Week 9 - Supply to the Brain

Question 1

How much oxygen and glucose does the brain use up in a day?

Answer 1

25%, 20% respectively

Question 2

Grey matter and white matter

Answer 2

Grey matter is where the brain communicates, and cell bodies lie.

White matter helps connect other grey matter areas together. It is white due to the myelin sheath on the axons.

Question 3

Internal Carotid artery pathway and what does it supply?

Answer 3

Aorta -> Aortic arch -> common carotid -> bifurcates into internal and external -> enters brain through carotid canal.

Supplies anterior and middle brain.

Question 4

Vertebral artery pathway and what does it supply?

Answer 4

Aorta -> subclavian artery -> vertebral arteries (L) & (R) -> foramina in cervical vertebrae -> meet in pons -> foramen magnum -> basilar artery in brain -> posterior cerebral arteries.

Supplies posterior brain. Cerebellum, brainstem, Posterior Cerebrum.

Question 5

Clinical Question
Which artery is more likely to get a blood clot from atrial fibrillation - Carotid or Vertebral and why?

Answer 5

Carotid
The diameter of the carotid is wider than the vertebral and therefore have a higher likelihood of a blood clot entering a more turbulent wider artery.

Question 6

Clinical Question
Which artery would be more likely to become damaged in an extreme flexion manipulation “cracking” technique? - Carotid or Vertebral and why?

Answer 6

Vertebral
Vertebral are surrounded by bony structures in the vertebral foramen. Carotid does not have any bony structures nearby.

Question 7

What does the external carotid artery supply?

Answer 7

Face and scalp

Question 8

Circle of Willis contains which arteries?

Answer 8

Anterior, middle and posterior cerebral arteries, & anterior and posterior communicating arteries.

Question 9

What do the Lenticulostriate arteries supply?

Answer 9

Basal Ganglia - Collection of nuclei found deep within the cerebral hemispheres. They are primarily concerned with influencing movement.

Internal Capsule - a dense system of afferent and efferent fibres that carry sensory and motor information from/to the face and body.

Question 10

Which is the biggest cerebral artery and what arteries branch off this?

Answer 10

Middle cerebral artery

Lenticulostriate arteries

Question 11

Damage to Lenticulostriate arteries can cause what kind of symptoms?

Answer 11

Motor, sensory or mixed motor & sensory symptoms.

Question 12

What important arteries supply the Lenticulostriate arteries?

Answer 12

Anterior cerebral, posterior cerebral, internal carotid arteries.

Question 13

Name the artery that supplies the medial aspect of the frontal and parietal lobes.

Answer 13

The anterior cerebral artery (ACA) supplies the medial aspect of the frontal and parietal lobes.

Question 14

Which artery is responsible for supplying most of the lateral surface of the cerebral hemispheres?

Answer 14

The middle cerebral artery (MCA) is responsible for supplying most of the lateral surface of the cerebral hemispheres.

Question 15

What is the Circle of Willis and what is its function?

Answer 15

The Circle of Willis is a circulatory anastomosis that provides a collateral circulation for the brain. It ensures that blood supply is maintained to all parts of the brain, even if one part of the arterial input is blocked

Question 16

Which arteries form the basilar artery?

Answer 16

The two vertebral arteries join to form the basilar artery.

Question 17

Which artery supplies the occipital lobes and the inferior and medial temporal lobes?

Answer 17

The posterior cerebral artery (PCA) supplies the occipital lobes and the inferior and medial temporal lobes.

Question 18

What is the significance of the posterior communicating artery in the Circle of Willis?

Answer 18

The posterior communicating artery connects the internal carotid artery with the posterior cerebral artery, facilitating communication between the anterior and posterior circulations of the brain.

Question 19

How does the Circle of Willis protect against ischemic damage?

Ischemic definition - inadequate blood supply (circulation) to a local area due to blockage of the blood vessels supplying the area.

Answer 19

The Circle of Willis provides redundancy in the cerebral circulation, allowing for alternative routes of blood flow if one artery is blocked, thereby reducing the risk of ischemic damage.

Question 20

Which artery supplies the inferior surface of the cerebellum?

Answer 20

The Posterior Inferior Cerebellar Artery (PICA) supplies the inferior surface of the cerebellum.

Question 21

What area of the cerebellum does the Anterior Inferior Cerebellar Artery (AICA) supply?

Answer 21

The Anterior Inferior Cerebellar Artery (AICA) supplies the anterior part of the inferior surface of the cerebellum.

Question 22

Which artery is responsible for supplying the superior surface of the cerebellum?

Answer 22

The Superior Cerebellar Artery supplies the superior surface of the cerebellum.

Question 23

Name the artery that supplies the occipital lobes and the inferior and medial temporal lobes.

Answer 23

The Posterior Cerebral Artery (PCA) supplies the occipital lobes and the inferior and medial temporal lobes.

Question 24

Which artery, if blocked, could lead to coordination and balance issues due to its supply to the cerebellum?

Answer 24

A blockage in the superior cerebellar artery could result in coordination and balance issues (ataxia) because it supplies the superior surface of the cerebellum.

Question 25

What neurological deficits would likely result from an occlusion of the anterior inferior cerebellar artery (AICA)?

Answer 25

An occlusion of the anterior inferior cerebellar artery (AICA) could lead to vertigo, nausea, and nystagmus due to its role in supplying the anterior part of the inferior surface of the cerebellum, affecting the vestibular system.

Question 26

If the posterior inferior cerebellar artery (PICA) is occluded, what specific syndrome might result, and what are its symptoms?

Answer 26

Occlusion of the posterior inferior cerebellar artery (PICA) could lead to Wallenberg’s syndrome (lateral medullary syndrome), characterized by vertigo, ataxia, dysphagia, hoarseness, and contralateral loss of pain and temperature sensation.

Question 27

Which artery, when blocked, might result in difficulty speaking or understanding language, and why?

Answer 27

A blockage in the middle cerebral artery (MCA), particularly on the left side in most individuals, can lead to aphasia (difficulty in speaking or understanding language) because it supplies areas of the brain involved in language processing, such as Broca’s and Wernicke’s areas.

Question 28

What are the possible effects of an occlusion in the ophthalmic artery?

Answer 28

Occlusion of the ophthalmic artery can lead to sudden, painless vision loss in the affected eye because it supplies blood to the retina and other ocular structures.

Question 29

How could a blockage of the basilar artery affect the body, considering its anatomical supply?

Answer 29

A blockage in the basilar artery can lead to severe brainstem syndromes, including quadriplegia, loss of consciousness, and even locked-in syndrome, as it supplies blood to critical structures within the brainstem.