Elements of animal physiology, chiefly human . teries. The superjicial veins in general lie between the skinand the outside of the muscles. To stop a bleeding vein piessure should be applied tothe vein on the opposite side of the wound to which theheart is situated. 210. The veins are more numerous, larger, and thinnerwalled than the arteries ; they are consequently ^acczc^and collapsed, when empty, as we see them in joints fromthe butcher. When a vein is wounded, the blood issuesfrom it in a uniform continuous stream, quite unlike thejerking flow from the arteries. The veins difier from thear
Elements of animal physiology, chiefly human . teries. The superjicial veins in general lie between the skinand the outside of the muscles. To stop a bleeding vein piessure should be applied tothe vein on the opposite side of the wound to which theheart is situated. 210. The veins are more numerous, larger, and thinnerwalled than the arteries ; they are consequently ^acczc^and collapsed, when empty, as we see them in joints fromthe butcher. When a vein is wounded, the blood issuesfrom it in a uniform continuous stream, quite unlike thejerking flow from the arteries. The veins difier from thearteries also in being abundantly supplied with valves,which direct the blood towards the heart* 211. The Valves of the Veins consist in general oftwo or three pocket-sliaped pouches, or semi-lunar folds ofthe membranes of the inner and middle coats of thevein. Immediately behind the point of connection ofeach valve the vein is a little expanded to allow of thebloods getting behind and closing the valve when anyattempt at regurgitation is /,\ Tein slit open andspread out. Section of Vein,Valves closed bypressure behind. Outside of Valve o£ Plan of Action o*Distended Vein. Valves. Fig. 48. Showing semi-lunar Valves of Veins. The structure and action of each valve are similar tothose of the aortic, pulmonary, and Eustachian valvespreviously described. 104 ANIMAL PHYSIOLOGY. 212. Evidence of Circulation Obtainable in the LivingBody. (1.) AVheii special poisons or soluble salts, as prussiate or nitrateof potash, are injected into the veins in one part of the system,they can readily be detected in blood drawn from remote veins inthe course of a few seconds only. , (2.) Alcohol and other substances taken into the stomach canbe detected in the blood and in the urine very shortly after itsinjection. (3.) If a vein be wounded, pressure applied between it and theheart will not affect the bleeding; whereas pressure on the remoteside of the wound will immediately arrest it. (4.) On t
Size: 964px × 2591px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookce, bookdecade1870, booksubjectanatomy, booksubjectphysiology
