3B Scientific 3B MICROanatomy™ Artery and Vein -14-times enlarged - Manual (Page 2)

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3B MICROanatomy™ Artery and Vein
English
The model shows a medium-sized muscular artery with two adjacent veins from the antebrachial area with
adjoining fat tissue and muscle enlarged 14 times. The model illustrates the reciprocal anatomical relation-
ship of artery and vein and the basic functional techniques of the venous valves (“valve function” and
“muscle pump”).
The left vein and the middle artery are fenestrated in the upper anterior segment, revealing the various
layers of the wall structure in a cross and longitudinal section and in top view.
The thickness of the wall layers depends on the local particularities.
The individual wall layers of the vein are structured as follows from the interior to the exterior:
• The tunica intima consists of an endothelium, a subendothelial layer of connective tissue and an internal
elastic lamina.
• The tunica media contains both smooth muscle cells and loose connective tissue fibers.
• The tunica externa (or tunica adventitia) consists of loose connective tissue, smooth muscle cells and vasa
vasorum.
The individual wall layers of the artery are structured as follows from the interior to the exterior:
• The tunica intima consists of an endothelium, the subendothelial layer of connective tissue and the
internal elastic lamina.
• The adjacent tunica media consists almost mainly of circularly arranged smooth muscle cells and
connective tissue fibers.
• The tunica externa (or tunica adventitia) consists of the lamina elastica externa, an elastic fibrous layer,
connective tissue and vasa vasorum.
The right vein is opened throughout in the anterior segment, revealing the orifice of a feeder vein and two
venous valves, i.e. “flap valves” formed by a duplication of the tunica intima.
On the rear of the model, the relief of two veins is shown to illustrate the functional aspect of the venous
valves. The left vein, with one opened and one closed venous valve, illustrates the physiological (proper)
valve function. In comparison, the two venous valves of the right vein function insufficiently and the vessel
as a whole is dilated, as seen in a varicose vein.
A Vein
Tunica intima
1 Endothelium
2 Subendothelial layer of connective tissue and basal lamina
3 Internal elastic lamina
4 Tunica media
5 Tunica externa and vasa vasorum
6 Venous valve
B Artery
Tunica intima
7 Endothelium
8 Subendothelial layer of connective tissue and basal lamina
9 Internal elastic lamina
10 Tunica media
Tunica externa
11 External elastic lamina
12 Connective tissue with layer of elastic fibers and vasa vasorum
13 Fat pad
14 Muscle
15 Sectional view of a vein with physiological valve function
16 Sectional view of a vein with insufficient valve function (varicose vein)
Latin
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A Vena
Tunica intima
1 Endothelium
2 Textus connectivus subendothelialis et membrana basalis
3 Lamina elastica interna
4 Tunica media
5 Tunica externa et vasa vasorum
6 Valva
B Arteria
Tunica intima
7 Endothelium
8 Textus connectivus subendothelialis et membrana basalis
9 Lamina elastica interna
10 Tunica media
Tunica externa
11 Lamina elastica externa
12 Textus connectivus cum fibrae elasticae et vasa vasorum
13 Corpus adiposum
14 Musculus
15 Sectional view of a vein with physiological valve function
16 Sectional view of a vein with insufficient valve function (varicose vein)