Lecture 23 Flashcards
Describe anatomy of vascular supply
-Common carotid artery common off either side of aorta. Common carotid artery feed: external and internal carotid artery (splits once it gets to neck). External carotid to external face, internal runs through corotid forman into base of skull.
-Internal corotid branches to: anterior cerebral artery (ACA) and middle cerebral artery (MCA)
-off subclavian artery have vertebral arteries which run up through foramen transversa (holes in transverse processes). Run through foramen magnus and along anterior surface of brainstem, at medulla fuse to form basilar artery.
-basilar artery and then forms: posterior cerebral artery (PCA) on left and right side which supply to posterior part of brain
Describe structures that make up the circle of willis
-anterior communicating artery- connects blood between right and left ACA
-posterior communicating artery- connects blood between posterior cerebral artery and internal carotid on same side
Describe travel of blood
-once cerebral arteries off internal carotid or basilar artery-> out to other areas of the brain, travelling through subarachnoid space
Describe regions of cortex supplied by ACA
-anterior cerebral artery travels in interhemispheric fissure and supplies superior and medial cortex from frontal lobes and anterior parietal lobes
Describe regions of cortex supplied by PCA
-from interhemispheric fissure supplies inferior and medial temporal lobe and occipital lobe
Identify the three divisions of the middle cerebral artery
superior, inferior and deep divisions
Describe areas of cortex supplied by superior division of MCA
-superior edge of sylvian fissure, supplied lateral aspect of frontal lobe and anterior-parietal lobe
Describe areas supplied by inferior division of MCA
-inferior side of sylvian fissure supplieds anterolateral aspect of temporal lobe and posterior parietal cortex
Describe areas supplied by deep division of MCA
-deep branches of MCA feeds parts of basal ganglia: body of caudate, most of lentiform nucleus (putamen, plobus palidus)
Describe areas supplied by deep branch of PCA
thalamus
Describe venous return of blood
-Once blood is used, veins throughout subarachnoid space feed into smaller bridging veins which dump into sinuses, and eventualluy back to the heart
Describe types of vascular injury
-blockage/occlusions:
-Thrombus: blood clot forms around plaque and limits blood supplu
-Embolism: materials from somewhere else clogs artery and causes embolism, often a blood clot originating from elsewhere and travels to brain and gets clogged.
-hemmorage:
-ruptured aneurism: arterial wall bursts caused by weakness and blood leaks out-> leads to blood not getting where it needs to go and leads to subarachnoid hematoma
Consequences of vascular injury
-depending on where the block or bleed occurs will depend on symptoms
