Neuro Lecture 5 Flashcards
Fibrous layer surrounding, protecting and nourishing the CNS
Meninges
Large Diameter valveless venous vessels
Venous Sinus
Pathological reduction of blood supply
Ischemia
localized pathological dilation of a blood vessel, usually caused by atherosclerosis and hypertension, or, less frequently, by trauma, infection or congenital weakness
Aneurysm
How many layers are there in the cranial meninges?
Dura Mater (two layers), arachnoid and pia mater
Dural folds between the major subdivisions of the brain forming large septa is called what?
Falx cerebri
What lies in-between the two layers of dura mater?
Dural venous sinuses
Is arachnoid mater vascular or avascular?
avascular (so hence pia mater is SUPER vascular)
what arteries lie between the arachnoid and the pia mater?
cerebral arteries
How would an epidural hemorrhage show up on a CT scan?
A biconvex mass in the epidural space
what artery is ruptured in an epidural hemorrhage?
middle meningeal artery
Describe to me an scenario where someone would present to the ER with an epidural hemorrhage (include AGE)
Young (note just not old) male at football practice was hit in the head. states that he initially did experience some loss of consciousness but then felt fine.
Explain what will happen to a patient if an epidural hemorrhage goes without medical attention?
the high pulsation of the artery starts peeling away the dura from the suture line and volume starts to expand and the brain will start to herniate.
What would you see on a CT scan to confirm a subdural hemorrhage?
crescent shaped subdural mass
Does a subdural hemorrhage normally affect old or young ppl? give a reasoning for your answer
old ppl. because as we get old our brains shrink and therefore the veins start to stretch and any minor trauma can tear those veins.
Why is a subdural hemorrhage considered a slow bleed?
because the pressure in the venous system is much lower than in the arterial system.
what is a defining feature of a subarachnoid hemorrhage on a CT scan?
the bleed takes the shape of Gyri and Sulci, making a tree like appearance.
where is the location of the vessels that rupture in a subarachnoid hemorrhage?
between the arachnoid and pia mater
is a subarachnoid hemorrhage, trauma based or spontaneous?
both ;)
what vessels rupture in an intracerebral hemorrhage?
rupture of the intraparenchymal branches of subarachnoid arteries, such as the lenticulostriate arteries
Two pairs of arteries enter the skull, deliver blood to the brain. what are they?
internal carotid and vertebral arteries
what level in the body does the common carotids bifurcate to yield the external and internal carotid arteries
thyroid cartilage
what two arteries does the internal carotid artery emit?
ophthalmic and posterior communicating arteries and then these terminate as the anterior and middle cerebral arteries
where do they vertebral arteries enter the skull through?
foramen magnum
what arteries does the vertebral arteries emit?
posterior inferior cerebellar arteries (PICA), which usually spawn the posterior spinal arteries and the anterior spinal artery.
the basilar artery gives rise to what arteries?
AICA and superior cerebellar arteries
where does the posterior communicating artery arise from?
the junction of the internal carotid and middle cerebral arteries.
the anterior cerebral artery arches laterally over the edge of the hemisphere to serve which medial regions of the brain?
medial regions of the frontal and parietal lobes. additionally the septum pellucid and the corpus callosum
the posterior cerebral artery serves which parts of the brain medially?
medial occipital, temporal, and parietal lobes
describe the path of the internal carotid artery
ascend through the deep neck, the carotid canals of the petrous bones, and cavernous sinus. ends just lateral to the optic chiasm
what does the middle cerebral artery supply?
lateral aspect of frontal, temporal, and parietal lobes.
the middle cerebral artery emits the lenticulostriate arteries during its course, what areas of the brain do these arteries target?
the basal ganglia and the internal capsule
what artery connects the posterior cerebral artery to the internal carotid artery circulation?
posterior communicating artery
what is the terminal branch of the basilar artery?
posterior cerebral artery
Occlusion of the left middle cerebral artery would yield what deficits?
language
what artery supplies blood to the ventral cord of the spinal cord?
Anterior spinal artery
what artery supplies blood to the dorsal and lateral aspect of the spinal cord?
two posterior spinal arteries
what is an arterial vasocorona?
the anterior spinal artery has anastomotic connections to both posterior spinal arteries, forming an arterial vasocorona
how does the lateral aspect of the spinal cord receive blood?
via an anastamotic plexus of segmental arteries that emit spinal medullary and radicular arteries.
why does the brain consume 20% of oxygen?
high metabolic rate and therefore high oxygen requirement
what percent of the cardiac output is supplied to the brain?
15%
anesthesia that is injected into the epidural space causing conduction blockage of adjacent spinal nerves
epidural anesthesia
what results from an occlusion of a vessel by a clot, cells, gas, etc?
embolism
