I. Composition & Function of Blood. A. Components 1. Plasma - Connective tissue in which formed elements are suspended in a fluid matrix called plasma Formed elements: 1. Erythrocytes: red blood cell 2. Leukocytes: white blood cells
1. 90% water
2. 100+ dissolved solutes including nutrients, gases, hormones, wastes, ions, proteins
3. Plasma proteins:
a. Albumins: 60%; carrier molecule, buffer, plasma osmotic pressure with Na+
b. Fibrinogen: clotting protein
c. Globulins: antibodies
Function: blood clotting, defense, hormones, enzymes, carriers for different substances.
2. Most survive in the bloodstream for only a few days
3. Most do not divide but are renewed in the bone marrow
Stimulated by Erythropoietin
1 oz. of new blood with 100 billion
new cells per day
Red cell-producing marrow cells are
hematopoietic stem cells
In adults, only the spine, ribs, pelvis,
bodies of vertebrae, portions of skull,
and proximal ends of long bones
produce blood cells.
Formed in lymphoid tissue(lymph nodes, tonsils, spleen, thymus) and then transported in blood to different parts of the body.
Attracted to certain chemicals released by damaged cells or other leukocytes and move by amoeboid motion
Provide a rapid and potent defense against infection
Are the only formed elements of blood that are complete cells
5 types of mature white blood cells (leukocytes):
Renegade leukocytes that remain unspecialized and divide out of control, impairing normal bone-marrow function
a. Function: contain chemicals that act in blood clotting
b. Cell fragments split off a parent cell - megakaryocytes.
Thrombopoietin: a glycoprotein that regulates growth and maturation of megakaryocytes
1. Blood is transformed from liquid to a gel
2. Prothrombin converts a plasma protein called prothrombin > thrombin, an enzyme
3. Thrombin catalyzes fibrinogen present in the plasma to a fibrin mesh that traps blood cells and seals the hole until the vessel can be repaired
4. Clot formation complete in 3-6 minutesCLOTTING
1. RBCs have antigens (agglutinogens) on surface that identify
2. RBC antigens promote agglutination so are called agglutinogens.
If the baby's Rh positive blood enters a mother who is Rh Negative, then her immune system sees the cells as 'incompatible' or 'foreign' and will subsequently produce anti-rhesus antibodies to try to destroy them for her own self-protection.
If she has another pregnancy where the baby is Rh positive, then these antibodies that have formed will pass into the baby's bloodstream via the placenta and attack the red blood cells of the baby.
Once these naturally created anti-rhesus antibodies are present in the mother's bloodstream, they will remain for life.
Give Rho Gam that masks the agglutinin component so it does not recognize its presence and activation will not occur.