Ch. 17 - Blood

Hemophilia

- Bleeding disorder: not enough clotting - Inherited bleeding disorder - Genetic deficiency in clotting factor production - Causes prolonged and life threatening bleeding - Treatment: blood transfusion(temporary

Thrombocytopenia

- Bleeding disorder: not enough clotting - Low/deficient platelet number -Treatment: blood transfusion(temporary)

Thrombocytes/Platelets

- Cytoplasmic fragments of cells produced by megakaryocytes("big nucleus cell"); not cells - Mediate hemostasis: stoppage of bleeding - Only live 50 to 100 days - Thrombopoiesis stimulated by thrombopoietin(hormone regulating formation of platelets)

Leukemia

- Leukocyte disorder; overproduction of abnormal WBC - Cancer of the blood: WBCs are overproduced by stem cells which proliferate out of control - More serious acute forms usually affect children; Chronic occurs more in eldery - Deadly because cells proliferate at the expense of raw materials for other blood cells and non-functional or dysfunctional WBCs may be produced, hindering the bodies ability to fight infection - Symptoms: fever, weight loss, bone pain - Common death: internal hemorrhage, overwhelming infections(due to abnormal overproduction)

Coagulation

- Multi step cascade of plasma proteins - Last, most effective step of hemostasis - Major event catalyzed by thrombin where fibrinogen(soluble) cross links with fibrin(insoluble, "molecular glue") and creates a net to catch blood leaking from damaged vessel

Agglutination

- Recipient agglutinins will "attack" the donor's RBCs, forming clumps of RBCs that will clog blood vessels - Antigens are proteins on cell surface which tell other cells whether its you or foreign cell

Thrombus

- Thromboembolic disorder: undesirable clotting, blocks blood flow - A clot which develops and persists in clogging a blood vesself Ex. coronary thrombosis= heart attack - Anticoagulant drugs= prevent undesirable clotting by blocking various parts of the clotting cascade Ex. Aspirin, Heparin, Warfarin(Coumadin)

Embolus

- Thromboembolic disorder: undesirable clotting, blocks blood flow - A clot which floats in blood stream and can become wedged to block a blood vessel, an embolism Ex. pulmonary, cerebral embolism= stroke - Anticoagulant drugs= prevent undesirable clotting by blocking various parts of the clotting cascade Ex. Aspirin, Heparin, Warfarin(Coumadin)

Life Cycle of Erythrocytes/RBCs

1. Erythropoisis: RBCs formed in red bone marrow. Iron(heme) and amino acids(globin) are required to produce RBC along with folic acid or vitamin B12 for DNA synthesis in mitotic cells 2. "Ghost-like" RBCs travel bloodstream transporting O2 3. After death(120 days): macrophages engulf and breakdown hemoglobin in the spleen and recycle raw materials. Globin degraded into amino acids, which are raw materials for protein synthesis. Heme splits and iron is recycled in the liver and the pigment converted to bilirubin

Regulation of RBC Production

1. Humoral stimulus: Hypoxia= low O2 levels getting to tissues, leads to body trying to make more RBC; due to decreased RBC count, decreased amount of hemoglobin, decreased availability of O2 2. Detected by kidney and liver, which then releases erythropoietin, which is a glycoprotein hormone that stimulates the formation of erythrocytes 3. Erythropoietin(EPO) stimulates red bone marrow to make more RBC 4. Enhanced erythropoiesis increases RBC count 5. RBCs increase O2 carrying ability of blood during the 120 days - homeostasis= normal blood oxygen levels - EPO produced in kidney and liver - Erythropoiesis in red bone marrow - Negative feedback

Composition of Whole Blood

1. Plasma: 55%; fluid portion dissolves solutes; 90% water 2. Formed Elements: Buffy Coat: 1%; white-ish interface; Leukocytes(WBCs) and Thrombocytes(platelets) Erythrocytes: 45%; hematocrit; RBCs

What are the main elements of blood, as a connective tissue?

Blood is a connective tissue just like bone, connective tissue proper(fat), and cartilage. The common origin develops from mesenchyme. Its structural elements is that there are living cells which are the white blood cells and has a extracellular matrix which is the plasma.

Sickle-Cell Anemia

Causes: by abnormal hemoglobin(HbS); a single nucleotide change in DNA sequence causes 1 amino acide change in a 146 amino acid chain forming beta globin; a change in structure changes function where RBC is a crescent shape under low O2 conditions; sickled cells rupture and die easily(hemolytic) where the lifespan is 10-12 days vs 120 days Symptoms: impaired O2, delivery to tissues(Hypoxia > Neurosis > tissue death) Treatments: blood transfusions, fluids(to keep RBCs hydrated), fetal hemoglobin(can bind oxygen with greater efficiency than adults) Lethal Trait Continue: carrying two copies of mutation= sickle-cell anemia=deadly; carrying one copy of mutation= sickle-cell trait; occurs in the "malaria-belt"

Erythropoiesis

Erythropoiesis is the erythrocyte production. - Begins when a hematopoietic stem cell descendant called a myeloid stem cell transforms into a proerythroblast - Proerythroblasts give rise to basophilic erythroblasts, which produce huge numbers of ribosomes - Hemoglobin is syntehsized and iron accumulates as the basophilic erythroblast transforms into a polychromatic erythroblast and then an orthochromatic erythroblast - Color of cell cytoplasm changes as the blue ribosomes become masked by the pink color of hemoglovin - When an orthochromatic erythroblast has accumulated almost all of its hemoglobin, it ejects most of its organelles - Nucleus degenerates and allows the cell to collapse inward and assumes the biconcave shape - Results are the reticulocyte which is a young erythrocyte

Formed Elements

Formed elements are "cellular components", though not all are true cells. 1. Erythrocytes: red blood cells; have no nuclei or organelles; born in bone marrow; have hemoglobin which transport oxygen 2. Thrombocytes: platelets; cell fragments; stimulate clotting 3. Leukocytes: white blood cells; complete cell; fight infection

5 Different Types of Leukocytes

Granulocytes: Neutrophil= "eat bacteria" Eisonophil= "eat worms"; complex role in allergy and asthma Basophil= release histamines of inflammation; contain heparin, an anticoagulant Agrunolocytes: Lymphocyte= T-cells and B-cells; immune cell to attack antibodies Monocyte= macrophages

Hematopoiesis

Hematopoiesis is the formation of blood cells. This process occurs in the red bone marrow, found in epiphysis in long bone, spongy bone of flat bones.

Hemoglobin

Hemoglobin is the protein carrier of O2 and sometimes CO2. They find and carry oxygen. Hemoglobin is made up of heme, red iron(Fe) containing pigment which binds O2 and globin, 4 polypeptides chains which each contains a heme group. This means that 4 molecules of O2 can bind to 2 hemoglobin. - Fe helps bind the oxygen - 4 globins binds CO2, 4 hemes binds O2 - More oxygen more rich(bright red), less oxygen is poor(dark red)

Anemia

Hemorrhagic Anemia: acute or chronic blood loss, bleeding out Iron Insufficiency Anemia: not enough iron in the diet, not enough RBC are produced Pernicious Anemia: not enough B12, not enough RBC are produced Renal Anemia: lack of, or low erythropoietin(EPO), not enough RBC are produced Aplastic Anemia: destruction of red bone marrow, not enough RBC are produced Hemolytic Anemia: too many RBC destroyed; ex. hemoglobin abnormality in sickle-cell anemia

Jaundice

Jaundice is the yellowing of the skin, mucous membranes, or eyes and is caused by a buildup of pigment bilirubin in the body. If the liver is not keeping up with degrading of bilirubin this occurs. The breakdown of bilirubin is in the liver which makes our poop brown and in the kidneys which makes our pee yellow. Treatment: sun exposure and UV light

Leukocytes/WBC

Leukocytes are white blood cells and is the only formed element that are true cells. Their main function is to fight infection and defend body against diseases. There are 5 different leukocytes; the granulocytes: neutrophil, eiosophil, and basophil. the agranulocytes: lymphocyte and monocyte. Leukopoeisis is stimulated by chemical messengers such as colony stimulating factor(CSF) and interleukins

Oxygenation of Hemoglobin

Oxyhemoglobin: when hemoglobin is bound to O2(ex. in the arteries) it is ruby red in color Deoxyhemoglobin: when hemoglobin is not bound to O2(ex. in the veins) it is dark red in color. Carbaminohemoglobin: when hemoglobin is bount to CO2(ex. in the veins); Oxygen binds to heme; Carbon dioxide binds to(amino acids) globin

Blood Plasma

Plasma is a "non-living fluid matrix" that has 90% of water and 9% solutes. The solutes are electrolytes, proteins, respiratory gases, nitrogenous wastes, nutrients, and hormones. Solutes: - Electrolytes= charged ions produce electricity; Help to maintain plasma osmotic pressure and normal blood pH; Ex. Na, K,Ca - Proteins= all contribute to osmotic pressure and maintain water balance in blood and tissues and other functions such as transport and enzymatic; Ex. Albumin=serves as blood taxi to transport lipid-soluble hormones, Fibrinogen=forms fibrin threads of blood clot - Respiratory Gases= Ex. O2, CO2; Oxygen mostly bound to hemoglobin inside RBCs; Carbon dioxide transported dissolved as bicarbonate ion - Nitrogenous Waste= Products of cellular metabolism like the urea; Ex. uric acid, creatinine, ammonium salts - Nutrients= materials absorbed from digestive tract and transported for use throughout body; Ex. amino acids, glucose, simple carbohydrates, fatty acids, glycerol, triglycerides, cholesterol, vitamins - Hormones= steroid and thyroid hormones carried by plasma proteins

Hemostasis

Stoppage of bleeding by forming a blood clot 1. Vascular spasm: smooth muscle contracts causing vasoconstriction 2. Platelet plug formation: injuring to lining of vessel exposes collagen fibers, platelets adhere. Platelets release chemicals that make nearby platelets sticky, platelet plug forms 3. Coagulation(most effective): fibrin forms a mesh that traps red blood cells and platelets, forming the clot

Erythrocytes/RBC

Structure: small, bi-concave disc; no nucleus, anucleate; no cell division, amitotic; no organelles, no mitochondira; anaerobic, don't use O2; 97% of RBC is hemoglobin Function: transport respiratory gases, oxygen & carbon dioxide - bi concave shapes= the high surface area to volume ratio promotes rapid gas exchange - 97% hemoglobin= more hemoglobin, more O2 transport - anaerobic= RBCs don't have mitochondria so they're not using any of the O2 they carry to generate ATP

Describe the principle functions of blood, citing examples of each

Transportation: oxygen and nutrients to body cells, glucose; metabolic wastes: CO2 to lungs, nitrogenous wastes to kidneys; hormones to target tissues Regulation: body temperature, pH(buffers), fluid volume(osmotic pressure)=blood vessels Protection: blood loss(platelet plugs; coagulation), infection(antibodies and WBCs)

Synthetic EPO (as a drug)

Usually in athletes, specifically professional bike racers and marathon runners to increase stamina and performance. This is to increase oxygen transport capacity(aerobic endurance). Patients who produce too little EPO, which is a kidney dialysis might use EPO as a drug along with patients who have anemia which are patients who do not have enough RBCs. Consequence: polycythemia= increased hematocrit level(%RBC) increases blood viscosity, blood pressure, and heart failure. This is harder for blood to travel through blood vessels and the heart has to work harder to pump blood which leads to heart failure