Volume 2

An introduction to the study of human anatomy / [James Paxton].

  • Paxton, James, 1786-1860
Date:
1831-1834
Catalogue details

Licence: Public Domain Mark

Credit: An introduction to the study of human anatomy / [James Paxton]. Source: Wellcome Collection.

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    tensive than the other, commences in the head, trunk and limbs, and transmits the blood to the heart by the veiue cavie. The 2nd, or abdominal department of the venous system, is confined to the cavity of the abdomen, and re¬ ceives its blood from the arteries of the digestive organs and spleen, and terminates in the vena portae, which sub¬ divides and distributes the blood through the liver. The veins are far more numerous, and, considered as a whole, they are much more capacious than the arteries. The distribution of veins is somewhat similar to that of the arteries ; each artery is accompanied by a vein, the size of which is greater than the artery, and frequently the artery is associated with two veins. In general a cellular space, common to all, receives both the trunks of the two species of vessels and those of the nerves. In the head, limbs, and every other part, there are two sets of veins; the su¬ perficial and the deep seated: the 1st lie immediately under the skin, or run above the fasciae; the 2nd, or deep seated veins directly attend the arteries. The union be¬ tween the branches of the veins is very frequent; they communicate in right lines or in arches, and the smaller are so multiplied as to form complicated meshes of net¬ work; but the minute ramifications of veins ultimately form an inconceivable number of small canals in the tissue of organs, of such extreme tenuity, as to render it im¬ possible to understand their final distribution. STRUCTURE OF VEINS. The veins are formed of only two membranes; the outer is composed of longitudinal fibres, very easily distinguished in the large trunks, and surrounded by a sheath of cellular tissue, the layers of which are placed very densely on each other. The inner membrane is thin, smooth, and glossy;