Welliver Paper-Josh Flashcards
The composition of the Cranial vault contains what 3 components which together determine ICP? for extra credit what % soed each make up?
- Brain tissue (80%)
- Blood (12%)
- CSF (8%)
Brain is 80%
how much does it weigh in grams? and lbs? and % of tbw?
- 1300g
- 3 lbs
- 2%
Blood is 12%
it receives how much of CO? how much total flow mL/min
- 15-20% CO
- 750mL/min
CSF 8%
how many mL in cranium and spinal cord total? how many mL in cranium ar any given time?
- 150mL
- 75mL
Normal ICP is what?
<= 10 mmHg
CSF production is by the _____ in the ____ _____ and makes approx ____ mL/day?
- Choroid plexuses
- Lateral ventricles
- 400mL
The ______ allows bilateral communication of internal carotid and vertebral artery blood flow?
Circle of Willis
Tumor locations are generally described as ______ or ______
- supratentorial
- Infratentorial
what is the CSF flow through the Brain?
- Choroid plexus (in lateral ventricles)
- Foromen of Monro
- 3rd ventricle
- Aqueduct of Sylvius
- Fourth Ventricle
- Foramen of Magendi & Luschka
- Cistern Magna
- Subarachnoid space and Spinal Column
- absorbed via Vill of SA space
CBF:
what is the avg CBF
(mL/g/min)
50mL/100g/min
CBF:
what is the total CBF (mL/min)
750mL/min
CBF:
what is the range of CBF?
(mL/g/min)
10-300 mL/100g/min
CBF:
the gray matter (neuronal bodies) receives how much of the CBF?
80mL/g/min
CBF:
thus the white matter (axons) receive how much CBF?
20mL/g/min
CBF:
alteration in CBF may be detrimental by drawing blood away from _____ areas or beneficial by providing more blood, and hence O2 to _____ areas
- Ischemic
- Ischemic
CBF:
CBF occurs throough what?
Circle of Willis
CBF:
list 3 factors that can affect CBF?
- Luxury perfusion
- Steal Phenomenon
- Inverse steal or Robin hood phenomenon
Factors that Affect CBF:
which factor is when perfusion excess of metabolic needs?
Luxury Perfusion
(you have too much your living the dream.. I’m rick james bitch)
Factors that Affect CBF:
Luxury Perfusion may be beneficial in healthy brains but may cause ______ in brains which have ischemic areas
“Steal Phenomenon”
Factors that Affect CBF:
w/ luxury perfusion what is 2 examples in which it may occur?
- Tumor Metabolites that cause vasodiltion in surrounding tissues
- VAAs decrease CMRO2 and Increase CBF
Factors that Affect CBF:
is Steal phenomenon detrimental or beneficial
Detrimental (bad bad bad)
Factors that Affect CBF:
what phenomenon is blood is stolen from ischemic areas of the brain by causing vasodilation in healthy areas of the brain.
Steal Phenomenon
Factors that Affect CBF:
w/ Steal Phenomenon what are 2 things that can cause it
- Increased PaCO2
- VAAs
Factors that Affect CBF:
why is Steal Phenomenon so detrimental?
Ischemic Brain tissue, which has already maximally dilated vessels due to released vasodilator subnstances, loses luxury perfusion due to global shunting of blood flow
Factors that Affect CBF:
what is the inverse steal or Robin hood phenomenon
- Decreased pCO2 constrictes normal velles but not necessarily the ischemic areas d/t vasomotor paralysis. this is one rational for hyperventilating pt’s w. intracranial tumors associatd w/ increased ICP especially when administering VAAs whch cause Vasodilation
Circle of Willis:
what are the 5 (8 total) arteries of circle of willis?
- Anterior Cerebral Artery (2)
- Anterior Communicating Artery (1)
- Internal Carotid Atery (2)
- Posterior communicating Artery (2)
- Posterior cerebral artery (1)
Circle of Willis:
what 2 (3 total) arteries are connected to the circle of willis but not actually part of the circle of willis?
- Basilar artery (1)
- Vertebral artery (2)
Determinants of CBF:
PaCO2 has a ____ relationship
Linear relationship
Determinants of CBF:
PaCO2- a 1mmHg increase = what to CBF
- 1-2 mL/100g/min increase in CBF
Determinants of CBF:
PaO2- there is a profound increase in CBF anly at a PaO2 ______mmHg?
< 50 mmHg