Definition and causes
The blood is composed of liquid blodvæske calledblood plasma(about 55%) andblood(about 45%). Hælder Monday blood in a test tube, the cells will sink and plasma will break off into the top half of the glass.
Blood plasma is a straw-clear liquid, which contains different nutrients, hormones, antibodies, coagulation factors (størkningsproteiner) and salts. 95% of blood plasma is water. Lets Monday glass stand for a while, the cells in the bottom clot. In this process used some størkningsstoffer from blodplasmaet. Blood plasma without these substances called serum.
Blodcellerne can be divided into the following:
- Platelets (platelets) formed in bone marrow , And is the smallest cells in the blood, where they live around. 10 days. Trombocytters function is to stop a hemorrhage in, for example. a blood vessel or a wound on your skin.
- The white blood cells (leukocytes) formed also in the bone marrow and is an important part of the body's immune system. They participate in a betændelsesreaktion against infections by bacteria, viruses, parasites and fungi. The white blood cells are larger and can be found in far fewer numbers than the red blood cells. Leukocytterne found in most of the lymphatic system disorders and other tissues, and to a lesser extent in the blood. They can be divided into the following subgroups:
The basofile granulocytes.
- B lymphocytes.
(when they come out of the bloodstream develop into macrophages).
- The red blood cells (erythrocytes) formed in the bone marrow, forming 2 million per second, while there are 2 million to land in the body. Of all the body's cells, there are as many red cells, these represent around. 45%, and their life is about. 120 days. The red blood cells containing hemoglobin, which can bind oxygen. The red cells carry oxygen from the lungs to the tissues where it is made. Then the cells carrying the carbon dioxide from the tissues to the lungs, where it udåndes.