circulation to the brain and spinal cord: CSF and Vascular Systems

Question 1

what are the two fluid systems?

Answer 1

cerebrospinal fluid (CSF)

vascular

Question 2

what are examples of CSF? (3)

Answer 2

ventricles
meninges
CSF

Question 3

what are examples of vascular?

Answer 3

arterial supply
veins and venous sinuses
regulatory mechanisms of blood supply

Question 4

Where is CSF formed? and where does it flow?

Answer 4

ventricles (choroid plexus)

between ventricles and into subarachnoid space then eventually is absorbed into venous system

Question 5

what is the CSF responsible for?

Answer 5

supplying nutrients and removing waste products

Question 6

2 C shaped lateral ventricles borders:

lateral – (?)
below body – (?)
above body – (?)

Answer 6

lateral –> caudate nucleus with tail of caudate superior to inferior horn
below body –> thalamus
above body –> corpus callosum

Question 7

what do the 2 C shaped lateral ventricles connect to?

Answer 7

connect to each other and to the 3rd ventricle by inter-ventricular foramina (foramina of Monro)

Question 8

what is the third ventricle surrounded by?

Answer 8

thalamus and hypothalamus

Question 9

what connects the 3rd and 4th ventricles?

Answer 9

cerebral aqueduct thru midbrain

Question 10

where is the 4th ventricle?

Answer 10

posterior to pons/medulla and anterior to cerebellum

Question 11

what does the 4th ventricle connect to?

Answer 11

the central canal of the spinal cord

Question 12

where does the 4th ventricle drain?

Answer 12

subarachnoid space thru 2 lateral foramina (foramina of Luschka) and midline foreman of Magendie

Question 13

what secretes CSF?

Answer 13

choroid plexuses

Question 14

what are epidural hematomas most often a result of?

Answer 14

fracture of the parietal or temporal bones tearing middle meningeal artery

Question 15

what are three key characteristics of epidural hematoma?

Answer 15

quick accumulation of blood

period of lucidity, then quick deterioration

characteristic lens shaped accumulation of blood

Question 16

what is a subdural hematoma most often a result of?

Answer 16

venous bleed

Question 17

what is one key characteristic of a subdural hematoma?

Answer 17

slow progressive deterioration (days, months)

Question 18

congenital or acquired hydrocephalus:

what is a characteristic of infants with non-fused skulls?

Answer 18

enlarged heads and other symtpoms/signs

Question 19

congenital or acquired hydrocephalus:

what is a characteristic of children/adults with fused skulls?

Answer 19

excessive pressure especially of white matter and will exhibit a TRIAD of symptoms

Question 20

what is the triad of symptoms for congenital or acquired hydrocephalus?

Answer 20

worsening gait, incontinence, HA or cognitive deficits

Question 21

what is communicating hydrocephalus?

Answer 21

ventricular system intact with blockage caudal to 4th ventricle

Question 22

what is noncommunicating/obstructive hydrocephalus?

Answer 22

blockage within ventricular system (usually cerebral aqueduct)

Question 23

what are the four types of hydrocephalus?

Answer 23

congenital or acquired

communicating

noncommunicating/obstructive

requires ventriculoperitoneal stunt

Question 24

what is meningitis?

Answer 24

inflammation of the meninges

Question 25

when does pain increase for meningitis?

Answer 25

with upright position, with head movement, and sneezing or coughing

Question 26

how many arteries are supplying anterior SC?

Answer 26

one artery

Question 27

how many arteries are supplying for posterior SC?

Answer 27

two arteries

Question 28

how much of the spinal cord does the anterior spinal artery supply?

Answer 28

1/2 of SC

Question 29

what is arteriovenous malformation?

Answer 29

arteries connect to abnormal vessels rather than capillaries to veins

Question 30

true or false: arteriovenous malformations are congenital

Answer 30

true

Question 31

what are three characteristics of arteriovenous malformation?

Answer 31

can be asymptomatic till ruptures symptoms can include local pain can be found anywhere in body

Question 32

what are aneurysms?

Answer 32

thin walled out-pouching from artery or vein

Question 33

true or false: aneurysms can be congenital and worsen with age (hypertension)

Answer 33

TRUE

Question 34

what is one main characteristic of aneurysms?

Answer 34

can be asymptomatic until it leaks or ruptures can be found anywhere in circulatory system

Question 35

what is the blood brain barrier?

Answer 35

a specialized barrier between capillary endothelium of CNS and extracellular space

Question 36

what is a characteristic of permeability for the blood brain barrier? and why is it important?

Answer 36

permeability is less than regular capillaries so large molecules can't enter it is important because it is beneficial to prevent lots of pathogens from entering CNS and prevents certain drugs and protein antibodies from entering

Question 37

where is the blood brain barrier absent in?

Answer 37

areas that sample the blood or secrete into the blood such as... parts of hypothalamus and other areas close to 3rd/4th ventricles AND special ependymal cells separate leaky regions from barrier-ed ones

Question 38

what is more vulnerable to O2 loss than life centers of brainstem?

Answer 38

cortex

Question 39

when does dilation of the cerebral arteries occur?

Answer 39

if BP, O2, or pH levels are low OR CO2 or lactic acid is high

Question 40

when does constriction of the cerebral arteries occur?

Answer 40

if BP, O2, or pH levels are high or if CO2 or lactic acid is high

Question 41

what is cerebral edema?

Answer 41

excessive fluid in brain tissue

Question 42

what are common causes of cerebral edema?

Answer 42

TBI, including concussion heart attack high altitude cerebral edema

Question 43

cerebral edema is progressive because fluid pressure causes ischemia which leads to what?

Answer 43

arterioles to dilate and increases capillary pressure and permeability and more edema

Question 44

what is intracranial pressure?

Answer 44

pressure within the skull, measured by monitor in lateral ventricle

Question 45

what is the normal range of intracranial pressure?

Answer 45

5-15 mm HG

Question 46

what does an intracranial pressure above 15 mean?

Answer 46

abnormality

Question 47

what does an intracranial pressure above 20 or greater mean?

Answer 47

pathologic and contraindication for PT

Question 48

what can an excessive ICP cause?

Answer 48

compress brain tissue move brain structures cause hydrocephalus cause brain herniation disrupt blood supply

Question 49

brain herniation: pressure against the falx cerebri (cingulate) can likely cause what? (homunculus)

Answer 49

it can lead to compression in the region of the homunculus primarily controlling the lower limb particularly the foot and leg

Question 50

brain herniation: pressure against the uncal on the midbrain can cause what?

Answer 50

CN3 dysfunction and loss of consciousness (reticular activating system)

Question 51

brain herniation: pressure against the central aspect of the brain against the diencephalon moving it, midbrain and pons down causes what?

Answer 51

stretches basilar artery with brainstem ischemia/edema B paralysis and impaired consciousness and oculomotor function

Question 52

pressure on the cerebellar tonsils putting downward on brainstem does what?

Answer 52

impairs consciousness and and can lead to respiratory and cardiovascular failure

Question 53

what is a transient ischemic attack?

Answer 53

brief localized loss of brain function resolves within 24 hours medical emergency due to high likelihood of bigger stroke to happen alter

Question 54

what is a stroke?

Answer 54

CVA lasting longer than 1 day "brain attack"

Question 55

what are two types of infarctions?

Answer 55

embolus and thrombus

Question 56

what is an embolus? and what can it cause?

Answer 56

clot from somewhere else sudden quick loss of function

Question 57

what is a thrombus? and what can it cause?

Answer 57

narrowing and/or clot in area involved gradual worsening of function (mins to days)

Question 58

what is the main difference between embolus and thrombus?

Answer 58

embolus is SUDDEN and QUICK loss of function thrombus is GRADUAL worsening of function

Question 59

80% of all strokes are what type?

Answer 59

infarctions

Question 60

most strokes affect what blood vessels?

Answer 60

middle cerebral artery

Question 61

what are small deep circulation infarcts called?

Answer 61

lacunar infarcts

Question 62

what is a hemorrhage?

Answer 62

rupture of vessel

Question 63

what can a hemorrhage cause?

Answer 63

sudden loss of function, severe HA (headache) to loss of consciousness

Question 64

what is the damage from a hemorrhage due to?

Answer 64

downstream loss of blood to brain areas pressure of extracellular blood accumulating blood where not supposed to be is irritant to brain tissue

Question 65

stroke signs/symptoms by arterial location: what injuries are vertebral arteries prone to?

Answer 65

shear force injuries, especially abrupt cervical rotation or hyperextension with chief symptom of pain

Question 66

the vertebral arteries supply the cerebellum and brainstem... so what happens when there is a disruption of blood flow (vertebrobasilar ischemia) in the vertebrobasilar system?

Answer 66

gait/limb ataxia/incoordination and weakness, oculomotor and oropharyngeal impairments, numbness, dizziness, HA, vomiting

Question 67

what does complete blockage of the basilar artery cause?

Answer 67

death due to ischemia of brainstem with vital functions

Question 68

what can partial blockage of the basilar artery cause?

Answer 68

tetraplegia, numbness, loss of consciousness, cranial nerve damage

Question 69

a partial blockage of what artery can cause locked in syndrome?

Answer 69

basilar artery

Question 70

a stroke in the anterior cerebral artery can cause hemiparesis/hemisensory loss to what body parts more than others?

Answer 70

the contralateral lower limb more than the upper limb or face

Question 71

what can a stroke in the anterior cerebral artery cause?

Answer 71

hemiparesis/hemisensory loss to contralateral lower limb and personality changes

Question 72

what is the mnemonic for MCA strokes to know what part of the body is affected?

Answer 72

MCA Mostly Cheek and Arm

Question 73

what body parts result to hemiparesis/hemisensory loss to contralateral side during a stroke of the MCA?

Answer 73

the upper limbs and face

Question 74

if there is a stroke on the left side of the brain in a MCA stroke, what is affected?

Answer 74

language

Question 75

if there is a stroke on the right side of the brain in a MCA stroke, what is affected?

Answer 75

spatial relationships neglect nonverbal communication

Question 76

what parts of the brain does the posterior cerebral artery supply?

Answer 76

midbrain, diencephalon, hippocampus, and thalamus

Question 77

if the PCA stroke affects the hippocampus, what is affected?

Answer 77

declarative memory

Question 78

if the PCA stroke affects the thalamus, what is affected?

Answer 78

pain, contralateral hemiparesis/hemisensory loss

Question 79

if there is a PCA stroke, what is affected?

Answer 79

blood supply to the midbrain, diencephalon, hippocampus, thalamus, eye movement, and cortical blindness

Question 80

what are watershed areas in terms of a stroke?

Answer 80

regions of the brain that lie at junctions between two major cerebral arteries

Question 81

what is arterial anastromoses?

Answer 81

occurs when two or more arteries joint to form a network, providing collateral circulation to tissues in case on artery becomes blocked

Question 82

are watershed areas vulnerable to ischemia?

Answer 82

yes