Blood-Brain Barrier And Cerebral Perfusion Practice Test

Which of the following best describes the sequence of events in CSF formation?

Water movement precedes ion transport Ion transport creates an osmotic gradient, followed by water movement through Aquaporin-1 CSF forms purely by diffusion of water CSF forms by vesicular secretion from neurons

Correct Answer:

Ion transport creates an osmotic gradient, followed by water movement through Aquaporin-1

Explanation:

CSF formation begins with active ion transport by the choroid plexus epithelium, which creates an osmotic gradient across the cell layer. This osmotic gradient draws water into the ventricular space, and water moves readily through Aquaporin-1 channels on the epithelial cells into the CSF. So the sequence is ions moved to generate the osmotic pull, followed by water movement via AQP1. The other ideas don’t fit: water moving first would not establish the driving force, diffusion of water is too slow to account for CSF production, and CSF isn’t produced by vesicular secretion from neurons.

Access more questions from this quiz

Continue to Blood-Brain Barrier and Cerebral Perfusion Practice Test for more practice questions and the full quiz experience.

Access More Questions