22.6 Anat: Circulation of the CNS Flashcards
(13 cards)
Where is the highest demand for blood flow in the brain?
In the cortex where the cell bodies sit
How much of cardiac output does the CNS need?
10-20%
What comprises the Circle of Willis? Where do these vessels travel?
Vertebral basilar-transverse foramina and foramen magnum (from subclavian)
Internal carotid-carotid canal (from common carotid)
Draw the circle of Willis
Include the ACeA, ACA, MCA, PCeA, PCA, ICA
What does the ACA supply? What would we see if it was blocked?
ACA: medial part of frontal/parietal
Motor/sensory cortices for lower limb
Blocked: contralateral hemianaesthesis/spastic paralysis
What does the MCA supply?
Lateral brain (frontal/parietal/temporal/occipital/insula parts)
Motor/sensory cortices for most of body (NOT lower limb), parietal-occipital association areas and language areas
What does the PCA supply?
Medial and inferior surfaces-temporal/occipital lobe
Territories incl. visual cortex
Block: lose contralateral visual field
What do the small perforating branches supply?
Anterior: optic chiasm/hypothalamus
Lenticulostriate arteries: basal ganglia and internal capsule
Ventral midbrain: post hypothalamus/thalamus
Pontine branches: ventral pons
Where does the ophthalmic artery run?
Passes into orbit (incl. retina), top of nasal cavit and frontal scalp
What does the anterior choroidal artery supply?
Structures in deep lateral hemispheres, optic tract, lateral ventricles, hippocampus
What supplies the midbrain, pons and medulla?
Midbrain: basilar A–>PCA
Pons: pontine branches
Medulla: anterior spinal artery (midline), vertebral art. (ant/lat), cerebellar art (post./lat)
What is medial medullary syndrome?
Accident associated with anterior spinal artery
Lose: pyramids, medial lemniscus and XII
=alternating hemiplegia
What is lateral medullary syndrome?
PICA occlusion
- Contralateral sensory deficits (trunk, extremities)
- Ipislateral sensory deficits (face)
