Week 7: Internal structures, cranial nerves, and blood supply to the brain

Question 1

Describe the path of the cerebrospinal fluid.

Answer 1

• Produced in the choroid plexuses.
  
  • Network of blood vessels in all four ventricles of the brain.
  • Found mainly in the left and right ventricles (ventricles I and II) (lateral ventricles).
• CSF flows from the lateral ventricles to the third ventricle.
  
  • Passes through the narrow interventricular foramina.
    
    • Also known as the Foramina of Monro.
• Flows through the third ventricle to the narrow cerebral aqueduct, to enter the fourth ventricle.
  
  • Fourth ventricle shaped like a diamond.
• Leaves this ventricle into the subarachnoid space through:
  
  • Central canal.
  • Lateral two apertures.
  • Median aperture.
• Resorbed through the arachnoid villi into the superior sagittal sinus.
  
  • SSS = inverted triangle.

Question 2

Label the following diagram of the Circle of Willis.

Answer 2