Cerebrovascular Evaluation And Anatomy

Question 1

What is the origin of the internal carotid artery?

Answer 1

common carotid artery

Question 2

Where does the internal carotid artery travel before giving off branches?

Answer 2

Into the base of the skull

Question 3

What is the first major branch of the internal carotid artery?

Answer 3

ophthalmic artery

Question 4

At what location does the ophthalmic artery branch off from the internal carotid artery?

Answer 4

At the carotid siphon

Question 5

Which arteries are given off by the internal carotid artery before it divides?

Answer 5

• Caroticotympanic branch
• Anterior choroidal artery
• Posterior communicating artery

Question 6

What does the internal carotid artery divide into?

Answer 6

• Middle cerebral artery
• Anterior cerebral artery

Question 7

What areas does the internal carotid artery distribute blood to?

Answer 7

• Anterior brain
• Eyes
• Forehead
• Nose

Question 8

What is the nature of the vascular bed supplied by the internal carotid artery?

Answer 8

Very low-resistance vascular bed

Question 9

What percentage of blood in the common carotid artery flows into the internal carotid artery?

Answer 9

70-80%

Question 10

Fill in the blank: The internal carotid artery satisfies the tremendous metabolic demands of the _______.

Answer 10

brain

Question 11

What is the origin of the external carotid artery?

Answer 11

Common carotid artery

The external carotid artery arises from the common carotid artery.

Question 12

How many branches does the external carotid artery give off?

Answer 12

Eight branches

These branches supply blood to the neck, face, and scalp.

Question 13

Name three branches of the external carotid artery.

Answer 13

• Superior thyroid artery
• Lingual artery
• Facial artery

These are examples of the branches supplying high-resistance vascular beds.

Question 14

Which artery is frequently visualized in carotid duplex evaluations?

Answer 14

Superior thyroid artery

Its visualization helps differentiate the external carotid artery from the internal carotid artery.

Question 15

True or False: The internal carotid artery typically has branches in the neck.

Answer 15

False

The internal carotid artery normally has no branches in the neck.

Question 16

What is the typical blood flow direction in the superior thyroid artery compared to the common carotid artery?

Answer 16

Retrograde

The blood flow in the superior thyroid artery is usually retrograde due to its course.

Question 17

Fill in the blank: The superior thyroid artery is usually the _______ branch of the external carotid artery.

Answer 17

first

It is typically the first branch but can sometimes originate from the distal common carotid artery.

Question 18

List five branches of the external carotid artery.

Answer 18

• Ascending pharyngeal artery
• Occipital artery
• Posterior auricular artery
• Superficial temporal artery
• Maxillary artery

These branches contribute to the vascular supply of the head and neck.

Question 19

What arteries originate from the subclavian arteries?

Answer 19

The right and left vertebral arteries

The right vertebral artery is usually smaller than the left.

Question 20

What happens to the right and left vertebral arteries after they enter the skull?

Answer 20

They unite to form the basilar artery

This occurs through the foramen magnum.

Question 21

What is formed by the confluence of the right and left vertebral arteries?

Answer 21

The basilar artery

Question 22

Into what arteries does the basilar artery divide?

Answer 22

The posterior cerebral arteries

Question 23

What part of the brain does the basilar artery supply blood to?

Answer 23

The posterior structures of the cranial cavity

Question 24

What is the circle of Willis?

Answer 24

An intracranial communication channel that connects the anterior and posterior circulatory systems

Question 25

What size is the circle of Willis approximately compared to a common object?

Answer 25

The size of a fifty-cent piece

Question 26

What does a complete circle of Willis provide?

Answer 26

An important collateral pathway for blood flow to the brain in cases of stenosis or occlusion

Question 27

True or False: The circle of Willis is always complete in all individuals.

Answer 27

False

Question 28

Fill in the blank: The right and left vertebral arteries are __________ in size.

Answer 28

asymmetrical

Question 29

What is the hexagonal arrangement of the distal internal carotid, anterior cerebral, and posterior cerebral arteries known for?

Answer 29

It is known for being interconnected by the anterior and posterior communicating arteries, which serve as collateral channels during significant lesions.

Question 30

What usually triggers blood flow through the anterior and posterior communicating arteries?

Answer 30

Blood flow through these arteries is usually evident only when they serve as collateral channels secondary to a hemodynamically significant lesion of the extracranial carotid circulation.

Question 31

What are some variations that can occur in the hexagonal arrangement of brain arteries?

Answer 31

Variations can include differences in vessel size and congenital anomalies.

Question 32

Which artery arises from the ophthalmic artery and travels anteriorly and superiorly to the globe?

Answer 32

The supraorbital artery.

Question 33

What is the function of the frontal artery?

Answer 33

It supplies the mid-forehead and exits the orbit medially.

Question 34

How does the supraorbital artery connect to the external carotid artery?

Answer 34

It joins via branches of the superficial temporal artery.

Question 35

How does the frontal artery connect to the external carotid artery?

Answer 35

It joins via various branches, such as the superficial temporal artery.

Question 36

Fill in the blank: The major branches of the ophthalmic artery that exit the orbit include the _______ and the frontal artery.

Answer 36

supraorbital artery

Question 37

True or False: The periorbital circulation includes branches that do not connect to the external carotid artery.

Answer 37

False

Question 38

What is the nasal artery and its function?

Answer 38

Branches from the frontal artery to supply the nose and becomes the angular artery.

Question 39

What does the nasal artery join?

Answer 39

Joins the external carotid artery via the facial artery.

Question 40

What is the largest interarterial connection in the brain?

Answer 40

Circle of Willis.

Question 41

What are intracranial-extracranial anastomoses?

Answer 41

Connections between the internal carotid artery and external carotid artery.

Question 42

Name one connection between the ICA and external carotid artery.

Answer 42

Ophthalmic and orbital arteries.

Question 43

Which artery connects the occipital branch of the external carotid artery?

Answer 43

Atlantic branch of the vertebral artery.

Question 44

What branches connect to the lower vertebral artery?

Answer 44

Deep cervical and ascending cervical branches of the subclavian.

Question 45

What do small intraarterial communications include?

Answer 45

Intricate network of transdural anastomoses.

Question 46

What forms the meningeal border-zone network?

Answer 46

Leptomeningeal collaterals.

Question 47

What is the primary function of arteries?

Answer 47

To carry blood away from the heart.

Question 48

What substances do arteries transport?

Answer 48

Gases, nutrients, and other essential substances.

Question 49

How do arteries help regulate blood flow?

Answer 49

By contracting and relaxing.

Question 50

What are the three layers of blood vessels?

Answer 50

Tunica intima, tunica media, tunica adventitia.

Question 51

What is the tunica intima?

Answer 51

The inner layer of blood vessels consisting of endothelial cells.

Question 52

What is the tunica media composed of?

Answer 52

Smooth muscles and collagenous fibers.

Question 53

What is the role of the tunica adventitia?

Answer 53

Outermost layer providing structural support.

Question 54

Fill in the blank: The tunica intima is made of a single layer of _______.

Answer 54

endothelial cells.

Question 55

What are the vasa vasorum?

Answer 55

The 'vessels of vessels' that supply blood to the walls of larger arteries ## Footnote They transport oxygen and nutrients and remove waste products.

Question 56

What is the primary function of the vasa vasorum?

Answer 56

To supply blood to the walls of larger arteries and maintain patency of the internal carotid artery in focal occlusion ## Footnote They can also serve as collateral pathways.

Question 57

What does the Bernoulli principle state?

Answer 57

Total fluid energy along a streamline is constant, with velocity energy and pressure energy being inversely proportional ## Footnote Higher velocity results in lower pressure and vice versa.

Question 58

What develops as a result of changes in vessel geometry and direction?

Answer 58

Pressure gradients ## Footnote These gradients can lead to areas of flow separation and reversed flow.

Question 59

What does Poiseuille's law describe?

Answer 59

Flow through a rigid tube as being parabolic or laminar ## Footnote It relates flow to various factors like pressure gradient, vessel radius, viscosity, and length.

Question 60

According to Poiseuille's law, flow (Q) is directly proportional to which factors?

Answer 60

* Pressure gradient (P) * Radius of the vessel (r) ## Footnote Flow increases with higher pressure gradients and larger vessel sizes.

Question 61

According to Poiseuille's law, flow (Q) is inversely proportional to which factors?

Answer 61

* Viscosity of the fluid (n) * Length of the vessel (L) ## Footnote Higher viscosity and longer vessel lengths increase resistance, reducing flow.

Question 62

What is the mathematical relationship of flow (Q) in Poiseuille's law?

Answer 62

Q = (P * r^4) / (8 * n * L) ## Footnote The radius (r) is raised to the fourth power, indicating significant sensitivity to changes in radius.

Question 63

True or False: Small changes in the radius of a vessel lead to large changes in flow.

Answer 63

True ## Footnote This is due to the radius being raised to the fourth power in the flow equation.