Vascular Ch 18 gross anatomy, physiology, and fluid dynamics of the cerebrovascular system

what are three layers of vasculature

tunica adventitia, media, intima

what is each vascular layer made up of

adventitia=elastic lamina; media=smooth muscle; intima=elastic lamina lined by 1 cell thick endothelial

what is first branch off ascending aorta

right and left coronary arteries

what is aortic arch formed from and where does it end

from ascending arch to descending aorta

what is first branch off aortic arch

innominate

what are 2nd and third branches off aortic arch

left common carotid, left subclavian

what does innominate branch into

right subclavian and right CCA

right common carotid bifurcates into…

internal and external carotid arteries

what is included in anterior pathway of cerebrovascular flow

CCA to ICA&ECA to front of brain

what is included in posterior cerebrovascular flow

vertebrals and basilir artery

what are other pathways in event of major pathway blockage

periorbital circulation, collateral pathways

is internal or external carotid larger

internal (more lateral and posterior)

what is first major branch of ICA

opthalmic artery

what does ICA branch into after entering the skull

opthalmic, anterior choroidal, posterior communicating

where does the ICA terminate

Middle cerebral artery and anterior cerebral artery

where does the ICA deliver blood to (what type of flow)

low resistance beds

the ICA receives ___ % of flow in the CCA

80%

where does ECA supply blood to

high resistance beds, neck, face, scalp

how many branches in ECA and what is first branch

8; superior thyroid artery

what is best way to distinguish ICA from ECA

ID branches of ECA

ECA may become collateral vessels if blockage

where do vertebral arteries arise from

subclavian arteries

where do vertebral arteries course

through transverse foramen of C6 to C1, unite to become basilar artery after entering skull through foramen magnum

is right or left vertebral artery larger

left

what does basilar artery divide to

posterior cerebral arteries to form circle of Willis

what forms circle of Willis

hexagon shape formed by anterior cerebral arteries in front, posterior cerebral arteries in back, ICAs

what connects circle of Willis anteriorly

anterior communicating artery

what connects the circle of Willis posteriorly

basilar artery divides into 2 PCAs; each joined to their ICA by a posterior communicating artery

what is the larges inter-arterial collateral pathway

circle of Willis

what is Bernoulli principle

velocity and pressure energy are inversely proportional (velocity, pressure)

what is Poisseulle’s law

re: volume = flow is parabolic or laminar- radius has large effect of volume (raised to the 4th), flow is related to pressure gradient across vessel

what is law of conservation of mass

velocity = (volume) flow divided by (cross section) area

how is turbulence detected on doppler

spectral broadening (wide range of frequencies)