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.
158/192 page 134
![where?—Tlie red. :iiul t-lie lilue vessels joined; but they (Jo soinethiiifj,' else before tliey join. Wiiat '{ Do they go on as single tubes ?—No, they break up into brandies, and these into smaller and smaller branches, just as 1 showed you in the ])a]Hn' arm model; and then the (inest bran(;hes of the set coming i'rom the heart run into the finest branches of those going back to the heart like this. So then it is one big S3'stem of tubes with no break. (There are really two breaks, at tlie neck and hi the spleen, but this is imiiecessary for the children.) The branches when they join are far too tiny to see, finer than tlie finest hau- you can imagine, but the blood can pass along them all right. Where do you find these networks of fijie branches ?— Fig. 53. Spread over nearly all the organs, over the digestive tube, arms, legs, brain, everywhere. These fine branches have very thin walls. Why ?—So that the food in the blood can pass tlu'ough to the protoplasm and nourish the arm, or leg, or brain cell. So now we must do something further to our heart box model. What ?—Frazzle out the wool threads to represent branches, and bring the finest ends of both together. We can't connect them as the blood-vessels connect, because we can't manage to jobi the wool ends together; we can only lay them on one another, and we wUl stick them together with labels, and write on one label leg muscle, and another digestive tube, ' etc. What do we call blood-vessels going from the heart ?—4 )-?erzes ; and blood-vessels going to it we call—what %—Veins. Show me the artery on your model, and two veins. Where will one branch of the artery go ?—To the digestive tube. What does it do there ?—Breaks up into finer and finer branches. U hat do these run into ?—Fine branches of a vein, which finally run](https://iiif.wellcomecollection.org/image/b21508513_0158.jp2/full/800%2C/0/default.jpg)
