Elements of animal physiology, chiefly human . ybe felt by the hand striking against the walls of thechest during the beating of the heart. (See figs. 2, 3,and 41 and 43.) The heart is about 5 inches long, 3^ inches broad, and21 inches thick. Its average weight in the male is tento twelve ounces, in the female eight to ten forms about y|-g- of the weight of the whole body ofthe male, and yjg- of that of the female. 183. The Heart, which is a kind of force-pump, is theprincipal organ of circulation. From it the bloodacquires the j^ropit^siye force by Avhich«it performs thevarious move
Elements of animal physiology, chiefly human . ybe felt by the hand striking against the walls of thechest during the beating of the heart. (See figs. 2, 3,and 41 and 43.) The heart is about 5 inches long, 3^ inches broad, and21 inches thick. Its average weight in the male is tento twelve ounces, in the female eight to ten forms about y|-g- of the weight of the whole body ofthe male, and yjg- of that of the female. 183. The Heart, which is a kind of force-pump, is theprincipal organ of circulation. From it the bloodacquires the j^ropit^siye force by Avhich«it performs thevarious movements just described. The heart is a hollow, conical, fleshy bag, about thesize of a mans fist. It consists of involuntary butstriated muscular fibre. The heart is divided by septaand valves into four cavities, which have no direct com-munication with each other; that is, the blood on one THE HEAR*. §9 side of tlie lieait cannot pass over to tlie cavities on theother side of the heart, without passing through the blood-vessels in the «r, Top of 5, Left Artery- c, Left Jngnlar Vein, (f, Arnh of Aorta,c, Pnlmouary Arteiy. /, Broiialii and Blood-vessels, g. Left Lung, h,Right Ventricle, i, KiuUtA«ricle. j. Third Lobe of Right Lwicr. k, Siiperior Vena Cava. I, Right Subclaviau Vein,m, Right Jugular Veiu. n, Right Carotid Artery. The heart is completely enveloped in a closed sac ofserous membrane, termed the idericardium. The human heart is usually described as containingtwo distinct sides (a right and a left), separated byji fleshy wall, termed the median sejitum of the the heart of man, of birds, and of the mammaliamay be said to consist of two complete hearts—a rightand a left heart—each heart corresponding to the singlecomplete heart of a fish; the human heart thus forminga double heart, and the circulatory movemeiit set up byit a double circulation, termed respectively the greater 90 ANIMAL JPHYSIOLOGY. or systemic circulation,
Size: 1607px × 1554px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookce, bookdecade1870, booksubjectanatomy, booksubjectphysiology
