Flashcards
NS 25 - CSF
Cards in this deck (28)
- 1Role of CSFprovides mechanical cushioning of brain
- 2Where is CSFsubarachnoid space + around brain and spinal cord
- 3Composition of CSFSodium (more than in plasma)
Potassium (less than in plasma)
Chloride (more than in plasma)
Glucose (c.70% of plasma levels)
Protein (v little)
pH (7.3 - blood = 7.4) - 4Characteristics of normal CSFclear, colourless
few WBCs
no RBCs
v. little protein
glucose - 5Total vol of CSF in subarachnoid space in ventricles140ml
117ml
23ml - 6why do blood and csf have different compositionstransporters promote entry of some substances while restricting entry of others from blood
- 7normal pressure of csf10mmHg
- 8flow of csflateral ventricles -> foramen of Monroe -> 3rd ventricle -> aqueduct of sylvius -> 4th ventricle -> foramen of magendie + foramina of luschka
- 9Formation of CSFIn choroid plexus by ependymal cells
- 10No. of choroid plexuses + structure4
2 cells thick - endothelial + ependyma
connected by tight junctions = seals off capillary wall - 11Role of Blood-CSF barrierrestricts free movement of substances from blood -> CSF
- 12Permeability to hydrophilic/lipophobiclow permeability
transport tightly regulated - depends on presence of specific transporters in walls of ependyma - 13Permeability to lipophilic/hydrophobicfree unrestricted movement
- 14Formation of Brain Interstitial Ffuid (ISF)Formed by plasma at cerebral capillary wall
Drains into CSF via subarachnoid space - 15Formation of blood brain barrierformed by walls of cerebral capillaries + transporters + astrocytes
- 16Structure of BBBSingle layer of flattened endothelial cells connected by tight junctions
Surrounded by basement membrane + astrocytes - 17Role of BBBRestricts movement of substances from blood -> brain ISF
- 18Neurooncology of BBBBBB absent in blood vessels associated with tumours = can use drugs that can't cross BBB to target these
- 19Pressure of ICP10mmHg
- 20Dangers of increased ICPcerebral vessels compressed = - cerebral blood flow = cerebral ischaemia
- 21Symptoms of + ICPInitial = headache, restlessness
Worsens = neural dysfunction (confusion, drowsiness) + Papilloedema
If continued = Cushing's reflex - 22Cushing's reflexoccurs when considerable loss of cerebral perfusion = brain is severely hypocapnic + hypoxic
- 23Hypercapniastimulates vasormotor sensor in medulla
= peripheral vasoconstriction
+ arterial BP
improve cerebral perfusion
+ firing in baroreceptors
+ activity of cardio-inhibitory centre
Reflex bradycardia - 24Causes of + ICPBrain haemorrhage
Brain tumour
Head injury/trauma - 25Contrecoup injurywhen brain is driven against skull following a severe blow to opposite side of skull
- 26Depressed skull fracturewhen skull is fractured and bone is driven into brain tissue
- 27Hydrocephalus+ CSF volume due to obstruction of CSF flow = enlargement of ventricles
= brain flattened against skull = brain damage - 28People affected by hydrocephalusInfants - stenosis/inflammation of aqueduct of sylvius
Adults - obstruction of Aqueduct of sylvius (obstruction of 4th ventricle outflow)
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- JC3 (Neuroscience ) Flashcards on NS 25 - CSF, created by Erica Lai on 30/11/2018.
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- Erica Lai
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