Blood Supply and Cerebral Blood Flow Flashcards
(35 cards)
Which veins have little supporting structure and are vulnerable to injury forming a subdural hematoma?
Superior cerebral veins. These cross the subdural space (from arachnoid to superior sagittal sinus)
Which veins connect the dural sinuses (superior sagittal sinus or cavernous sinus) with extracranial veins of the scalp and face?
Emissary veins
Why do emissary veins have a greater potential for spreading infection (e.g. meningitis) from outside the cranium to venous sinesus within?
Emissary veins have no valves and allow for free communication between these venous systems
Veins of which features roughly follow the arterial system?
Veins of the brainstem, cerebellum and spinal cord
What is a potential consequence of the absence of valves in spinal cord veins?
Since there are no valves, flow is easliy reversed. This provides a means through which metastases from the pelvis, kidney, or lung may spread to vertebral bodies or to the CNS.
The brain, brainstem, and cerebellum are supplied by which two major arteries?
The internal carotid arteries and vertebral arteries.
Occlusion of these arteries or smaller branches causes damage to areas of the CNS supplied by these vessels.
Approximately what percentage of blood to the cerebrum is supplied by vertebral arteries?
15%. These vessels enter the foramen magnum, penetrate the dura mater and arachnoid; then enter the subarachnoid space.
Which arteries supply most of the brainstem through their branches?
vertebral arteries
The Anterior spinal artery (a single, unpaired artery) supplies blood to what part of the spinal cord?
It supplies blood to the anterior 2/3 of the spinal cord (running in a rostral to caudal direction in the ventral medial fissure of the spinal cord)
Which arteries branch off the vertebral artery; descend caudally as separate trunks and serve the posterior 1/3 of spinal cord?
The Posterior spinal arteries (paired)
Which arteries branch off the vertebral arteries before joining to form the basilar artery and provide blood to the posterior part of cerebellar hemispheres, vermis, and lateral and posterior medulla?
Posterior inferior cerebellar arteries
What are the four main branches of the basilar artery?
a. Anterior inferior cerebellar artery
b. Pontine arteries
c. Superior cerebellar arteries
d. Posterior cerebral arteries
The anterior inferior cerebellar artery (branch of the basilar artery) supplies blood mainly to which structures?
inferior cerebellum and deep cerebellar nuclei and part of the pons
The pontine arteries (branches of the basilar artery) supply blood mainly to which structures?
They penetrate the pons and supply this region of brainstem and all nuclei located there, including the reticular formation.
The superior cerebellar arteries (branches of the basilar artery) supply blood mainly to which structures?
They supply the dorsum of the cerebellum and deeper structures, midbrain, pons and superior cerebellar peduncle
The posterior cerebral arteries (branches of the basilar artery) supply blood mainly to which structures?
They supply the inferior surface of temporal lobe and medial occipital lobe to parieto-occipital fissure, thalamus, midbrain, internal capsule, cerebral peduncle, substantia nigra, and red nucleus.
What do the Posterior communicating arteries connect?
They connect the internal carotid system to the vertebral-basilar system; (and are part of the circle of Willis)
Which blood vessels are reponsible for supplying about 85% of the blood to the Cerebrum?
Internal carotid arteries
The internal carotid arteries branch to form which two main blood vessels?
Middle cerebral arteries and the anterior cerebral arteries
Middle cerebral arteries provide blood to…
the tip of temporal lobe, lateral surface of cerebral hemispheres and insula. Also supply globus pallidus, putamen, internal capsule, corona radiata, and caudate nucleus.
The MCA supplies all of the motor cortex (area 4) and the somatosensory cortex (areas 1, 2, 3) except the lower extremity LE area.
The anterior cerebral arteries are joined near the rostrom of the corpus callosum by…
the anterior communicating artery
The anterior cerebral arteries supply…
the medial surface of the cerebral hemisphere (i.e., the LE area) and deeper structures including the internal capsule, corpus callosum, and caudate nucleus.
Components of the circle of Willis:
A. Basilar artery B. Posterior cerebral arteries C. Posterior communicating arteries D. Internal carotid arteries E. Anterior cerebral arteries F. Anterior communicating artery
Blood supply of spinal cord (midline anterior spinal artery)
The midline anterior spinal artery, branches off the vertebral artery and supplies the anterior 2/3 of the upper cervical levels of the SC with blood from the vertebral artery.
