Page 410 - Atlas of Histology with Functional Correlations

the tunica media (3). Surrounding the tunica media (3) is the connective tissue

layer of tunica adventitia (4).

Adjacent to the small artery (1) is a small vein (6) with a larger lumen that is
filled with blood cells. The wall of the vein (6) is thinner in comparison to that of
the artery (1) but also consists of tunica intima (7) composed of endothelium
(7a), a thin layer of circular smooth muscle tunica media (8), and the layer of

connective tissue tunica adventitia (9).

FIGURE 10.9 ■ Artery and vein in the dense irregular connective tissue of the

vas deferens. Stain: iron hematoxylin and Alcian blue. ×64.

FIGURE 10.10 | Wall of Elastic Artery: Aorta

(Transverse Section)

The wall of the aorta is similar in morphology to that of the artery illustrated in
Figure 10.9. Instead of smooth muscle fibers, the elastic fibers (4) constitute the
bulk of the tunica media (6), with smooth muscle fibers (10) less abundant

than in the muscular arteries. The arrangement of the elastic fibers (4) in the
tunica media (6) are demonstrated with the elastic stain. Fine elastic fibers and
smooth muscle fibers (10) are either lightly stained or remain colorless.

The simple squamous endothelium (1) and the subendothelial connective

tissue (2) in the tunica intima (5) are indicated but remain unstained. The first
visible elastic membrane is the dark-stained IEL (membrane) (3).

The tunica adventitia (7), less stained with elastic stain, is a narrow,
peripheral zone of connective tissue. A venule (9a) and an arteriole (9b) of the

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