Blood Supply to Brain

Question 1

Protective coverings of brain

Answer 1

cranium
meninges: dura mater, pia mater and nachnoid
20% of blood supply goes to brain, uses 20% of glucose and O2

Question 2

Arterial supply to brain

Answer 2

• Pair of carotid arteries supply anterior brain
• pair of vertebral arteries supply posterior
  Left and right vertebral arteries some together to single basilar artery. internal Carotid arteries join single basilar artery in a ring at base of brain called circle of willis.

Question 3

Circle of Willis

Answer 3

Safety mechanism so that if one of arteries get blocked the circle will still provide brain with blood. six sided polygon of arteries which is formed around interpednucular fossa. contributes most of blood top brain

Question 4

Venous Return

Answer 4

veins of brain drain into intracranial dura venous sinus which then eventually opens into internal jugular veins of neck,
Veins of brain doesn’t follow same path as arteries, veins are extremely thinned walled due to absent of muscular tissue in walls, and posses no valves