Lesson 3: Blood Supply

Question 1

What is a watershed area?

Answer 1

Has irrigation from multiple arteries

Question 2

What arteries branch off of the vertebral arteries before the basilar artery?

Answer 2

The anterior spinal artery, posterior spinal arteries, and the posterior inferior cerebellar arteries

Question 3

What branches off of the basilar artery?

Answer 3

The posterior cerebral arteries, the superior cerebellar artery, and the anterior and posterior inferior cerebellar arteries

Question 4

Where do the posterior arteries irrigate? What structure of the diencephalon?

Answer 4

Most of the temporal lobe, all of the occipital lobe, and the inferior surface of the brain. Also the thalamus

Question 5

Where does the superior cerebellar artery irrigate?

Answer 5

Pons through its pontine branches

Question 6

What is the role of the posterior communicating arteries?

Answer 6

Connect the internal carotid arteries with the vertebral arteries

Question 7

Where does the MCA irrigate (one structure in particular)? Why do we care about it (2 things)?

Answer 7

Lateral areas of the brain, and the internal capsule. It has lenticulostriate branches deeper into the brain, and is important to communication disorders.

Question 8

What are structures like the Circle of Willis called?

Answer 8

Anastomoses

Question 9

What is the role of the anterior communicating artery?

Answer 9

It connects the left and right anterior cerebral arteries

Question 10

What arteries are considered in the Circle of Willis?

Answer 10

Anterior and posterior communicating arteries, and the anterior and posterior cerebral arteries

Question 11

Where does the posterior cerebral artery branch off?

Answer 11

From the basilar artery and part of the Circle of Willis

Question 12

What irrigates the spinal cord?

Answer 12

The anterior spinal artery and the posterior spinal arteries, which is backed up by additional small branches from the aorta throughout the spine

Question 13

What structure gives way to the venous sinuses?

Answer 13

The infoldings of dura mater - falx cerebri, falx cerebelli, and tentorium cerebelli

Question 14

What is the process of blood back to the heart?

Answer 14

From the capillaries, to the cerebral veins, to the venous sinuses, to the internal jugular veins, to the heart

Question 15

What is the process of the superior sagittal sinus back to the heart?

Answer 15

To the right transverse sinus, to the right sigmoid sinus, to the right internal jugular vein

Question 16

What is the process of the inferior sagittal sinus?

Answer 16

To the straight sinus, to the left transverse sinus, to the left sigmoid sinus, to the left internal jugular vein

Question 17

What is the process of the cavernous sinus?

Answer 17

Into the sigmoid vein

Question 18

Why is shaken baby syndrome especially bad? What two types of injury does it consist of?

Answer 18

Both major trauma and axonal injury

Question 19

What is a coup injury?

Answer 19

Injury to the area where the skull impacted the brain, causing direct damage

Question 20

What is a contre-coup injury?

Answer 20

Backlash - the accelerating brain hits the opposite side of skull

Question 21

What is an uncal herniation?

Answer 21

Compression of the uncus (parahippocampal gyrus) against the tentorial notch

Question 22

What is a tonsillar herniation?

Answer 22

Compression of the brainstem and cerebellum into the foramen mangum

Question 23

What is the difference between a hematoma and a hemorrhage?

Answer 23

A hemorrhage; higher pressure, rapid - more often arterial bleeding
A hematoma: pooling of blood that occupies space - more often venous injury

Question 24

Where is an epidural hemorrhage, and what is bleeding? What is often its cause, and how urgent is it?

Answer 24

From the middle meningeal artery - rapid arterial bleeding between the skull and periosteal dura. It’s urgent, and associated with skull fracture. Frequently due to a fracture of the pterion.

Question 25

What causes a subdural hematoma, and where does it occur? How urgent is it? What is the nature of the symptoms?

Answer 25

Between the dura and arachnoid mater - venous bleeding.
Symptoms are transient - hematoma may shift along the subdural space. It is less urgent, since it’s slower - but still dangerous.

Question 26

What in particular often causes a subarachnoid hemorrhage, and where does it occur? What type of bleeding is it, and what is often the cause of the underlying condition? What are some early symptoms?

Answer 26

In the subarachnoid space, between the arachnoid mater and the pia mater. A rupture aneurysm in the Circle of Willis - arterial bleeding by a congenital defect. Warning signs include intense headaches, and oculomotor nerve damage.

Question 27

What can be a consequence of a subarachnoid hemorrhage, due to its location?

Answer 27

It can bleed into the subarachnoid space, and mix with the cerebrospinal fluid, and thus clot and cause issues

Question 28

What often causes an intracerebral hemorrhage, and what are the possible underlying causes of this condition? Where do they occur?

Answer 28

Ruptured arteries in the brain, often due to a TBI or hemorrhagic stroke. It occurs within the cerebrum.

Question 29

What is a non-vascular head injury?

Answer 29

Trauma to the blood vessels that causes a space-occupying lesions

Question 30

What is a vascular head injury?

Answer 30

Loss of circulation to the brain tissue itself