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Peripheral Vasculature Diseases – Section 1 DISEASES OF THE AORTA
First, some general review of the aorta: The largest conductance vessel of the vascular system Can break it down into four sections:
5-6 cm in length three major branches
Descending aorta Abdominal aorta
o brachiocephalic (bifurcates to give right common carotid and right subclavian) o left common carotid o left subclavian from arch, the diameter narrows to 2-2.5 cm subdiaphragmatic provides arteries to abdominal viscera bifurcates into left and right common iliacs, which supply the pelvic organs and lower extremities
Section of Aorta Ascending aorta
Details 3 cm diameter at base of heart (LA)
Aorta is an artery…it is composed of:
internal elastic lamina
smooth muscle cells
matrix including elastic fibers and collagen, respectively for stretching and strength – in aorta, ratio of elastin to collagen is 2:1, allowing aorta to expand during systole and recoil during diastole
external elastic lamina
vasa vasorum supplies oxygenated blood to the aorta
Aorta’s recoil against the closed aortic valve during diastole is what promotes forward propagation of blood flow.
with age, get degeneration of the elastic fibers of the aorta and its branches – collagen becomes
more prominent and arteries stiffen
increased systolic blood pressure
Aorta, thus, with age is subject to injury from mechanical trauma due to high pulsatile pressure
and shear stress.
Diseases of the aorta commonly appear as aneurysm, dissection, or obstruction.
Aneurysm and dissection are discussed in the text…I will elaborate on them in colored text boxes