Buckmaster's Elements of animal physiology / by John Angell.

  • Angell, John
Date:
1866
Catalogue details

Licence: Public Domain Mark

Credit: Buckmaster's Elements of animal physiology / by John Angell. Source: Wellcome Collection.

    354/384 (page 342)
    Co7'puscles^ consist of nucleated cells of various forms, designated, according to their respective shapes, as spheroidal, pyriform, or pear-shaped, caudate (tailed), and stellate (star-shaped). These bodies enter into the structure of the gcinglia, and are therefore some- times termed ganglionic cells or corpuscles. The cortical substance of the brain and the interior of the ganglia consists principally of vesicular nervous matter. The nucleolus in the nucleus forms a most characteristic feature of the nerve-cell.—(See Fig. 97.) The nerve-cells probably generate, and the nerve- fibres simply conduct, nervous force. Serous Membranes consist of—i, an external layer of compact areolar tissue, less abundantly sup- plied with bloodvessels than the corresponding lamina in mucous membrane; 2, a middle layer of basement membrane, similar to that of mucous membrane; 3, an inner single layer of tesselated epithelium on its free surface. They are always kept moist by a liquid termed the serous fluid. The serous memh-anes form closed sacs, which line the interior of the great cavities of the head and trunk. The principal serous membranes are the arachnoid membrane, which lines the cavity of the skull; the pleura, which lines the lungs and cavity of the chest; the pericardium, which lines the heart; and the peritoneum, which lines the interior of the cavity of the abdomen. The serous sacs are closed sacs, one half of which is folded or tucked into the other, so as to form, as it were, an inner lining which rubs against the outer portion. The outer layer, which is attached to the walls of the cavity in which it is placed, is termed the parietal layer; the inner receives the organ to the surface of which it is everywhere attached, forming its lining membrane, and is termed the visceral layer. Their inner, free, or epithelial surfaces, which rub together, are moistened to reduce friction. When these membranes become inflamed, they tend to throw out large quantities of a liquid termed coagulable lymph, which sometimes, as in pleuritis, joins the two walls together, producing what are in surgical