid arteries enter the skull to supply the brain?

Answer 26

Through the carotid canal (foramen lacerum)

Question 27

What branches does the ICA give off in the brain?

Answer 27

Anterior and middle cerebral and posterior communicating arteries

Question 28

What branches of the ICA supply a large part of the cerebral hemispheres?

Answer 28

Anterior and middle cerebral arteries

Question 29

How do the vertebral arteries enter the skull?

Answer 29

Through the foramen magnum

Question 30

The vertebral arteries join together to form

Answer 30

the basilar artery (on ventral surface of brainstem)

Question 31

The basilar artery ends at the level of the

Answer 31

midbrain, by dividing into two posterior cerebral arteries

Question 32

The two posterior cerebral arteries supply

Answer 32

the posterior part of the cerebral hemispheres

Question 33

What is the Circle of Willis?

Answer 33

Continous circle of arteries at the base of the brain

Question 34

What does the Circle of Willis protect against?

Answer 34

Vaso-occlusion of large arteries

Question 35

The superficial and deep veins of the brain drain into

Answer 35

venous sinuses between the two layers of dura mater

Question 36

The dural venous sinuses join together to drain into the

Answer 36

internal jugular veins

Question 37

The vertebrobasilar arteries supply

Answer 37

the posterior two-fifths of the cerebrum, part of cerebellum and brainstem

Question 38

The external carotid arteries supply

Answer 38

the face and scalp

Question 39

The internal carotid arteries supply

Answer 39

most of the anterior portion of cerebrum

Question 40

Any decrease in the flow of blood through one of the ICAs brings about

Answer 40

some impairment in the function of the frontal lobes which may result in numbness/weakness/paralysis of opposite side of body

Question 41

Because the carotid and vertebrobasilar arteries form a circle, if one of the main arteries is occluded then

Answer 41

the distal smaller arteries that it supplies can receive blood from the other arteries

Question 42

Stroke in the anterior cerebral artery results in

Answer 42

opposite leg weakness

Question 43

Stroke in the middle cerebral artery can result in

Answer 43

paralysis, sensory loss in opposite side, aphasia

Question 44

Weber's syndrome results from occlusion of what arteries?

Answer 44

Posterior cerebral