Lessons and experiments on scientific hygiene and temperance for elementary schoolchildren / by Helen Coomber.
- Coomber, Helen.
- Date:
- 1914
Licence: In copyright
Credit: Lessons and experiments on scientific hygiene and temperance for elementary schoolchildren / by Helen Coomber. Source: Wellcome Collection.
Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.
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![SKCT. (2). What will il liciiiadc of inyour ;irm'^—Muscle,and runjiiiig iu and iinio)!,^ iJiis iiuisclc are the bluLsh-red blood-veHsek Can i show all the braiielies ?—No, because some will, of course, fto back dee])er into the arm, some come uj) into a higher layer! ' I can only show some of those which run along my slice. Lift- ing- this slice you see this slip (3), which sliows a layer just above the bone; here I have marked nioi'e blood-vessels, but this time in brighter red, for if you cut down to this layer you would find the blood scarlet and not the bluisli-red coloui- you see it in the vessels near the surface. Layer 4 shows bones them- selves. If you went on and lifted out the bone 3'ou would find more vessels with scarlet blood furthei- in, and vessels with Fig. 46. bluish-red blood as you pass out, till you reach the skin of the outer side of your arm. 1 have only shown a few of the main big vessels, every one has many branches, each branching again into smaller and smaller branches like this. Imagine a net- work of the finest lace with all its threads, made of hollow tubes; if it were 25 times smaller, those you could see woiUd be like these finest branches. These again collect up into larger branches. How do you know that there must be far more branches tlian I can draw, that, iu fact, there is not a point under yom' skin where there is not some one of these branches ? Prick yourself anywhere and what happens ? So fine branckes are nearer together than a pin-point. Examine rabbit's leg used in earlier lesson on muscle. Note again the large blood-vessel running down with the nerve](https://iiif.wellcomecollection.org/image/b21508513_0144.jp2/full/800%2C/0/default.jpg)
