Blood supply to the central nervous system Flashcards
What percentage of body weight is the brain?
2%
What percentage of cardiac output goes to the brain?
10-20%
What percentage of the body’s oxygen consumption is the brain responsible for?
20%
What percentage of liver glucose is used by brain?
66%
What do all these statistics mean?
Brain is very vulnerable if blood supply is damaged
What are the two sources of blood to the brain?
Internal carotid arteries (front) and vertebral arteries (back)
What does the external carotid artery supply?
The face
What does the internal carotid supply?
Cerebral hemispheres
Where do the vertebral arteries originate from?
They branch off the subclavian arteries
Describe the vertebral arteries journey from the subclavian to the brain?
They go through the transverse foramina in the cervical vertebrae and through the foramen magnum into the brain
What do the vertebral arteries go onto form
Circle of Willis
What do the vertebral arteries join together to form?
Basilar artery
What does the basilar then bifurcate to form?
Posterior cerebral arteries
Where do the middle cerebral arteries originate from?
The internal carotid arteries travel superiorly and then laterally to form the middle cerebral arteries that emerge through the fissure between the frontal, parietal and temporal lobes
What do the internal carotid arteries also branch to form?
Anterior cerebral arteries that go up in between the two medial surfaces of the hemispheres and they follow the corpus callosum back about 2/3 of the way
This arrangement is made into the circle of Willis by how many posterior and anterior communicating arteries
Two posterior and one anterior
What are the four components of the brain involved in venous drainage
Cerebral veins
Venous sinuses
Dura mater
Internal jugular vein