Chapter 11 BLOOD Primary transportation fluid of the body Chapter 11 BLOOD Primary transportation fluid of the body. Serves the circulatory and lymphatic systems.

8% of adult body weight. Blood is a TISSUE

BLOOD is a fluid tissue with dissolved chemicals and lots of cells floating in it. 2 COMPONENTS 1. Blood Plasma- the liquid part 2. Formed Elements- cells and cell fragments.

BLOOD PLASMA The liquid component of BLOOD, in which the FORMED ELEMENTS are suspended. Makes up about 55% of total blood volume Blood Proteins COMPOSITION OF PLASMA ALBUMINS-thicken the blood GLOBULINS- gamma globulins are the antibodies. Alpha and beta globulins transport other substances like hormones, lipids etc. FIBRINOGEN- involved in blood clotting. PROTHROMBIN- AKA Factor II, a clotting factor 91% WATER 7% PROTEINS------------ 2% OTHER SOLUTES-ie. salts, hormones, gases, cellular waste products etc. Albumins 57%, Globulins- 38%, fibrinogen – 4%, is converted to thrombin in the presence of thromboplastin and calcium ion during blood clotting. Also called factor II.

BLOOD SERUM Plasma minus clotting factors (fibrinogen and prothrombin)

FORMED ELEMENTS- 3 MAIN TYPES 1. ERYTHROCYTES- red blood cells. RBCs- 4.5-5 million per mm3. 2. LEUKOCYTES- white blood cells WBCs- 5000-10 000 per mm3 …many types …more on that later 3. THROMBOCYTES – Platelets- 300 000 per mm3. 1mm3 = approximately 1 drop of blood.

HEMOPOIESIS -Blood cell formation occurs in: Myeloid tissues- AKA red bone marrow found mainly in the sternum, ribs, hipbones in adults. Red bone marrow forms all types of blood cells except some lymphocytes and monocytes. Lymphatic tissues- lymph nodes, thymus and spleen forms some lymphocytes and monocytes not formed in the bone marrow. Both are connective tissues. A few million RBCs are made each second HEMOPOIESIS

ERYTHROCYTES RED BLOOD CELLS- A normal human adult has approximately 3 X 1013 (thirty trillion) RBCs Structure: Bi-concave disc NO NUCLEUS in mature RBCs Function: Transports O2 and CO2 The total surface area of all rbcs in the body is larger than a football field. Avg. life span- 120 days http://www.pbrc.hawaii.edu/microangela/rbc.htm

Hemoglobin + Oxygen  oxyhemoglobin Carries O2 to all body cells Hemoglobin + CO2 carbaminoglobin Only a small amount of CO2 is carried by hemoglobin in the blood. most CO2 is carried in the plasma as carbonic acid.

ANEMIA The inability of blood to carry a ANEMIA The inability of blood to carry a sufficient oxygen supply to cells causing HYPOXIA (low oxygen). Anemia can be caused by: 1. Inadequate RBC numbers 2. Hemoglobin deficiency in RBCs.

IRON DEFICIENCY ANEMIA LACK of IRON in the diet causes a lack of hemoglobin in the RBCs. Most common form of anemia. APLASTIC ANEMIA Failure of the bone marrow to function properly (damage to blood forming elements in the bone marrow). Causes may include excessive radiation exposure, certain cancer drug therapies, some chemical poisons. Hemorrhagic Anemia Caused by a decrease in RBC numbers due to hemorrage.

PERNICIOUS ANEMIA Caused by a lack of vitamin B12 or of intrinsic factor, (a protein that is essential for B12 absorption), which are essential for RBC maturation. Sickle-Cell Anemia Mutation in the hemoglobin gene. Defect caused by the insertion of ONE incorrect amino acid. Causes hemoglobin to form crystals in low O2. Crystals can deform the cell and rupture membranes. www.defiers.com/sc.jpg

POLYCYTHEMIA Excess production of RBC’s POLYCYTHEMIA Excess production of RBC’s. Blood thickens and is unable to flow properly.

HEMATOCRIT Measure of the percentage of red blood cells present in a whole blood sample (and the size of the RBCs). A sample is spun down and the contents layer. Top layer- plasma Buffy Coat- WBCs and platelets Bottom layer- RBCs

LEUKOCYTES WHITE BLOOD CELLS 2 broad categories GRANULAR and NONGRANULAR

Granular leukocytes- (granulocytes) have granules in the cytoplasm; most often secretory vessicles that can destroy ingested bacteria. 1. Neutrophils 2. Eosinophils 3. Basophils Non-granular leukocytes- (agranulocytes) 1. Lymphocytes 2. Monocytes

White Blood Cells defend the body against both infectious disease and foreign materials. All leukocytes are produced and derived from a multipotent cell (have the potential to give rise to cells from multiple, but a limited number of lineages) in the bone marrow known as a hematopoietic stem cell.

Granular Leukocytes- 3 types 1. Neutrophils- most numerous leukocytes, Granular Leukocytes- 3 types 1. Neutrophils- most numerous leukocytes, 60% of the WBCs. PHAGOCYTES (engulf microbes and digest them) 2. Eosinophils- 1-3% of WBCs. Helps control allergic reactions and parasitic infections (ie. tapeworm, hookworm). Can also function as phagocytes. 3. Basophils- >1% of WBCs Involved in allergic and inflammatory response. Contain HEPARIN, an anti-clotting chemical.

Agranularocytes – 2 types 1 Agranularocytes – 2 types 1. LYMPHOCYTES -30% of WBC s Responsible for Immune System Response 2 TYPES B-lymphocytes- (B-cells) Humoral immune response. Produce antibodies that attack bacteria and toxins. ("B", comes from the bursa of Fabricius in birds, where they mature). In mammals, immature B cells are formed in the bone marrow and mature and differentiate in the spleen. T-lymphocytes- (T-cells) attack body cells when they have been taken over by viruses or have become cancerous. "T" stands for thymus, where their final stage of development occurs. involves substances found in the humours, or body fluids.

2. MONOCYTES-Develop into macrophages- phagocytes that consume bacteria, dead cells, and waste materials

White blood cell disorders- LEUKOPENIA- Abnormally low white blood cell count. Viral infections, chemotherapy, cirrhosis depress WBC count LEUKOCYTOSIS - Elevated white blood cell count. May indicate bacterial infection, leukemia (blood cancer)

PLATELETS and BLOOD CLOTTING

PLATELETS – (thrombocytes) The third main type of formed elements PLATELETS – (thrombocytes) The third main type of formed elements. Cell Fragments of membrane enclosed cytoplasm that are produced in the bone marrow from a megakaryocyte, which sheds the platelets into circulation. NO NUCLEUS in a platelet.

Platelets function in two ways: 1st-they physically plug breaks in blood vessels (temporary) 2nd-they release chemicals that promote clotting (more permanent).

Within 2 seconds of an injury: a vascular spasm occurs; blood flow is slowed; platelets contact collagen fibers in the walls of the vessel and become sticky, forming a platelet plug. After 20 seconds a more permanent clot begins to form.

HOW COAGULATION (blood clotting) HAPPENS 1. Injury occurs. 2 HOW COAGULATION (blood clotting) HAPPENS 1. Injury occurs. 2. A series of reactions involving clotting factors form PROTHROMBIN ACTIVATOR

3. Prothrombin activator converts prothrombin ( a globulin) to THROMBIN. Calcium must be present for this to occur. Prothrombin is manufactured in liver and Vitamin K must be present for its formation.

THROMBIN reacts with the plasma protein FIBRINOGEN which polymerizes forming FIBRIN.

FIBRIN threads trap blood cells, platelets and plasma FIBRIN threads trap blood cells, platelets and plasma. How does blood clot

HARMFUL CLOTTING Thrombus- a clot that forms within a blood vessel causing thrombosis. Embolus- a clot that breaks away and moves through the circulation.

BLOOD GROUPS ANTIGENS-(agglutinogens) proteins on the surface of red blood cells. ANTIBODIES- (agglutinins) present in blood plasma.

Agglutination “to glue to” Antibodies react with antigens and “clump” the cells together. Cells may also lyse, causing the release of hemoglobin into circulation.

ABO Blood Groups Blood Type. Antigen A. A only. B. B only. AB ABO Blood Groups Blood Type Antigen A A only B B only AB both A & B O neither A or B

Antibodies develop after birth in the plasma of the blood Antibodies develop after birth in the plasma of the blood. You have the antibodies for the antigens that are NOT present

You have blood Type A: you have Antigen A on the RBC membrane and anti-b antibodies in your blood plasma.

Blood Antigen Antibody Type_______ cell membrane___________plasma_____ A A Anti-b___ B B Anti-a___ AB A&B neither Anti-a ____________________nor Anti-b__ O none both anti-a and anti-b

UNIVERSAL DONOR Type O Since they do not have A or B antigens, no agglutination (clumping) can occur.

UNIVERSAL RECIPIENT Type AB Since they lack A and B antibodies they do not react badly to any ABO blood type.

Average frequencies of ABO blood groups in US. 45% Type O 40% Average frequencies of ABO blood groups in US. 45% Type O 40% Type A 11% Type B 4% Type AB

Rh SYSTEM First discovered in the rhesus monkey Rh SYSTEM First discovered in the rhesus monkey. C, D, and E genes code for the Rh antigens on the red blood cell membrane

Rh + Rh antigens are present Rh – Rh antigens are not present

Normally the plasma DOES NOT contain Rh antibodies Normally the plasma DOES NOT contain Rh antibodies. Rh- individuals that receive Rh+ blood WILL DEVELOP antibodies which remain in the blood

ERYTHROBLASTOSIS FETALIS Rh- mother and Rh+ father Rh+ baby Baby’s blood may mix with mothers causing the mother to develop antibodies against Rh+ blood.

Next Rh+ baby: Antibodies can cross the placenta and cause the hemolysis of the baby’s red blood cells. Hemolysis may cause the release of hemoglobin which can severely damage organs.

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