An elementary physiology and hygiene for use in upper grammar grades . liquid part passesthrough, the corpuscles remaining in the blood —A four-track railroad usually has twotracks for the trains, say from Chicago, and two for the trains going toChicago. Let us saythat the two tracksfrom the railroadcenter represent thearteries which takethe blood away fromthe heart. After itsjourney throughsmaller arteries orbranch roads, andthrough the capil-Showing their method of branching. The laY{es or switchesfigure on the right shows capillaries inthe skin ; on the left, capillaries in th
An elementary physiology and hygiene for use in upper grammar grades . liquid part passesthrough, the corpuscles remaining in the blood —A four-track railroad usually has twotracks for the trains, say from Chicago, and two for the trains going toChicago. Let us saythat the two tracksfrom the railroadcenter represent thearteries which takethe blood away fromthe heart. After itsjourney throughsmaller arteries orbranch roads, andthrough the capil-Showing their method of branching. The laY{es or switchesfigure on the right shows capillaries inthe skin ; on the left, capillaries in the where it leaves the muscles- food, the blood is ready to go back to the heart on the return tracks. The little capillary branches combine into largertubes or blood vessels called veins, which carry theblood back to the heart. The veins in turn combine,and the nearer they get to the heart the larger and thefewer in number they become. Finally they unite intotwo large veins, which pour all the blood back into theheart. Figure 22 B shows the connection of the heart. Eig. 25. — Capillaeies. CIRCULATION 89 Polm> Grcuhtii m/ktion with these veins. With the next beat after the bloodhas been poured into the heart from the veins, it ispumped out again, and sent once more on its circuit tothe lungs and around thebody. The general arrange-ment of the heart, arteries,capillaries, and veins may beunderstood from Figure 26. The whole process of cir-culation, as it is called, islike what would happen ifall the water that flows fromour water faucets, and, afterbeing used, is thrown intoour sinks, were carried backto the reservoirs, there tobe thoroughly purified, andsent out once more to thevarious houses. All of the arteries, exceptthose going to the lungs, carry pure blood, while the Fig. 26. —A Diagram showingveins, except those comingfrom the lungs, carry im-pure blood. The pure blood becomes impure as it takes up waste material in thecapillaries, as explained in a later chapter
Size: 1596px × 1565px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectphysiology, bookyear1
