Blood Supply to the Nervous System Flashcards
which two paired arteries are responsible for the blood supply to the brain?
vertebral and internal carotid arteries
describe the circle of Willis
the joining area for the internal carotid and vertebral arteries
what is 9?
basilar artery
what is 10?
labyrinthine artery
what is 11?
anterior inferior cerebellar artery
what is 12?
posterior inferior cerebellar artery
what is 13?
vertebral artery
what is 14?
anterior spinal artery
from which arteries do the left and right vertebral arteries arise?
subclavian artery
at what vertebral level do the left and right internal carotid arteries arise?
C4
how is the basilar artery formed and which part of the brainstem is it most closely related to?
formed via joining of vertebral arteries and related to pons
which arteries complete the posterior Circle of Willis by linking the internal carotid arteries to the posterior cerebral arteries?
posterior communicating artery (6 on diagram)
which artery completes the anterior Circle of Willis by linking the anterior cerebral arteries?
anterior communicating artery (2 on diagram)
identify the three cerebral arteries. In which fissure/groove/sulcus of the brain do they travel?
- anterior cerebral artery > anterior and medial aspect of the median longitudinal fissure.
- middle cerebral artery > travels from base of brain through lateral sulcus.
- posterior cerebral artery > travels in calacrine fissure as calcarine artery.
which artery/arteries supplies the primary motor cortex?
anterior and middle (mostly) cerebral arteries
which artery/arteries supplies the primary sensory cortex?
middle cerebral artery
which artery/arteries supplies the primary visual cortex?
calcarine artery branch of posterior cerebral artery
which artery/arteries supplies the primary auditory cortex?
middle cerebral artery
which artery/arteries supplies the area for olfaction?
anterior cerebral artery
which parts of the brain does the vertebro-basilar system supply?
brainstem, occipital lobes, cerebellum
which cerebral artery runs immediately superior to the superior cerebellar arteries?
posterior cerebral artery
which cranial nerve emerges from just above the superior cerebellar artery?
oculomotor III
what are the clinical manifestations of palsy of CN III?
- down and out ocular positioning with abduction, slight depression and intorsion.
- complete ptosis due to neuropathy affecting levator palpebrae superioris.
describe the carotid sinus and its function
- a dilatation located on the terminal part of the CCA (or the proximal part of the ICA).
- pressure receptor which monitors the flow of blood to the head, including the brain.
- sensory nerves from the carotid sinus run in the glossopharyngeal and vagus nerve.
describe the carotid body and its function
- an area on the posterior wall of the terminal part of the CCA in the neck.
- conains chemoreceptors which are sensitive to low oxygen levels (anoxia).
- sensory nerves from these receptors run in the glossopharyngeal nerve.
- detection of anoxia will stimulate increased heart rate, respiration rate and blood pressure.
The brain is drained by a series of veins which drain into Dural venous sinuses. These sinuses are present between what structures?
the periosteum and the cranial dura
what is the highlighted structure and what does it drain?
- superior sagittal sinus
- drains the superior cerebral veins
label the larger intracranial venous sinuses
into which vein do the dural venous sinuses drain into?
IJV
the superior opthalamic vein drains into..
state for both within and outside cranial cavity
the cavernous sinus within the cranial cavity. On the outside of the cranial cavity, it is continous with the facial vein.
describe emissary veins
Emissary veins are valveless venous structures that connect the extracranial vessels of the scalp to the intracranial dural venous sinuses and diploic veins.
what veins drain into the cavernous sinus?
opthalamic veins
central vein of retina
sphenoparietal sinus
superficial middle cerebral vein
pterygoid plexus
which structures on the skull base is the cavernous sinus closely related to?
sella turcica of the sphenoid bone (which the pituitary gland sits upon).
branches from which arteries fuse to form the anterior spinal artery?
formed from branches of vertebral arteries
which arteries are the posterior spinal arteries branches of?
posterior spinal arteries originate from the vertebral artery or the posteroinferior cerebellar artery
which artery is A?
middle cerebral artery
which artery supplies the medial surface of the parietal lobe?
anterior cerebral artery
the vertebral arteries arise from which artery?
subclavian
what venous sinus lies at A?
straight sinus
