Unit 4: Blood Supply Of The Spinal Cord And Brain Pg 145 - 152 Flashcards
Brain is _% of body weight
2
Brain requires _% cardiac output
17
Brain consumes _% oxygen used by entire body
20
30 seconds without blood in the brain =
Metabolism is altered
60 seconds without blood in the brain =
Neuronal function may cease
5 minutes without blood in the brain =
Cerebral infarction may occur
Ischemia, if untreated, can do what to the brain
Soften and liquefy (liquefactive necrosis)
A condition with an abrupt onset of neurological deficits caused by ischemia or hemorrhage in brain tissue as a result of vascular disease
Stroke
Causes of vascular lesion: arterial occlusion, cerebral arterial hemorrhage, aneurysm
Paired arteries found along most of the length of the spinal cord
Posterior spinal arteries
Posterior spinal arteries exit cranial vault through what foramen?
Foramen magnum
Generally unpaired arteries found along most of the length of the spinal cord
Anterior spinal artery
From the arterial vasa corona, branches are given off to supply the cord:
Sulcus branches — enter v-m fissure and supply deep cord areas
Penetrating branches — supply peripheral parts of the cord and deep parts of the spinal cord
Spinal arteries supply small branches into the pia that form the ___ around the spinal cord
Arterial vasa corona
Blood of anterior spinal origin supplies 2/3 of anterior cord, including grey matter areas:
Ventral horn
Lateral horn
Intermediate zone
Blood of anterior spinal origin supplies 2/3 of anterior cord, including white matter areas:
Ventral funiculus
Lateral funiculus
Blood of posterior spinal arteries supply the posterior 1/3 of the cord including which gray and white matter areas?
Most of dorsal horn
Dorsal funiculus
Segmental arteries (e.g., vertebral, intercostal, lumbar) give rise to
Spinal branches of segmental arteries
Spinal branches of segmental arteries enter vertebral canal through what?
IVF
Spinal branches of segmental arteries give off dorsal and ventral branches called:
Anterior radicular arteries and posterior radicular arteries
Anterior and posterior radicular arteries travel along:
Associated rootlets fo spinal nerves (either anterior/ventral or dorsal/posterior)
Radicular arteries are small and supply
Nerve rootlets
Some radicular arteries are large and anastomoses with
Anterior or posterior spinal arteries
Note: 9-12 anterior radicular arteries join the anterior spinal artery
Note: 14 total posterior radicular arteries join the posterior spinal arteries
Most large radicular arteries are in what parts of the spinal cord
Lower cervical, lower thoracic and upper lumbar
Vertebral arteries give rise to 3 branches:
Anterior spinal artery (medially)
Posterior spinal arteries (medial and inferiorly)
Posterior Inferior Cerebellar Artery — or PICA (superiorly and laterally)
PICA supplies what part of the cerebellum and what part of the medulla?
Posterior-inferior cerebellum
Medullary branches to dorsolateral medulla
Occlusion of PICA (or vertebral artery or medullary branches of PICA) can result in
Lateral medullary syndrome aka Wallenberg’s syndrome (review pg. 45 of note packet)
Branches of the basilar artery from inferior to superior:
Anterior inferior cerebellar artery — AICA
Internal auditory artery = labyrinthine artery
Pontine arteries (supply basilar pons)
Superior cerebellar arteries
CN III
Posterior cerebral arteries
Posterior communicating arteries (vertical, communicate with internal carotid aa)
What artery travels through internal acoustic meats to supply auditory and vestibular receptors of the inner ear?
Internal auditory artery
Occlusion of Internal auditory artery?
Deafness on affected side and vestibular dysfunction
Pontine arteries supply
Basilar pons
Superior cerebellar arteries supply
Superior surface cerebellum and SCPs
Posterior cerebral arteries are terminal branches of
Basilar artery
What artery passes around midbrain, superior to the tentorium cerebellum and along the medial and inferior surface of the temporal and occipital lobes?
Note: recall from gross II that the tentorium cerebelli is the shallow tent-like shape of the faux cerebri. The tentorium cerebelli intervenes between occipital lobes and cerebellum.
Posterior cerebral arteries
Posterior cerebral arteries supply what structures:
Base of cerebral peduncle
Occlusion of base of cerebral peduncle leads to
Posterior thalamus
Tectum of midbrain
Posterior corpus callous
Inferior surface of temporal lobe including hippocampus
Medial and inferior surface of the occipital lobe
A strip of temporal and occipital cortex along the lateral surface
Lesion of the primary visual cortex leads to
Cortical blindness on contralateral side
Contralateral homonymous heminopsia
Posterior communicating arteries connects what 2 arteries?
Posterior cerebral artery and internal carotid artery
What arteries traverse the cavernous sinuses and approach the brain just lateral to the optic chiasm?
Internal carotid arteries
Internal carotid arteries branches include:
Hypophyseal branches
Opthalmic artery
Anterior choroid always artery
Anterior cerebral artery
Middle cerebral artery
What artery supplies corpus callous, Cingular gyrus, cortex of medial surface parietal lobes, medial and inferior surface of the frontal lobe including the olfactory bulbs and tracts
Anterior cerebral artery
Occlusion of Anterior cerebral artery results in
Deficits in contra lower extremity:
— loss of somatosensation
— spastic paralysis of contra lower extremity
— urinary incontinence
What artery travels along optic tract?
Anterior choroidal artery
What artery supplies uncut, amygdala, optic tract, some hippocampus, some LGB of thalamus?
Anterior choroidal artery
The middle cerebral artery enters the lateral sulcus to give rise to:
Lenticulostriate arteries
Lenticulostriate arteries supply:
Corpus striatum
Much of internal capsule
Occlusion of internal capsule
Various sensory and motor disturbances
The middle cerebral artery supplies functional areas that include:
▫ auditory cortex (primary and associative)
▫ primary motor - except for lower extremity and trunk
▫ premotor - including frontal eye field (FEF)
▫ primary somatosensory except for lower extremity and
trunk
▫ in the dominant hemisphere - sensory and motor
language centers
Occlusion of middle cerebral artery can result in:
— slight decrease in hearing in both ears
— spastic paralysis of contralateral upper extremities and
muscles of facial expression on contralateral ½ face (and maybe tongue)
— loss of voluntary gaze to the contralateral side
— loss of somatosensation of contralateral upper extremity and
contralateral face
What arteries make up the cerebral arterial circle of Willis?
— anterior communicating artery — anterior cerebral arteries — internal carotid arteries — posterior communicating arteries — posterior cerebral arteries
What is the clinical significance of the cerebral arterial circle of Willis?
With occlusion of one ore more arteries in the circle, there may be some alteration of blood flow from one of the anastomosing vessels
