Head and Neck 3-4 Quiz 2

What is the main arterial source of systemic circulation to the head and upper extremities in this lecture?

The aortic arch.

What are the three major branches of the aortic arch shown in the slides, from right to left?

Brachiocephalic trunk, left common carotid artery, and left subclavian artery.

What two major arteries arise from the brachiocephalic trunk?

The right common carotid artery and the right subclavian artery.

Which artery arises directly from the aortic arch to supply the left side of the head and neck?

The left common carotid artery.

Which subclavian artery arises directly from the aortic arch?

The left subclavian artery.

Approximately what percentage of blood to the brain is brought by the carotid arteries according to the lecture?

About 80%.

Approximately what percentage of blood to the brain is brought by the vertebral arteries according to the lecture?

About 20%.

What is the general function of the external carotid artery?

It supplies most structures external to the cranium, including superficial arteries and arteries of the face.

Which major carotid artery primarily supplies structures outside the cranium?

The external carotid artery.

Which major carotid artery enters the cranial cavity to deliver blood to the brain?

The internal carotid artery.

Which external carotid artery branches are labeled on the scalp/face diagram?

Superficial temporal, posterior auricular, occipital, maxillary, facial, transverse facial, lateral nasal, superior and inferior labial, angular, and mental arteries.

Which two arteries on the external-carotid slide are marked as exceptions because they originate from the internal carotid artery?

The supraorbital and supratrochlear arteries.

Through what opening does the internal carotid artery enter the cranial cavity?

The carotid canal.

What is the purpose of the internal carotid artery after entering the cranial cavity?

To deliver blood to the brain.

After passing through the carotid canal, the internal carotid artery passes superiorly toward what opening?

Foramen lacerum.

How does the lecture describe the foramen lacerum?

It is cartilage-filled and allows several small nerves and arteries to pass.

Near what major visual structure does the internal carotid artery course according to the slide?

Near the optic chiasm.

What endocrine structure lies next to the internal carotid artery in the region shown on the slides?

The pituitary gland.

What bony structure protects the pituitary gland?

The sella turcica of the sphenoid bone.

From what arteries do the vertebral arteries arise?

The right and left subclavian arteries.

Through which cervical vertebral levels do the vertebral arteries ascend in the neck according to the lecture?

Through the transverse processes from C6 to C1.

Which vertebral artery is usually larger according to the lecture?

The left vertebral artery.

Through what opening do the vertebral arteries enter the cranial cavity?

The foramen magnum.

What happens to the two vertebral arteries superiorly?

They join together to form the basilar artery.

What does each vertebral artery give rise to before forming the basilar artery?

A posterior inferior cerebellar artery (PICA).

What does PICA stand for?

Posterior Inferior Cerebellar Artery.

What structures are supplied by PICA according to the lecture?

The medulla and inferior parts of the cerebellum.

Which artery supplies the medulla and inferior cerebellum in this lecture?

PICA.

What artery is formed when the right and left vertebral arteries unite?

The basilar artery.

What major cerebellar branch arises from the basilar artery?

The anterior inferior cerebellar artery (AICA).

What does AICA stand for?

Anterior Inferior Cerebellar Artery.

What does AICA supply according to the lecture?

The inferior pons and parts of the inferior and anterior cerebellum.

Which artery supplies the inferior pons and parts of the inferior/anterior cerebellum?

AICA.

With which arteries does AICA form anastomoses according to the lecture?

PICA and the superior cerebellar artery.

What does the superior cerebellar artery supply according to the lecture?

The superior cerebellum.

What is an anastomosis?

A connection in which two or more different blood vessels unite.

What small arteries arise from the basilar artery between AICA and the superior cerebellar arteries?

Pontine arteries.

What do the pontine arteries mainly supply?

The pons.

Which artery is the source of the pontine arteries?

The basilar artery.

How does the basilar artery end?

It bifurcates into the two posterior cerebral arteries.

What does PCA stand for?

Posterior Cerebral Artery.

What does the posterior cerebral artery supply according to the lecture?

The inferior surface of the cerebral hemisphere, the occipital lobe, and the cerebral peduncles of the midbrain.

Which cerebral artery supplies the occipital lobe according to the lecture?

The posterior cerebral artery.

Which cerebral artery supplies the inferior surface of the cerebral hemisphere according to the lecture?

The posterior cerebral artery.

Which midbrain structure is supplied by the posterior cerebral artery along with the posterior communicating artery?

The cerebral peduncle.

What part of the Circle of Willis is formed by the posterior cerebral arteries according to the lecture?

The inferior part of the cerebral arterial circle.

What is another name for the cerebral arterial circle?

The Circle of Willis.

Why is the Circle of Willis historically named that way?

It is named after Dr. Thomas Willis, who first described the anatomical structure in 1664.

How does the lecture describe the Circle of Willis in terms of anastomosis?

It is the most important anastomosis of the brain.

With what arteries do the posterior cerebral arteries anastomose?

The posterior communicating arteries.

From what major artery do the posterior communicating arteries arise according to the lecture?

The internal carotid arteries.

What structures are listed as being supplied by the posterior communicating arteries?

Optic tract, cerebral peduncle, internal capsule, and thalamus.

Which artery connects the internal carotid circulation with the posterior cerebral artery in the Circle of Willis?

The posterior communicating artery.

After passing through the carotid canal, what cerebral artery does the internal carotid give rise to?

The anterior cerebral artery.

Distal to the anterior cerebral artery, what other major branch arises from the internal carotid artery?

The middle cerebral artery.

What does MCA stand for?

Middle Cerebral Artery.

What does the middle cerebral artery supply according to the lecture?

The temporal lobe and lateral surface of the cerebral hemispheres.

Which cerebral artery supplies much of the lateral surface of the cerebral hemisphere?

The middle cerebral artery.

Which cerebral artery supplies the temporal lobe according to the lecture?

The middle cerebral artery.

What does ACA stand for?

Anterior Cerebral Artery.

From what artery does the anterior cerebral artery originate?

The internal carotid artery.

What areas does the anterior cerebral artery supply according to the lecture?

The central surface of the cerebral hemisphere and the frontal lobe.

Which artery supplies the central surface of the cerebral hemisphere according to the lecture?

The anterior cerebral artery.

Which artery supplies the frontal lobe according to the lecture?

The anterior cerebral artery.

What artery connects the right and left anterior cerebral arteries?

The anterior communicating artery.

What is the function of the anterior communicating artery in the Circle of Willis?

It forms an anastomosis between the right and left anterior cerebral arteries.

Which five artery names are emphasized on the Circle of Willis summary slide?

Posterior cerebral, middle cerebral, anterior cerebral, posterior communicating, and anterior communicating arteries.

Which artery of the Circle of Willis links the right and left anterior cerebral arteries?

Anterior communicating artery.

Which paired arteries connect the internal carotid circulation with the posterior cerebral arteries?

Posterior communicating arteries.

Which two major circulatory sources ultimately contribute to the Circle of Willis?

The internal carotid circulation and the vertebral-basilar circulation.

Why is the Circle of Willis important?

It provides collateral circulation.

What is collateral circulation in the context of the Circle of Willis?

If a major vessel becomes narrowed or blocked, blood may still circulate through alternate connected vessels in the brain.

How can the Circle of Willis help during ischemia?

Its collateral circulation can provide an alternate route for blood flow when a major vessel is narrowed or blocked.

How can the Circle of Willis affect stroke damage according to the lecture?

It can provide some protection by reducing the severity or extent of damage.

Approximately what percentage of people have the classic complete Circle of Willis according to the lecture?

About 30–50%.

What does the lecture emphasize about the anatomy of the Circle of Willis?

There is a lot of anatomical variation.

What structures should you be able to identify on the contrast MRI of the Circle of Willis shown in the lecture?

Vertebral arteries, internal carotid arteries, sella turcica area, basilar artery, pontine arteries, anterior cerebral artery, right PICA, anterior communicating artery, right/left superior cerebellar arteries, left AICA, middle cerebral arteries, posterior cerebral arteries, and posterior communicating arteries.

Which vessels on the lecture MRI are described as very faint?

The pontine arteries.

Which cerebellar artery is specifically labeled on the right side in the MRI exercise?

Right PICA.

Which cerebellar artery is specifically labeled on the left side in the MRI exercise?

Left AICA.

What is an aneurysm according to the lecture?

A weakening of an arterial wall that causes thinning and bulging of the vessel wall.

What other name does the lecture use for this type of aneurysm?

Berry aneurysm.

What can happen if a cerebral aneurysm ruptures?

It can cause a brain bleed and death.

According to the lecture, where is the most common location of a brain aneurysm?

The Circle of Willis.

What percentage of brain aneurysms are said in the lecture to occur in the Circle of Willis?

About 85%.

Does the lecture give one definite cause of brain aneurysms?

No. It says the cause is unknown, but there are certain risk factors.

What aneurysm risk factors are listed in the lecture?

Atherosclerosis, family history, high blood pressure as a factor in rupture, and cigarette smoking.

How does the lecture define atherosclerosis?

Hardening of arteries due to cholesterol plaque buildup.

What blood-pressure-related factor is listed in connection with aneurysm rupture?

High blood pressure (HBP).

What smoking-related risk factor is listed for aneurysms?

Cigarette smoking.

Trace the posterior circulation pathway from the subclavian artery to the posterior cerebral artery.

Subclavian artery → vertebral artery → basilar artery → posterior cerebral artery.

Trace the vertebral-basilar cerebellar branches emphasized in the lecture.

Vertebral artery gives rise to PICA; the vertebral arteries unite as the basilar artery; the basilar gives rise to AICA, pontine arteries, and superior cerebellar branches before ending as the posterior cerebral arteries.

Trace the major anterior circulation pathway from the aortic arch to the right internal carotid artery.

Aortic arch → brachiocephalic trunk → right common carotid artery → internal carotid artery.

Trace the major anterior circulation pathway from the aortic arch to the left internal carotid artery.

Aortic arch → left common carotid artery → internal carotid artery.

What are the major intracranial branches of the internal carotid emphasized in the lecture?

Posterior communicating artery, anterior cerebral artery, and middle cerebral artery.

What are the main cerebral territories emphasized for ACA, MCA, and PCA?

ACA: central/medial surface and frontal lobe; MCA: temporal lobe and lateral cerebral surface; PCA: inferior cerebral surface and occipital lobe.

What are the meninges?

Three protective connective tissue membranes that cover the CNS, meaning both the brain and spinal cord.

What are the three cranial meninges from superficial to deep?

Dura mater, arachnoid mater, pia mater.

Which meningeal layer is the most superficial?

Dura mater.

Which meningeal layer is the middle layer?

Arachnoid mater.