| spider nevus | A branched growth of dilated capillaries on the skin, resembling a spider. This abnormality may be associated with cirrhosis of the liver. (27 Sep 1997) |
|---|---|
| spider pelvis | Narrow calices of renal pelvis. (05 Mar 2000) |
| spider's web | <zoology> The silken web which is formed by most kinds of spiders, particularly the web spun to entrap their prey. See Geometric spider, Triangle spider, under Geometric, and Triangle. Source: Websters Dictionary (01 Mar 1998) |
| spider telangiectasia | spider angioma |
| spider venoms | Venoms of arthropods of the order araneida of the arachnida. The venoms usually contain several protein fractions, including enzymes, haemolytic, neurolytic, and other toxins. (12 Dec 1998) |
| acromial arterial network | A vascular network between the acromion and the skin of the shoulder, formed by anastomoses of the acromial branch of the suprascapular artery with the acromial branch of the thoracoacromial artery. Synonym: rete acromiale, acromial plexus. (05 Mar 2000) |
| alveolar-arterial oxygen difference | The difference or gradient between the partial pressure of oxygen in the alveolar spaces and the arterial blood: P(A-a)02. Normally in young adults this value is less than 20 mm Hg. See: alveolar gas equation. (05 Mar 2000) |
| arterial | <anatomy> Pertaining to an artery or to the arteries. (18 Nov 1997) |
| arterial arcades | A series of anastomosing arterial arches, as the intestinal arterial arcades between the branches of the jejunal and ileal arteries in the mesentery and the pancreaticoduodenal arteries on the head of the pancreas. (05 Mar 2000) |
| arterial arches of colon | Anastomosing branches of the colic arteries that form arch's in the mesocolon from which the walls of the colon are supplied. See: marginal artery of colon. (05 Mar 2000) |
| arterial arches of ileum | Arches formed in the mesentery by branches of the superior mesenteric artery from which vessels (vasa recta) arise to supply the wall of the ileum. See: intestinal arterial arcades. (05 Mar 2000) |
| arterial arches of jejunum | Arch's formed in the mesentery by branches of the superior mesenteric artery from which vessels (vasa recta) arise to supply the walls of the jejunum. See: intestinal arterial arcades. (05 Mar 2000) |
| arterial arch of lower eyelid | Formed by the medial palpebral artery which communicates with a branch of the lacrimal artery along the tarsal margin. Synonym: arcus palpebralis inferior. (05 Mar 2000) |
| arterial arch of upper eyelid | Formed by communicating branches of the medial and lateral palpebral arteries. Often two arches are present, one located near the free border of the tarsal plate, the other along the upper border of the tarsus. Synonym: arcus palpebralis superior. (05 Mar 2000) |
| arterial blood | Blood that is oxygenated in the lungs, found in the left chambers of the heart and in the arteries, and relatively bright red. (05 Mar 2000) |