D2 - Arterial and venous blood supply of the brain and the spinal cord, the sinus system

Question 1

Blood supply of the brain

Arterial

Answer 1

• Ca, eq: blood supply to brain form paired a. carotis interna
• Fe, Ru: a. maxillaris → a. carotis cerebri (cerebral carotid artery)
• A. carotis interna / a. carotis cerebri penetrated the dura mater at the diaphragmatica sellae → cerebral arterial circle ventral to hypothalamus
• Branches:
  
  • A. cerebri rostralis
  • A. cerebri media
  • A. cerebri caudalis
  • A. cerebellaris rostralis
  • A. cerebellaris caudalis

Question 2

Blood supply of the brain

The venous drainage

Answer 2

• Complicated system of venous sinuses which are enclosed in dura mater
• Divided into dorsal and ventral system

Dorsal system:

• Sinus saggitalis dorsalis
• SInus rectus
• Sinus transversus
  
  • ​Sinus temporalis
  • Sinus sigmoideus

Ventral system:

• Sinus cavernosus
• Sinus basilaris
• Sinus petrosus ventralis
• Sinus intercavernosus
• Flow of blood into crania cavity:
  
  • Spreading of infections
  • Cooling the arterial blood supply to hypothalamus

Question 3

Blood supply of the spinal cord

Arterial

Answer 3

• The cervical spinal cord is vascularized by segmental arteries from a. vertebralis which branches from a. subclavia
• The rest receives blood from:
  
  • A. cervicalis
  • A. intercostalis
  • A. lumbaris
• They enters the vertebral canal through for. intervertebrale
• Three arteries runs in length of the spinal cord:
  
  • A. spinalis ventralis
    
    • ​Unpaired
    • Follows surface of fissura mediana
    • Supports grey matter and white substance
  • A. spinalis dorsalis
    
    • ​Paired
    • Runs close to dorsal root
• All these three arteires receive reinforement by brances of regional arteries:
  
  • A. vertebralis (neck)
  • A. intercostales thoracica
  • A. intercostales lumbales

Question 4

Blood supply of the spinal cord

Venous

Answer 4

• Venous plexus: runs all length of vertebral column and drian blood with canalis vertebralis
• Plexus vertebralis internus ventralis (floor of canalis vertebralis)
• Plexus verebralis externus dors./ventr. (dors./ventr. aspect of columna vertebralis)
• V. intervertebralis (passes through for. intervertebrale)
• Vv. spinalis (longitudinal veins alont medulla spinalis)
• Vv. basivertebrae (perforate corpus vertebrae)
• The venous plexus gives rise to segmental veins that leave the canal through the forr. intervertebralis to join the principal venous channels of the neck and trunk:
  
  • V. vertebralis
  • V. cava cranialis
  • V. azygous
  • V. cava caudalis
• The major part of the plexus consists of paired channels within the epidural space ventral to the cord