Physiology Flashcards
Where is CSF produced?
By the secretory epithelium of the choroid plexus
What does CSF supply?
Water, amino acids and ions
How much volume of CSF is there at any one time?
150mls volume, replaced 3/4x daily
What are the 3 major functions of CSF
Mechanical protection- shock absorbing
Homeostatic function- pH of CSF affects pulmonary ventilation
When does the nervous system begin to develop?
At 3 weeks
Consists of a tube (neural canal)
What does the neural canal give rise to?
The brains ventricles and the spinal cord central canal
How is the choroid fissure formed
Developing arteries invaginate the roof of the ventricle to form the choroid fissure
What is involved in the production of CSF
The transport of ions across the epithelium from blood to CSF
What allows secretion to occur?
Due to the polarised distribution of specific ion transporters in the apical or basolateral membrane of epithelial cells
What connects the lateral ventricles to the third ventricle?
Intraventricular foramina of monroe
What connects the third ventricle to the forth?
Cerebral aqueduct of sylvius
How does CSF enter the subarachnoid space?
Through 3 openings in the roof of the 4th ventricle
Where is the site of the BBB
Endothelial cells in brain capillaries
What is the BBB
Consists of the capillary epithelium, it’s basal membrane and peri vascular astrocytes
What are some tumours related to CSF
Colloid cyst- found at interventricular foramen
Ependymomas- arises from ependymal cells lining the ventricles
