Blood Flashcards
composition, structure and function, blood typing, disorders, etc.
What is the percent composition of whole blood?
Plasma - 55%
Formed elements - 45%
What is the percent composition of plasma?
Water - 91%
Proteins - 7%
Albumins
Globulins
Fibrinogen
Prothrombin
Other solutes -2%
Ions, nutrients, waste
products, gases, regulatory
substances
What is the percent composition of formed elements?
Erythrocytes - >99%
Platelets - <1%
Leukocytes - <1%
What is the normal volume of blood?
Plasma - 2.6L
Formed elements - 2.4L
Whole blood - 4 to 6L
7% to 9% of total body weight
Describe blood pH.
Blood is alkaline - pH 7.35 to pH 7.45
Acidosis occurs if blood pH decreases toward neutral.
What percent of gases are transported in plasma?
About 1.5% of total oxygen
About 10% of total carbon dioxide
List the white blood cells (leukocytes).
Neutrophils - 65-75%
Lymphocytes - 20-25%
Monocytes - 3-8%
Eosinophils - 2-5%
Basophils - 0.5-1%
What are the blood cell counts of RBCs, WBCs, and platelets?
RBCs - 4.5-5 million/mm3 of blood
WBCs - 5000-10,000/mm3 of blood
Platelets - 300,000/mm3 of blood
Explain hematopoiesis.
The formation of all new blood cells in the myeloid tissue (red bone marrow).
WBCs finish developing in the lymph nodes, thymus, and spleen.
How long to blood cells live?
RBCs - about 4 months
WBCs (granular) - a few days
WBCs (agranular) - over 6 months
Describe the structure of red blood cells.
-Tough, flexible plasma membrane (allowing RBCs to pass through small capillaries)
-Biconcave disc shape (large membrane surface area and reduced spinning as blood flows)
-Absence of nucleus and cytoplasmic organelles (provides more cellular space for hemoglobin; limits life span to about 120 days)
What is the function of RBCs?
Transport of respiratory gases (oxygen and carbon dioxide)
What is a CBC?
Complete blood cell count: battery of laboratory tests used to measure the amounts or levels of many blood constituents.
What is a hematocrit (Hct) test?
Also called a packed cell volume (PCV) test.
Measures the percentage of RBCs in the whole blood.
Low RBCs - anemia
High RBCs - polycythemia
Describe the structure and function of hemoglobin (Hb).
-Quaternary protein made up of four polypeptide chains (2 alpha, 2 beta), each with an oxygen-attracting heme group at the center.
-Iron, folate and B12 needed to manufacture Hb
-transport of respiratory gasses
-role in homeostasis of acid-base balance
What is anemia?
The inability of blood to carry adequate oxygen to tissues due to:
1) inadequate RBC numbers
2) a deficiency of normal hemoglobin
What is hemorrhagic anemia?
Decreased RBC numbers caused by blood loss (hemorrhage).
What is aplastic anemia?
Decreased RBC numbers caused by destruction of blood-forming elements in bone marrow.
What is pernicious anemia?
Lack of intrinsic factor in stomach reduces availability of vitamin B12 needed for RBC production.
What is sickle cell anemia?
Inherited defective gene or genes produce an abnormal type of hemoglobin that is less able to carry oxygen and which often forms clumps of RBCs that block blood vessels.
What is an antigen?
Substance than can activate immune system.
What is an antibody?
Substance made by the body in response to stimulation by an antigen.
What are the ABO blood types?
Type A blood - type A self-antigens in RBCs; anti-B type antibodies in plasma
Type B blood - type B self-antigens in RBCs; anti-A type antibodies in plasma
Type AB blood - type A and type B self-antigens in RBCs; no anti-A or anti-B antibodies in plasma
Type O blood - no type A or type B self antigens in RBCs; both anti-A and anti-B antibodies in plasma
What is the Rh system of blood typing?
Rh positive blood - Rh factor antigen present in RBCs
Rh negative blood - no Rh factor present in RBCs
What is Erythroblastosis Fetalis?
May occur when Rh-negative mother carries a second Rh-positive fetus; caused by mother’s Rh antibodies reacting with the fetus’s Rh-positive cells.
What is the universal donor blood?
Type O-
What is the universal recipient blood?
Type AB+
What are the two types of WBCs?
Granulocytes - possess granules that stain.
Agranulocytes - absence of stained granules.
What is Leukopenia?
Abnormally low WBC count.
-occurs infrequently
-may occur with malfunction of blood-forming tissues or diseases affecting immune system (such as AIDS)
What is Leukocytosis?
Abnormally high WBC count
-frequent finding it bacterial infections
-classic sign in blood cancers (leukemia)
What is a Differential WBC count?
Component test in CBC; measures proportions of each type of WBC in blood sample.
What are Neutrophils?
-granulocyte
-most numerous type of phagocyte
-numbers increase during bacterial infections
What are Eosinophils?
-granulocyte
-weak phagocyte
-active against parasites and parasitic worms
-involved in allergic reactions
What are Basophils?
-granulocytes
-related to mast cells in tissue spaces
-secrete histamine (promotes inflammation)
-secrete heparin (an anticoagulant)
What are Monocytes?
-agranulocyte
-largest leukocyte
-aggressive phagocyte (capable of engulfing larger bacteria and cancer cells)
-develop into much larger cells called macrophages after leaving blood to enter tissue spaces
What are Lymphocytes?
-agranulocyte
-B lymphocytes (B cells) involved in immunity against disease by secretion of antibodies
-T lymphocytes (T cells) involved in direct attack on bacteria or cancer cells (not antibody production)
What are platelets?
-Also called thrombocytes
-Tiny cell fragments filled with clot-triggering chemical
-play an essential role in blood clotting
Describe the clotting process.
1) vasoconstriction of blood vessels
2) damage releases clotting factors that react with plasma factors to create prothrombin activator
3) platelets adhere to the break and form a “platelet plug”
4) prothrombin activator and calcium convert prothrombin to thrombin
5) thrombin reacts with fibrinogen to form fibrin
6) fibrin threads form a tangle to trap RBCs (and other formed elements) to produce a blood clot
What is a thrombus?
A stationary blood clot
What is an embolis?
A circulating blood clot
What is tissue plasminogen activator (tPA)?
A drug used to dissolve already formed blood clots
