These arteries conduct blood steadily
and uniformly away from the heart, using the recoil generated by
their thick elastic walls. Examine these sections of the aorta (sample
1, sample 2 and
sample 3),
an example of an elastic artery, and identify the following:
The three basic layers or tunics
(intima, media, and adventitia)
Endothelium lining the intima
Elastic lamellae and smooth
muscle cells within the media
CT and vasa vasorum and nervi
vascularis in the adventitia
Clinical
note: Degeneration of components such as elastic fibers in the
tunica media of arteries weakens the arterial wall and can lead to
formation of a circumscribed bulge called an aneurysm and blood
leakage into or through the wall (a “dissected” artery). Either type
of defect can have disastrous results in a major artery such as the
aorta.
and
Clinical
note: Degeneration of components such as elastic fibers in the
tunica media of arteries weakens the arterial wall and can lead to
formation of a circumscribed bulge called an aneurysm and blood
leakage into or through the wall (a “dissected” artery). Either type
of defect can have disastrous results in a major artery such as the
aorta.