A reference handbook of the medical sciences, embracing the entire range of scientific and practical medicine and allied science . lood circulates includes the heart, arteries, capil-laries, and veins. The first of these is essentially amuscular force pump whose rhythmical strokes atthe rate of about seventy-two per minute drive theblood through the vessels in a constant directionwith a considerable velocity. Before taking upthe action of the central pump, it will be convenientto note the general features of this blood current. Its study is essentially a physical problem in hydro-dynamics whos
A reference handbook of the medical sciences, embracing the entire range of scientific and practical medicine and allied science . lood circulates includes the heart, arteries, capil-laries, and veins. The first of these is essentially amuscular force pump whose rhythmical strokes atthe rate of about seventy-two per minute drive theblood through the vessels in a constant directionwith a considerable velocity. Before taking upthe action of the central pump, it will be convenientto note the general features of this blood current. Its study is essentially a physical problem in hydro-dynamics whose complete theoretical treatmentis rendered practically impossible by the complexarrangement and mode of branching of the vessels,by the constant change in the physical propertiesof their walls along their length, and by the continualinteraction of their physiological activities. Anaccount of the mechanics of the flow in the vesselsmust be based mainly on experimental data, and thefundamental laws of hydrodynamics based on theflow of liquids in simple models are introducedmerely to assist in the interpretation of these Fig. 70S.— Diagram Illustrating the Flow of Liquids in aHorizontal Rigid Tube of Uniform Caliber, when Connected witha Reservoir. (From Rollett.) The Flow op Liquids in Rigid and El.\.stic Tubes.—Torricellis theorem states that when water escapesfrom an aperture in the side of a reservoir filled to aconstant level, the velocity of outflow theoreticallyis given by the formula v = \/2gH in which g equalsthe acceleration of falling bodies produced by gravityand H equals the height of the column of liquid abovethe aperture. The actual velocity is obtained bydividing the amount which flows out in a unit of timeby the cross-section of the aperture, and experimentshows that this is less than the theoretical value. A 133 Blood, Cireiilatlon of REFERENXE HAXDBOOK OF THE MEDICAL SCIENCES part of the energy of position represented by the col-umn of liquid H is lo
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Keywords: ., bookauthorbuckalbe, bookcentury1900, bookdecade1910, bookyear1913
