Search -
A Course of Elementary Practical Physiology
A Course of Elementary Practical Physiology Author:Michael Foster Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: LESSON III. COAGULATION OF BLOOD. 1. Watch carefully the natural coagulation of freshly shed blood. This will be obtained by the demonstrator. Observe—a. The... more » natural perfectly fluid stage. b. The viscid stage, c. The jelly stage, d. The appearance of the first drops of serum, e. The continued contraction of the fibrin, resulting in the ordinary clot and serum. 2. Whip a small quantity of freshly shed blood. Wash with water the clot so obtained. Note the quantity and observe the following general characters of fibrin. a. It appears under the microscope as a fine felt- work of granular fibrils. 6. It is elastic. c. It is insoluble in water and in normal saline solution. d. It swells up and becomes transparent when treated with dilute hydrochloric acid; but it is not dissolved at ordinary temperatures. Leave in a test-tube a little of the whipped blood for twenty-four hours, and satisfy yourself that it undergoes no further coagulation. 3. Examine the plasma of horse's blood kept, by means of cold, from coagulating. (Hdb. p. 167.) a. Transfer with a pipette 2 or 3 cc. of the plasma into a small test-tube. Observe the coagulation and compare it with that of § 1. Avoid shaking. Probably the fibrin will adhere so strongly to the sides of the tube that little contraction will take place. On being freed from the glass it will contract. b. Dilute 1 cc. of the plasma with 50 cc. of distilled water or normal saline solution. Carefully avoid shaking and leave it till the next day. Observe the fine delicate fibrils of fibrin which are formed. c. Examine, without washing, the characters of the fibrin of a and b. They are best fitted to shew the microscopical characters; white corpuscles will be found entangled among the fibrils. 4. Examine the plasma of b...« less