Page 405 - Atlas of Histology with Functional Correlations
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of fine collagen and elastic fibers that blend with the connective tissue of the
tunica media (11b).
Tunica media (11b) consists of a thin layer of circularly arranged smooth
muscle embedded in connective tissue. Tunica media (11b) is much thinner
in veins than in arteries (5).
Tunica adventitia (11c) exhibits a wide layer of connective tissue, and in
veins, the tunica adventitia (11c) layer is thicker than the tunica media (11b).
Two arterioles (2, 8) are cut in different planes. The arterioles (2, 8) have a thin
IEL and a layer of smooth muscle fibers in the tunica media. One arteriole (8) is
shown cut in longitudinal plane with a branching capillary (10). An arteriole (8)
cut at an oblique angle shown only the circular smooth muscle layer of the tunica
media. Also visible are capillaries (10) sectioned in longitudinal and oblique
planes and small nerves (1) in transverse planes.
The lymphatic vessels (12, 13) exhibit the thinnest walls. When cut in a
longitudinal plane, the flaps of a valve (13) are seen in the lumen of the
lymphatic vessel. Many veins in the arms and legs have similar valves in their
lumina.
Numerous adipose cells (14) are found in the surrounding connective tissue.
FIGURE 10.4 ■ Blood and lymphatic vessels in the connective tissue. Stain:
hematoxylin and eosin. Low magnification.
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