L12-Ventricular System Flashcards
Where is the septum pellucidum? What structures lies above?
Separates lateral ventricles
Contains both white and grey matter
above is corpus callosum
What forms the basal ganglia?
Lentiform nucleus and caudate nucleus
What is the foramen of Monro
Aka interventricular foramen
Communication between the lateral ventricles and third ventricles
Where is the Third ventricle
Slit like cleft between thalami
What is the cerebral aqueduct
Communication between third and fourth ventricle
Surrounded by mesencephalon (midbrain)
How does the fourth ventricle communicate
2 foramen of luschka
1 foramen of magendie
What is the choroid plexus?
Filtration system that produces CSF
ABOUT 60% produced here
Describe CSF production
Blood is filtered through fenestrated capillaries
Transport of components across epithelium cells into ventricles
What is the importance of the tight junctions between the epithelial cells?
Forms blood-CSF barrier
Prevents macromolecules from entering CSF
What is the functional importance of the subarachnoid space?
- transfer of micronutrients into brain
- removal of metabolites
What must occur before CSF can be absorbed?
CSF pressure must be higher than pressure in venous sinuses
What are the main functions of CSF?
- Hydraulic buffer to cushion brain against trauma
- Vehicle for removal of metabolites from CNS
- Stable ionic environment for neuronal function
(communicates with brain interstitial fluid via pia) - Transport of neurotransmitters and chemicals
What can yellow CSF suggest
Subarachnoid haemorrhage due to bilirubin
What can cloudy CSF suggest?
Multiple sclerosis
Bacterial meningitis
What is hydrocephalus
Water in the ventricles
Due to impaired CSF circulation
What is dandy-walker syndrome
Congenital form of non-communicating hydrocephalus
Cerebellum doesn’t grow
All ventricles are dilated
What is non-communicating hydrocephalus?
-how would you treat
Blockage within the ventricular system
-Insert shunt to reduce intracranial pressure
What is communicating hydrocephalus?
How may it occur?
Obstruction in the arachnoid villi
- Movement of CSF into venous sinuses is impeded
- E.g. Impaired absorption following subarachnoid haemorrhage, trauma or bacterial meningitis
What is the name of the layer that lines the ventricles?
Ependymal layer
Where do the ventricles and canals arise (embryology)? From which layer does this arise?
lumen of neural tube
from neuroectoderm
Telencephalon
cerebral hemispheres
- cerebral hemispheres
- lateral ventricles
