l12 Flashcards
what is the ventricular system
Series of CSF filled interconnected spaces
What is the ventricular system continuous with
the subarachnoid space and central canal
Lateral ventricles anatomy
Body anterior posterior and inferior horn
what seperates the lateral ventricles
Septum Pellucidum
What sits on the roof of the lateral ventricles
The corpus callosum
What sits in the lateral wall of the ventricles
The caudate nucleus
What sits in the floor of the ventricles inferior horn
The hippocampus
What does the lateral ventricles communicate though to the third ventricle
The interventricular foramen
Describe the location and some features of the third ventricle
Between the thalami and fornix forms roof
Look at slide 12
Look at it
what does the fourth ventricle communicate to the third ventricle through
Cerebral aqueduct
what is the 4th ventricle surrounded by
Hindbrain
What is the cerebellum posterior, the pons and medulla anterior and the cerebellar peduncles lateral to
The 4th ventricle
What is the 4th ventricle continuous with
Central canal and subarachnoid space
look at slide 15
Look at it
what does the 4th ventricle communicate through to the cisterna magna
2 foramen of Luschka
1 foramen of magendie
What is the CSF produced by
The choroid plexus
Function of the choroid plexus
It filters blood from branches of internal carotid and basilar arteries
what type of epithelium surround he choroid plexus?
Cuboidal epithelium
What is the process of CSF production
1) blood filtered through fenestrated capillaries
2) Components transported through cuboidal epithelium into ventricles
Tight junctions between epithelial cells…
Prevent macromolecules from entering CSF
Permeable to water and CO2
Give 4 features of cuboidal epithelium
Specialised ependyma:
villi-increase SA
Active transport of CSF components
Bidirectional-uptake of metabolites into circ system
What is the conc of proteins in CSF compared to plasma
0.18g/l in CSF
75g/l in plasma
ideal for functioning of neurons
CSF Circ part 1
:Lateral ventricles-3rd ventricle-4th ventricle-cisterna magna -subarachnoid space
CSF circ part 2
Up ventral spinal subarachnoid space or bypass via cerebral hemispheres (cerebellum)- over cerebral hemispheres-(via arachnoid granulations and sup sagittal sinus)- down dorsal spinal subarach space
Subarachnoid space describe and function
Lies between pia and arachnoid
Functionally important -CSF in contact with brain parenchyma- transfer of micronutrients into brain-removal of metabolites
what are arachnoid granulations
Herniations of arachnoid membrane through dura mater into venous sinuses
What are the main venous sinuses
Superior sagittal and transverse sinuses
Arachnoid granulations perforate
The dura
Absorption of CF: pressures
150mm water in subarachnoid space
80mm in venous sinuses
If venous pressure exceeds CSF pressure
Tips of villi close off and prevents reflux of blood into subarachnoid space
total csf volume range and total produced in one day- reason for difference
90-140ml
but 500ml produced by day
Continuously moving
Excess absorbed by arachnoid granulations
4 main functions of CSF
Hydraulic buffer to cushion brain against trauma
vehicle for removal of metabolites from CNS
Stable ionic environment for neuronal function
Transport of neurotransmitters and chemicals
Colour of CSF in disease
Xanthocromia-yellow-due to subarachnoid haemorrhage
CLOUDY
During multiple sclerosis-protein content
Bacterial meningitis- Leukocytes
CSF sampling is taken how and where
By lumbar puncture at lumbar cistern
What is hydrocephalus
Dilation of the brain ventricles
Due to blocked CSF circulation, impaired absorption or over secretion
Causing increased intracranial pressure
Affecting neurological function
Describe non-communicating hydrocephalus
Blockage within the ventricular system due to tumour -cyst
CSF doesn’t circulate over the brain urface
Cure for non-commun hydrocephalus
Surgery -insert a shunt to reduce intracranial pressure
What is the dandy walker syndrome
non-communicating
Congenital malformation of the cerebellum
obstruction within the foramina of 4th ventricle
in infancy child’s head becomes enlarged
What is communicating hydrocephalus
Obstruction in the arachnoid villi
Movement of CSF into venous sinuses is impeded
Impaired absorption following subarachnoid haemorrhage trauma or bacterial meningitis-Acquired
