Blood Supply To The Brain

Question 1

What is the blood supply to the brain?

Answer 1

Branches from:
Internal Carotid artery
Vertebro-Basilar artery

Question 2

What is the role of the internal carotid artery?

Answer 2

Provides the anterior circulation to the brain. It enters the cranial fossa by travelling in the carotid canal, which begins with an external opening on the temporal bone.

Question 3

What are the branches of the internal carotid artery?

Answer 3

Ophthalmic artery
Anterior cerebral artery
Middle cerebral artery
Posterior communicating artery

Question 4

What does the anterior cerebral artery supply?

Answer 4

Courses above the corpus callous to supply majority of the medial cerebral hemispheres of the frontal, parietal and temporal lobes. Laterally, it supplies the most superior portions of the frontal, temporal and parietal

Question 5

What does the middle cerebral artery supply?

Answer 5

Majority of the blood supply to the medial cerebral hemispheres EXCEPT superior portion of frontal, parietal and temporal lobes.

Question 6

What is the origin and course of the vertebrobasilar artery?

Answer 6

It is a branch of the subclavian artery. The vertebral artery passes through the transverse foramen of the vertebrae to enter the skull via the foramen magnum. It joins with the opposite vertebral artery to form the basilar artery. This artery provides the posterior circulation to the brain.

Question 7

What is the role of the anterior spinal artery?

Answer 7

Major blood supply to the anterior 2/3 of the spinal cord

Question 8

What is the role of the posterior inferior cerebellar artery?

Answer 8

It is a branch of the vertebral-basilar artery which supplies the inferior region of cerebellum and portions of the medulla and choroid plexus of 4th ventricle.

Question 9

What does the posterior cerebral artery supply?

Answer 9

Supplies the occipital lobe and posterolateral portions of the temporal lobe.

Question 10

What are the branches of the vertebrobasilar artery?

Answer 10

Posterior cerebral artery
Superior cerebellar artery
Anterior inferior cerebellar artery
Posterior inferior cerebellar artery
Anterior spinal artery

Question 11

What passes between the posterior cerebral artery and the superior cerebellar artery?

Answer 11

Cranial Nerve III: Oculomotor.

Question 12

What separates the anterior and middle cranial fossa?

Answer 12

Lesser wing of sphenoid bone.

Question 13

What separates the middle and posterior cranial fossa?

Answer 13

Petrous part of temporal bone.

Question 14

What is the Calvarium?

Answer 14

Bones of the skull which cover the brain.

Question 15

Which structures are present in the optic canal?

Answer 15

Cranial Nerve II: Optic Nerve
Opthalmic artery

Question 16

Which structures are present in the superior orbital fissure?

Answer 16

Passageway for innervation to extraoculomotor muscles:

Cranial Nerve III: Oculomotor nerve
Cranial Nerve IV: Trochlear nerve
Cranial Nerve V: Opthalmic branch/V1
Cranial Nerve VI: Abducens nerve

Question 17

Which structures are present in the foramen rotundum?

Answer 17

Contains the maxillary nerve, a branch of the Cranial Nerve V2: Trigeminal nerve.

Question 18

Which structures are present in the foramen ovale?

Answer 18

Branch of trigeminal nerve V3: Mandibular nerve.

Question 19

Which structures are present in the foramen spinosum?

Answer 19

Contains the middle meningeal artery which runs deep to the Pterion. Damage to the exterior results in an epidural haematoma.

Question 20

Which structures pass through the foramen lacerum?

Answer 20

Greater petrosal nerve branch of CN VII: the facial nerve which innervates the lacrimal gland.

Question 21

Which structures are present in the internal acoustic meatus?

Answer 21

Located in the petrous part of temporal bone and contains:
Cranial Nerve VIII: Vestibulocochlear nerve
Cranial Nerve VII: Facial Nerve

Question 22

Which structures are present in jugular canal?

Answer 22

Internal jugular vein
Cranial Nerve IX: Glossopharyngeal
Cranial Nerve X: Vagus nerve
Cranial Nerve XI: Spinal accessory

Question 23

Which structures are present in the hypoglossal canal?

Answer 23

Hypoglossal nerve

Question 24

What is the course for the facial nerve?

Answer 24

Passes through the internal acoustic meatus to exit the skull at the stylomastoid foramen and passes through the parotid gland gait give off the facial nerve proper.

Question 25

What are the contents of the foramen magnum?

Answer 25

Spinal cord
Vertebral arteries and anterior spinal arteries
Cranial Nerve XI: Spinal accessory nerve.

Question 26

Which structures are present in the cavernous sinus?

Answer 26

Internal carotid artery
CN III: Oculomotor
CN IV: Trochlear
CN V1: Opthalmic branch of trigeminal
CN VI: Abducens

Question 27

What are the dural venous sinuses formed of?

Answer 27

Located between the periosteum and dura mater and formed of the dura mater, lined with endothelium. It lacks any valves or a tunica media so blood is free flowing and goes through the sigmoid sinus to the internal jugular vein -> brachiocephalic vein to the R side of the heart.

Question 28

What is the cerebral aqueduct?

Answer 28

Flow of CSF between the 3rd and 4th ventricle.

Question 29

Which part of the ventricular system is connected to the subarachnoid space?

Answer 29

4th ventricle lateral and medial apertures.

Question 30

Where is the foreman spinosum located?

Answer 30

Sphenoid bone.