Lecture 19 + 20 (Blood Supply) Flashcards
Arterial systems
- Common carotid artery (thick)
- Vertebral artery (thin)
Common carotid
- internal carotid artery
- external carotid artery
Internal carotid
Enter cranium through carotid canal of temporal bone, through dura mater and into arachnoid at base of brain
- Ophthalmic artery
- Anterior choroidal artery
- Anterior cerebral artery (ACA)
- Middle cerebral artery (MCA)
Vertebral-basilar system
Branches supply blood to spinal cord, brainstem and cerebellum
Basilar artery
- Supplies brainstem and cerebellum
- Distal blood flow to thalami and medial temporal and parietal lobes
Circle of Willis (CoW)
Found around optic chiasma and pituitary gland
- 2 internal carotid arteries (ICAs)
- horizontal segments of anterior cerebral arteries (ACAs)
- anterior communicating artery (ACommA)
- 2 posterior communicating arteries (PCommAs)
- horizontal segments of both posterior cerebral arteries (PCAs)
- basilar artery (BA)
Vessels arise from the CoW
- anterior cerebral arteries (ACAs)
- middle cerebral arteries (MCAs)
- posterior cerebral arteries (PCAs)
Anterior cerebral arteries (ACA)
- Pre- and supplementary motor cortex
- M1 and S1 relating to lower limbs
- Cingulate gyrus
- Anterior 2/3 of corpus callosum
Middle cerebral artery (MCA)
- Pre- and supplementary motor cortex
- M1 and S1 relating to upper limbs, head and face
- Broca area
- Primary auditory area
- Wernicke area
Posterior cerebral artery (PCA)
- Primary and association visual cortex
- Inferior temporal gyrus
- Limbic structures, uncus, hippocampus
Blood supply to the brainstem
Range of vessels
Blood supply cerebellum
Top: superior branch basilar artery (SCA)
Middle: caudal branch of basilar artery (AICA)
Bottom: branch of vertebral artery (PICA)
Pontine branches
Blood route
Heart - Aorta - Large artery - Small artery - Arteriole - Capillaries - Venule - Vein - Vena Cava (Superior for brain route) - Heart
Cerebrovascular disorder
- Cerebrovascular accidents (CVAs) or strokes
– ischaemic (85%) (block in blood flow)
– haemorrhagic (15%) (break in blood vessel) - Aneurysm
Thrombosis
Obstruction blood vessel caused by locally forming blood clot
Embolism
Obstruction blood vessel caused by embolus formed elsewhere
Subdural hematoma
Collection of blood below inner layer of dura but external to arachnoid and brain
- Most common type of traumatic intracranial mass lesion
Cerebral/intracranial aneurysms
A local balloon-like dilation of an artery
- Congenital defect or result of disease that weaken arterial wall
- Eventually rupturing and bleeding (subarachnoid space)
