Slpa 853 - Neurology - Blood Supply

Front 1

What is the function of the blood flow to the brain?

Back 1

-provides O2 and glucose
-removes toxic metabolite

Front 2

What is the effect of disruption of blood flow?

Back 2

-stroke/ CVA refers to the neurological symptoms that result from diseases involving blood vessels
-neurological symptoms result from ischemia

Front 3

What is ischemia?

Back 3

insufficiency of blood supply to tissue:
--irreversible damage of nervous tissue as early as 1-2 mins
--tissue dies after 4 mins without O2 at room temp

Front 4

Why is it important to study the blood supply to the brain?

Back 4

-CVA are often localized to certain regions of the brain
-knowing the location of blood flow disruption is useful for predicting the type and extent of neurosensory impairments

Front 5

True or false: Arterial blood flow remains generally constant in spite of changes in blood pressure.

Back 5

True

Front 6

What are 3 ways arterial blood pressure can be impeded by?

Back 6

-raised intracranial pressure from too much CSF
-increased blood viscosity perhaps due to diet factors
-narrowing of the vascular diameter (due to arterial sclerosis)

Front 7

What is the main artery from the heart?

Back 7

aorta

Front 8

What are the 2 main paired blood vessels that carry arterial blood supply from the heart to the brain?

Back 8

-common carotid arteries
-vertebral arteries

Front 9

What do the common carotid arteries bifurcate to form?

Back 9

the internal and external carotid arteries

Front 10

Where does the internal carotid artery arrive at?

Back 10

the base of the brain

Front 11

Where do the vertebral arteries ascend along AND where do they enter the cranium at?

Back 11

-ascend along the cervical vertebral column
-enters cranium through the foramen magnum

Front 12

Where do the vertebral arteries unite at AND what do they form?

Back 12

-unite at the base of the medulla
-form the basilar artery

Front 13

Where does the basilar artery travel along?

Back 13

travels along the midline on the ventral surface of the pons

Front 14

What does the internal carotid artery give rise to?

Back 14

-anterior cerebral artery
-middle cerebral artery

Front 15

What do the vertebrobasilar arteries supply?

Back 15

-entire brainstem
-cerebellum

Front 16

What do the vertebrobasilar arteries give rise to?

Back 16

give rise to the posterior cerebral artery

Front 17

Which arteries distribute blood to the cerebral hemispheres?

Back 17

-anterior cerebral artery
-middle cerebral artery
-posterior cerebral artery

Front 18

What structures do the anterior cerebral arteries feed into? (6)

Back 18

-medial surface of frontal and parietal lobes
-cortex and white matter of inferior frontal lobe
-anterior corpus callosum
-limbic structures
-head of caudate
-anterior limb of internal capsule

Front 19

What structures do the middle cerebral arteries feed into?

Back 19

-most of cortex and white matter (including frontal, parietal, temporal, occipital, and insular)
-smaller pentrating branches supply:
--basal ganglia
--posterior limb of the internal capsule (many descending tracts can be affected)

Front 20

Damage to which arteries affect Broca's area, Wernicke's area, and the primary motor strip?

Back 20

middle cerebral arteries affect these

Front 21

What structures do the posterior cerebral arteries feed into? (4)

Back 21

-inferior and medial occipital lobes (visual cortex)
-posterior corpus callosum
-thalamus
-parts of midbrain (red nucleus)

Front 22

Blockage of which artery would be most commonly associated with speech/language problems?

Back 22

middle cerebral artery

Front 23

What is one symptom that would be associated with disruption of blood flow to the anterior cerebral arteries?

Back 23

legs

Front 24

What symptoms would be associated with disruption of blood flow to the middle cerebral arteries?

Back 24

speech, auditory processing, apraxia

Front 25

What symptoms would be associated with disruption of blood flow to the posterior cerebral arteries?

Back 25

vision, sensory

Front 26

Interconnections between blood vessels prevent _________ when part of vascular supply is blocked.

Back 26

ischemia

Front 27

Describe the Circle of Willis.

Back 27

-describes interconnections between arteries providing blood flow to the brain (i.e. between:--the vertebral arteries and the internal capsule; --the anterior, middle, and posterior cerebral arteries)

-collateral circulation (redundant blood supply to the brain)

Front 28

What is the protective function of the Circle of Willis?

Back 28

if one side is affected, it can still function from the other side

Front 29

Large ________ collect blood from the cortical capillaries and lead it into a system of large _______.

Back 29

-veins
-sinuses

Front 30

Veins generally flow:

Back 30

the course of the major cerebral arteries

Front 31

What are sinuses formed from?

Back 31

formed from "tubes" in the dura mater

Front 32

What is the largest venous cavity?

Back 32

superior sagittal sinus (longitudinal fissure)

Front 33

List the venous drainage system of the brain.

Back 33

superior sagittal sinus and inferior sagittal sinus (from another area)--> straight sinus--> transverse sinus--> sigmoid sinus--> internal jugular vein

Front 34

What is the blood-brain barrier?

Back 34

tightly packed cells and capillaries

Front 35

What is the blood-brain barrier in the CNS?

Back 35

-no gaps exist between cells that line capillaries
-thus, exchange of substances requires active transport

Front 36

What is the blood-brain barrier in the body?

Back 36

-small gaps exists between capillaries allowing free exchange between blood and cells

Front 37

What did the blue dye experiment discover?

Back 37

the blood-brain barrier

Front 38

What function does the blood-brain barrier serve?

Back 38

-selective permeability that protects brain from harmful substances and infective agents (viruses and bacteria)

Front 39

What is the down-side to the blood-brain barrier?

Back 39

prevents most antibiotics from getting into the brain tissue to combat infection (encephalitis)

Front 40

What is passed thru the blood-brain barrier?

Back 40

-water
-CO2
-glucose
-anesthetics

Front 41

What is filtered by the blood-brain barrier?

Back 41

-most substances including proteins and antibiotics
-in some special regions that BBB is weak

Front 42

What is the area postrema?

Back 42

-area in medulla that controls vomiting that is relatively permeable permitting neurons in this region to detect toxic substance (weak spot in the BBB)

Front 43

True or false: CVAs are the 3rd major cause of death.

Back 43

True: more prevalent that death by accidents, but less than cancer and heart disease

Front 44

True or false: CVAs cannot cause subdermal hematomas.

Back 44

False

Front 45

What are the 3 types of CVAs?

Back 45

-thrombic
-hermorrhagic
-embolic

Front 46

Desribe a thrombic CVA.

Back 46

-blockage due to clot within artery
or
-stenosis (narrowing of artery)

Front 47

What is stenosis?

Back 47

narrowing of artery

Front 48

Describe hemorrhagic CVAs.

Back 48

-bursting of blood vessel in brain
-congenital (weakness in artery wall)
-advanced arteriosclerosis (build up of plaque which weakens walls)
-aneurysm - weak spot in artery wall

Front 49

Describe a embolic CVA.

Back 49

-blockage of artery from a traveling particle (cholesterol, blood clot, bubble of air or other gas, piece of tissue or tumor, clump of bacteria, bone marrow)

Front 50

What is necrosis AND what is it caused by?

Back 50

-death of tissue cells
-caused by ischemia

Front 51

What is infarction?

Back 51

-an area of tissue that undergoes necrosis as a result of ischemia

Front 52

What are 3 types of hemorrhages?

Back 52

-aneurysm
-AVM
-arterial hemorrhage

Front 53

Describe an aneurysm.

Back 53

-type of hemorrhage
-abnormal dilation of artery due to a weak spot or thinning of an arterial wall
-a sac-like protrusion from a blood vessel or the heart, resulting from a weakening of the vessel or heart muscle

Front 54

Describe an AVM.

Back 54

-arterial venous malformation
-child stroke
-type of hemorrhage
-congenitally deformed artery
-can occur at junction of artery

Front 55

Describe arterial hemorrhage.

Back 55

-type of hemorrhage
-artery blows open
-usually due to hypertension

Front 56

What deficits are associated with MCA lesions? (7)

Back 56

-contralateral hemiplegia
-cortical hypothesia
-heminopsia
-aphasia
-visual agnosia
-apraxia
-upper moter dysarthria

Front 57

What is contralateral hemiplegia?

Back 57

-weakness on one side of body
-face and arms usually more affected than legs
-usually focal, one hemisphere

Front 58

What is cortical hypothesia?

Back 58

numbness in same side as motor loss

Front 59

What is hemianopsia?

Back 59

loss of one half of visual field in each eye (e.g.; would affect left field of both eyes)

Front 60

What is visual agnosia?

Back 60

inability to assign meaning to what you see

Front 61

What is apraxia?

Back 61

motor planning problem

Front 62

True or false: Brain is part of UMN system.

Back 62

False: brain is part of LMN system; cranial nerves are part of UMN system

Front 63

What are deficits associated with ACA lesions? (4)

Back 63

-paralysis
-cognitive and emotional changes (dementia)
-apraxia of gait
-incompetence of bowl and bladder

Front 64

What are deficits associated with the PCA and Vertibrobasilar lesions? (6)

Back 64

-dyslexia
-memory impairments
-hemianopsia
-visual agnosia
-cortical blindness
-ataxic dysarthria (cerebellar blood supply)

Front 65

What is ataxic dysarthria?

Back 65

loss of coordination in speech (slurred, slow, variable pitch, variable movement, alternating tones)