Neuroanatomy Flashcards
What is CSF
Where is this produced
-It is an Ultrafiltrate of blood
Produced by the epithelial cells of the choroid plexus
found in the walls of the lateral , third and 4th
ventricles
How much CSF is present in mls
150 ml
* 125 ml is intracranial
* The ventricles contain about 25
ml
* 100 ml is located in the cranial
subarachnoid space
What is the rate of secretion of CSF
Secreted at a rate of 0.35–0.40
ml per minute
What is the function of CSF
Lubrication
* Shock absorber
* Transporter
* Nutrients
* Waste products
* Hormones
Where is the CSF Secreted
Choroid plexus (lateral, third and fourth ventricles), interstitial space and dura of the nerve root sleeves
Discuss the Circulation of CSF
Lateral ventricle → Through inter ventricular foramina -Munro–third ventricle →cerebral aqueduct of sylvius – fourth ventricle → central canal of spinal cord → subarachnoid space
Absorption of CSF
Arachnoid granulations, choroid plexuses and glymphatics
Functions of CSF
Removal of waste, cushioning of brain and intracranial neurovascular structures, neutral buoyancy, electrolytic homeostasis
What is the most significant disorder of the CSF flow
The Hydrocephalus is caused by
excessive amounts of CSF, either caused by increased production (hypersecretory hydrocephalus), an obstruction of its flow (non-communicating or obstructive hydrocephalus), or by
impaired absorption through the arachnoid villi (malabsorptive hydrocephalus). in the cranium leading to a degeneration of brain tissue.
What is the effect of hydrocephalus
Hydrocephalus is followed by an abnormal enlargement of the head in children due to an abnormal increase in the amount of CSF. This creates increased pressure within the cranium leading to a degeneration of brain tissue.
How can you classify Hydrocephalus
Hydrocephalus is classified as obstructive (non-communicating) when there is an obstruction to its flow from the ventricular system to the subarachnoid space; or as communicating when such obstruction is not present. Obstructions are most likely to occur at narrow passages such as the interventricular foramen, the cerebral aqueduct, the median aperture, and lateral apertures of the fourth ventricle
What is Malabsorptive hydrocephalus?
Malabsorptive hydrocephalus often arises in the aftermath of subarachnoid hemorrhage and meningitis, both of which can produce occlusive adhesions of the arachnoid granulations. It can also result from traumatic brain injury and intraventricular hemorrhage.
Hydrocephalus can also be active if the pressure inside the ventricular system is continuously elevated. Active hydrocephalus is not the same as normal pressure hydrocephalus, in which CSF pressure is only intermittently elevated.
What is the commonest cause of hydrocephalus
Interruption of the normal CSF absorption through arachnoidal granulations
Occurs after sub arachnoid haemorrhage -when blood enters sub arachnoid space and interferes with absorption
