Blood Supply

Question 1

Vascular System

Answer 1

Responsible for blood supply aka circulatory system.

Brain has tight regulatory control over delivery of O2 + glucose and removal of CO2

Question 2

2 arterial territories responsible of blood supply to the brain

Answer 2

Anterior and posterior cerebral circulation (2 of each)

Question 3

Circle of Willis

Answer 3

Provides overlapping/backup blood supply

• Anterior and posterior circulations (interconnected via bilateral posterior communicating arteries) are part of the circle of Willis

Question 4

Circle of Willis is an example of

Answer 4

An anastomosis that protects the brain when part of the vascular supply is blocked

Question 5

2 anterior cerebral arteries are connected by the __________.

Answer 5

Anterior communicating artery

Question 6

2 posterior cerebral arteries are connected to the __________ by the ___________.

Answer 6

Internal carotid arteries by the posterior communicating arteries

Question 7

3 main cerebral arteries:

Answer 7

1. Middle cerebral artery
2. Anterior cerebral artery
3. Posterior cerebral artery

Question 8

Anterior circulation includes:

Answer 8

1. Middle cerebral artery

2. Anterior cerebral artery

Question 9

Posterior circulation includes:

Answer 9

Posterior cerebral arteries

Question 10

Middle cerebral artery

Answer 10

Has superior and inferior divisions of cortical branches.

Takes indirect course through lateral sulcus, along insular cortex, and over the inner opercular surface of the frontal, temporal, and parietal lobes.

Question 11

Anterior cerebral artery

Answer 11

Courses within sagittal fissure and around rostral end of corpus Callosum

Question 12

Posterior cerebral artery

Answer 12

Courses through lateral part of the brain

Question 13

MCA supplies

Answer 13

Most of the lateral convexity of the cortex (except leg area of motor homunculus)

• deep structure get blood from branches of internal carotid artery and proximal positions of cerebral arteries
• gray matter of cerebral cortex and underlying white matter are supplied by branches of distal portions of cerebral arteries

Question 14

ACA supplies:

Answer 14

The cortex and white matter of medial frontal and parietal loves, and the anterior corpus callosum. A strip of cortex wide in later surface.

Question 15

PCA supplies

Answer 15

Occipital lobes and medial and inferior temporal lobes and posterior corpus callosum

Question 16

MCA - contralateral hemiparesis and hemisensory loss

Answer 16

Involving the face and arm (precentral and postcentral gyri)

Question 17

MCA - hemineglect (right hemisphere)

Answer 17

Unawareness of space and own body contralateral to lesion. Patients unaware or deny they’re handicap

Question 18

Parietalneglect syndrome

Answer 18

Failure to recognize side of body contralateral to injury. May not bathe contralateral side of body or shave contralateral side of face. Deny own limbs. Objects in contralateral visual field ignored.

Question 19

MCA - anosognosia

Answer 19

(Right hemisphere)

Unawareness of dramatic impairments like blindness or paralysis

Question 20

MCA - aphasia

Answer 20

(Left hemisphere)

Brock’s aphasias
Wernicke’s aphasias

Question 21

Brock’s aphasia

Answer 21

Difficulty producing speech. Can understand but not talk

Question 22

Wernicke’s aphasia

Answer 22

Difficulty comprehending speech. Can’t understand but can talk fluently, however their speech doesn’t make any sense.

Question 23

ACA - contralateral hemiparesis

Answer 23

Paralysis or weakness of one side of the body

Question 24

ACA - hemisensory loss

Answer 24

Involving leg and foot (paracentral lobule)

Question 25

ACA - frontal lobe

Answer 25

Personality changes

Question 26

PCA - occipital lobe: hemianopsia

Answer 26

Loss of vision for one half of the visual field

Question 27

PCA - occipital lobe: visual agnosia

Answer 27

Inability to recognize or interpret objects in the visual field

Question 28

PCA - temporal lobes

Answer 28

Memory impairment

Question 29

PCA - temporal lobes: prosopagnosia

Answer 29

Damage in occipital and temporal lobes - unable to identify the facial characteristics, may not recognize the face at all (face blinding) - aware that some visual stimulus is present - can describe particular aspects without difficulty - can discriminate subtle shape differences, recognize sex, age, and likability of faces - identify people by non-facial cues such as voice, body shape, gait

Question 30

Stroke

Answer 30

Death or dysfunction of brain tissue due to vascular disease

Question 31

Occlusive

Answer 31

Closure of a blood vessel - atherosclerosis and thrombosis

Question 32

Hemorrhagic

Answer 32

Bleeding from a vessel- hypertension and aneurysm

Question 33

Intraparenchymal hemorrhage

Answer 33

Within the brain

Question 34

Extraparenchymal hemorrhage

Answer 34

At the brain surface (subarachnoid)

Question 35

Hematoma

Answer 35

Accumulation of blood that clots

Question 36

Embolus

Answer 36

Material (blood clot, air, fat) carried from one point to lodge in another

Question 37

Embolism

Answer 37

Embolus becomes lodged in artery and obstruct flow

Question 38

Aneurysm

Answer 38

Balloon-like dwelling in wall of artery

Question 39

Ischemia

Answer 39

Insufficiency of blood supply

Question 40

Infarction

Answer 40

Neuronal death

Question 41

Venous drainage of cerebral hemispheres

Answer 41

- Superficial veins drain into super sagittal sinus and cavernous sinus - deep veins drain into great vein of Galen - superior sagittal sinus drains into the 2 transverse sinuses which lead to the sigmoid sinus that connects to the jugular vein