Organ
Choroid plexus
Ventricular secretory tissue forming the blood–CSF barrier
High-yield
A common adult teaching estimate is about 150 mL of CSF present and roughly 500 mL produced daily, equivalent to around three to four turnovers. Actual volumes and rates vary.
Overview
Choroid plexus consists of vascular connective tissue covered by specialized epithelial cells. It occurs in both lateral ventricles and in the third and fourth ventricles. Active transport across its epithelium helps produce CSF and regulate its composition.
Reference facts
- Location
- Along the choroidal fissures of the lateral ventricles, including body, atrium and temporal horn, and in the roofs of the third and fourth ventricles
- Parts
- Fenestrated capillaries and connective tissue covered by choroid epithelial cells joined by tight junctions
- Blood supply
- Anterior and posterior choroidal arteries supply supratentorial plexus; PICA and AICA contribute to fourth-ventricular plexus, with anatomical variation
- Function
- Major site of CSF secretion and the blood–CSF barrier; other brain-fluid interfaces also contribute to fluid exchange
Clinical correlation
CSF normally has much less protein than plasma, lower glucose and potassium, and higher chloride. Selective transport and epithelial tight junctions help maintain this different fluid environment.
Frequently asked questions
Where is the choroid plexus located?
Along the choroidal fissures of the lateral ventricles, including body, atrium and temporal horn, and in the roofs of the third and fourth ventricles.
What does the choroid plexus do?
Major site of CSF secretion and the blood–CSF barrier; other brain-fluid interfaces also contribute to fluid exchange.
What are the parts of the choroid plexus?
The parts of the choroid plexus are the fenestrated capillaries and connective tissue covered by choroid epithelial cells joined by tight junctions.
What is the blood supply of the choroid plexus?
Anterior and posterior choroidal arteries supply supratentorial plexus; PICA and AICA contribute to fourth-ventricular plexus, with anatomical variation.