Blood Supply to the Nervous System

Question 1

which two paired arteries are responsible for the blood supply to the brain?

Answer 1

vertebral and internal carotid arteries

Question 2

describe the circle of Willis

Answer 2

the joining area for the internal carotid and vertebral arteries

Question 3

what is 9?

Answer 3

basilar artery

Question 4

what is 10?

Answer 4

labyrinthine artery

Question 5

what is 11?

Answer 5

anterior inferior cerebellar artery

Question 6

what is 12?

Answer 6

posterior inferior cerebellar artery

Question 7

what is 13?

Answer 7

vertebral artery

Question 8

what is 14?

Answer 8

anterior spinal artery

Question 9

from which arteries do the left and right vertebral arteries arise?

Answer 9

subclavian artery

Question 10

at what vertebral level do the left and right internal carotid arteries arise?

Answer 10

C4

Question 11

how is the basilar artery formed and which part of the brainstem is it most closely related to?

Answer 11

formed via joining of vertebral arteries and related to pons

Question 12

which arteries complete the posterior Circle of Willis by linking the internal carotid arteries to the posterior cerebral arteries?

Answer 12

posterior communicating artery (6 on diagram)

Question 13

which artery completes the anterior Circle of Willis by linking the anterior cerebral arteries?

Answer 13

anterior communicating artery (2 on diagram)

Question 14

identify the three cerebral arteries. In which fissure/groove/sulcus of the brain do they travel?

Answer 14

1. anterior cerebral artery > anterior and medial aspect of the median longitudinal fissure.
2. middle cerebral artery > travels from base of brain through lateral sulcus.
3. posterior cerebral artery > travels in calacrine fissure as calcarine artery.

Question 15

which artery/arteries supplies the primary motor cortex?

Answer 15

anterior and middle (mostly) cerebral arteries

Question 16

which artery/arteries supplies the primary sensory cortex?

Answer 16

middle cerebral artery

Question 17

which artery/arteries supplies the primary visual cortex?

Answer 17

calcarine artery branch of posterior cerebral artery

Question 18

which artery/arteries supplies the primary auditory cortex?

Answer 18

middle cerebral artery

Question 19

which artery/arteries supplies the area for olfaction?

Answer 19

anterior cerebral artery

Question 20

which parts of the brain does the vertebro-basilar system supply?

Answer 20

brainstem, occipital lobes, cerebellum

Question 21

which cerebral artery runs immediately superior to the superior cerebellar arteries?

Answer 21

posterior cerebral artery

Question 22

which cranial nerve emerges from just above the superior cerebellar artery?

Answer 22

oculomotor III

Question 23

what are the clinical manifestations of palsy of CN III?

Answer 23

• down and out ocular positioning with abduction, slight depression and intorsion.
• complete ptosis due to neuropathy affecting levator palpebrae superioris.

Question 24

describe the carotid sinus and its function

Answer 24

• a dilatation located on the terminal part of the CCA (or the proximal part of the ICA).
• pressure receptor which monitors the flow of blood to the head, including the brain.
• sensory nerves from the carotid sinus run in the glossopharyngeal and vagus nerve.

Question 25

describe the carotid body and its function

Answer 25

• an area on the posterior wall of the terminal part of the CCA in the neck.
• conains chemoreceptors which are sensitive to low oxygen levels (anoxia).
• sensory nerves from these receptors run in the glossopharyngeal nerve.
• detection of anoxia will stimulate increased heart rate, respiration rate and blood pressure.

Question 26

The brain is drained by a series of veins which drain into Dural venous sinuses. These sinuses are present between what structures?

Answer 26

the periosteum and the cranial dura

Question 27

what is the highlighted structure and what does it drain?

Answer 27

• superior sagittal sinus
• drains the superior cerebral veins

Question 28

label the larger intracranial venous sinuses

Answer 28

Question 29

into which vein do the dural venous sinuses drain into?

Answer 29

IJV

Question 30

the superior opthalamic vein drains into..

state for both within and outside cranial cavity

Answer 30

the cavernous sinus within the cranial cavity. On the outside of the cranial cavity, it is continous with the facial vein.

Question 31

describe emissary veins

Answer 31

Emissary veins are valveless venous structures that connect the extracranial vessels of the scalp to the intracranial dural venous sinuses and diploic veins.

Question 32

what veins drain into the cavernous sinus?

Answer 32

opthalamic veins
central vein of retina
sphenoparietal sinus
superficial middle cerebral vein
pterygoid plexus

Question 33

which structures on the skull base is the cavernous sinus closely related to?

Answer 33

sella turcica of the sphenoid bone (which the pituitary gland sits upon).

Question 34

branches from which arteries fuse to form the anterior spinal artery?

Answer 34

formed from branches of vertebral arteries

Question 35

which arteries are the posterior spinal arteries branches of?

Answer 35

posterior spinal arteries originate from the vertebral artery or the posteroinferior cerebellar artery

Question 36

which artery is A?

Answer 36

middle cerebral artery

Question 37

which artery supplies the medial surface of the parietal lobe?

Answer 37

anterior cerebral artery

Question 38

the vertebral arteries arise from which artery?

Answer 38

subclavian

Question 39

what venous sinus lies at A?

Answer 39

straight sinus