Neuropathology Flashcards
name three types of glial cells and their function
1) astrocytes - metabolic control (hug around blood vessels and contact neurons) 2) oligodendrocytes - structure and clasp around axons In the CNS and myelinated them 3) ependyma - line fluid compartments (equiv of epithelium) 4) microglia - monocyte lineage population
what are the components of SCALP?
Skin and Connective tissue Apneurosis Loose connective tissue Periosteum
which layer of the meninges covers the brain is continues into the spinal cord?
dura mater
what is the normal volume of CSF in the brain and how much is made per 24 hours?
- normal volume is 150ml 450ml is made per 24 hours
what connects the lateral ventricles and third ventricle?
inter ventricular foramen
what connects the 3rd to the 4th ventricle?
the cerebral aqueduct
where does the fourth ventricle connect to in the spinal column?
the central canal
how is CSF produced by the choroid plexus?
through ultrafiltration of blood
what are arachnoid granulations and what do they do?
arachnid granulations are outpocketings of the arachnoid into the dura - resorption of fluid back into the venous system (superior saggital sinus)
what condition arises when CSF circulation goes wrong?
hydrocephalus
what is the mechanism of hydrocephalus? (4)
- impaired resorption at arachnoid granulations - continous production by the choroid plexus - no drainage into venous system - therefore increase in ICP
what structural abnormality may cause hydrocephalus
shrinking of brain tissue eg in dementia
what is i) communicating ii) non communicating hydrocephalus?
I) communicating = whole system affected ii) non communicating = isolated problem
what causes a raised ICP? give three examples of this
raised ICP can be caused by space occupying lesions - neoplasm, haemorrhage and abscess
what is the main consequence of raised ICP?
herniation
what type of herniation is caused by i) brain pulled under faux cerebri ii) brain pulled through tentorium cerebelli iii) brain pulled through foramen magnum
i) subfalcine ii) transtentorial/central iii) tonsillar/cerebellar
what type of herniations are a,b,c?
a) through falx cerebri
b) through tentorium cerebelli
c) through foramen magnum
give three examples of parenchymal injuries
1) contusion (bruising)
2) laceration (penetration or tearing)
3) diffuse axonal injury
what causes a diffuse axonal injury? is this structural or functional?
caused by impact forces that makes the whole axonal network stop working
- functional injury
what happens when:
i) a moving head hits a stationary object
ii) stationary head hits a moving object
i) coup and contrecoup
ii) just coup