C8 - Fluid environment of the brain and spinal cord, circulation of the cerebrospinal fluid

Question 1

Give the locations of the fluid enviornment of the brain

Answer 1

• Cavum epidurale (​Between dura mater and spinal cord)
• Cavum subdurale (​Between dura mater and arachnoidea)
• Cavum subarachnoidale (Between arachnoid and pia matter, filled with CSF)
  
  • Cisterna subarachnoideales (enlargements of the subarachnoid space)
    
    • ​Cisterna cerebromedullaris (between cerebellum and medulla)
    • Cisterna magna (between cerebellum and medulla oblongata, cerebrospinal fluid in the 4^th ventricle drains into the cisterna magna)
    • Cisterna lumbalis (between conus medullaris of spinal cord (L2) and inferior end of subarachnoid space and dura mater)

Question 2

Ventricular system

Answer 2

• The ventricles of the brain are continuation of the central canal of the spinal cord
• Filled with CSF
• Two lateral ventricles
  
  • Communicates with 3^rd ventricle
  • One in each hemisphere of the telencephalon
• 3^rd ventricle
  
  • Surrounds interthalamic adhesion of diencephalon
• 4^th ventricle
  
  • ​Rhombocephalon
• The lateral ventricle and 3^rd ventricle are joined by the for. interventriculare
• 3^rd ventricle and 4^th ventricle are joined by the mesencephalic aqueduct

Question 3

What is cerebrospinal fluid formed by?

Answer 3

Blood plasma of choroid plexus of the brain

Question 4

Location of choroid plexus

Answer 4

• 1 in each lateral ventricle
• 2 in each:
  
  • 3^rd ventricle
  • 4^th ventricle

Stemmer dette??

Question 5

Give the circulation of the CSF

Answer 5

1. Steps:
   
   1. Circulates through the ventricular system
   2. Escapes from the interior of the brain through the apertura lateralis of 4^th ventricle
      
      1. ​Car: Apertura mediana (Ø apertura lateralis)
   3. Returns to blood → transferred to the systemic circulation via venous sinuses
   4. A smaller part of the fluid circulates around the spinal and cranial nerves at their origin

• Within:
  
  • Ventricular system
  • Central canal
  • Subarachnoid space​

Question 6

Where does the CSF enter the subarachnoid space

Answer 6

From the 4^th ventricle

Question 7

Give the function of the CSF

Answer 7

• Chemical buffer
• Transport of nutrients and waste
• Acts as a lymphatic system

Question 8

Which vessels forms the choroid plexus of the 3^rd ventricle

Answer 8

Branches of a. cerebellaris caudalis