Lab 7 Cardiovascular System: 1) Index 2) Introduction 3) Things to identify 4) Muscular Arteries ... 5) Arterioles 6) Elastic Arteries 7) Capillaries 8) Medium Sized Veins 9) Large Veins 10)Venules .. 11) Lymphatic Vessel 12) Heart 13) Practical

 

Large Veins

 

# 74 - Artery and vein, monkey, c.s., h-e, 1.5 mm

# 76 - Artery, vein, and nerve, monkey, c.s., h-e, 1.5 mm

 

These slides have a section through one of the large veins of the body, such as the vena cava. Identify the three tunics. Observe smooth muscle fibers in the tunica intima that are oriented in a longitudinal direction.

Sometimes you may see a valve in a large vein and if one is visible, see if you can identify the lining cells (endothelium) and its underlying connective tissue.

The media of a vein has only a little smooth muscle and the adventitia is thick, with an inner layer of dense collagen fibers, then a longitudinally oriented muscular layer interlaced with collagen fibers, and outermost, a layer of collagenous and elastic fibers.

In the adventitia, locate the vasa vasorum.

References: Gartner, p. 159, Fig. 4 Ross, p. 316, Fig. 12.12 (diagram) Wheater, p. 151, Fig. 8.20


Here is a shot of some large vessels. Can you guess which one is the artery and which is the vein? The red arrow is pointing to the artery, which has it's thick tunica media, rigid structure and an obvious internal elastic lamina. The blue arrow is pointing to the Large Vein. Notice how thin the tunica media is (green arrow) compared to that of the artery. Functionality plays a role in why there is not a lot of smooth muscle or a large tunica media needed in the vein but necessary in the artery.

Red arrow - Large artery

Blue arrow - Large Vein

Green Arrow - Tunic Media

 

This is another example of a Large Artery , (red arrow) and Large Vein (blue arrow). Notice the obvious difference in rigidity in the artery and the vein. The Artery is held open because of it's structure and the vein is collapsed from it's flimsy structure.

 

Blue arrow - Vein

Red arrow - Artery

Artery and Vein

Artery and Vein