BIO 142 Lecture: Unit 2 Blood

39. Describe the process by which aspirin functions to inhibit platelet aggregation.

(a) Clinical Correlation: Aspirin inactivates the cyclooxygenase (COX) enzyme, which is necessary for the production of prostaglandins, which are then converted to thromboxane A2 by platelets. The reduction of thromboxane A2 prevents vasoconstriction and prevents platelet aggregation. (b) Aspirin also inhibits prostacyclin production by endothelial cells.

8. State the number of hemoglobin molecules per RBC and calculate the number of oxygen molecules transported by a RBC if the contained hemoglobin is RBC Is 100% saturated.

- Each RBC contains approximately 250 million hemoglobin molecules. -100% oxygen saturation is 4 O2 molecules per hemoglobin, so 4x250 million is 1 billion O2 molecules per RBC.

15. List 3 causes that lead to a low reticulocyte count and 2 causes that lead to a high reticulocyte count.

- Low production may be caused by a lack of vitamin B12, folic acid, or iron in the diet; or by an illness affecting the bone marrow such as cancer. - The reticulocyte count rises when the bone marrow makes more red cells in response to blood loss or treatment of anemia.

54. Define leukemia and contrast acute leukemia to chronic leukemia.

- The presence of immature and abnormal WBC's in the circulating blood and in most cases suppress other cells in the marrow leading to symptoms associated with decreased numbers of RBC's, platelets, and WBC's.

25a. Define anemia.

- decrease in the number of RBCs or hemoglobin

25. Define polycythemia

- increase in the number of RBCs

54a. Acute leukemia

- replacement of bone marrow by leukocyte blast cells causing anemia, susceptibility of infection, and blood loss due to bleeding

18. State the lifespan of RBCs.

-120 days

48. Explain the mechanism by which heparin, Coumadin, and direct thrombin inhibitors (DTI) function as anticoagulants.

-A newer class of anticoagulants is the direct thrombin inhibitor. The drugs in this class function by reversibly binding to thrombin, which prevents its ability to convert fibrinogen to fibrin. -Normal plasma contains several anticoagulants. Antithrombin III is one anticoagulant found in plasma that inhibits the action of thrombin and other clotting factors. - Heparin, which is produced by mast cells and basophils, accelerates the activation of antithrombin III. Heparin is used clinically as an anticoagulant.

14a. explain the relationship between a reticulocyte count and rate of erythropoiesis.

-A reticulocyte count provides information about the rate at which the bone marrow is producing red cells. - A low reticulocyte count indicates that the bone marrow is not producing a normal number of red blood cells.

35. Describe the immunological basis for ABO and Rh blood typing,,

-A. The surfaces of RBC's contain genetically determined blood group antigens called agglutinogens or isoantigens. B. Blood is categorized into different blood groups based on the presence or absence of isoantigens. (The blood type is named according to the type of antigen found on the surface.) C. Two major blood groups are ABO and Rh. There are also 23 other blood groups.

23. In a person experiencing a bile duct obstruction, predict the type of bilirubin elevated in the blood, whether urobilinogen levels in the GI tract would increase or decrease, and what would result with the color of feces and urine.

-Conjugated bilirubin would be elevated. -Urobilinogen levels would increase -The colors of feces and urine would darken as there would be excess being excreted.

36. Explain the blood type incompatibility that occurs between a mother and fetus when a fetus develops the condition called hemolytic disease of the newborn.

-Hemolytic disease of the newborn (HDN) is when the red blood cells of an unborn baby (fetus) or newborn are destroyed. This breakdown of red blood cells is called hemolysis. It can lead to low amounts of red blood cells (anemia) and other problems. -Such can occur when the mother is Rh- and the fetus is Rh+

54b. Chronic leukemia

-Mainly seen in patients over the age of 50 and is characterized by proliferation of small mature lymphocytes in the marrow and initially spares other hematopoietic tissue. As the disease progresses other cells in the marrow are affected

10. Define carbaminohemoglobin

-The globin portion of hemoglobin binds reversibly to CO2, which allows for the transport of a small amount of CO2 throughout the body. -a compound of hemoglobin and carbon dioxide, and is one of the forms in which carbon dioxide exists in the blood.

9. Define oxyhemoglobin

-The heme portion of hemoglobin binds reversibly to O2, which allows for the transport of O2 throughout the blood. -The oxygen-loaded form of hemoglobin, the predominant protein in red blood cells. Hemoglobin is a protein molecule that binds to oxygen. -Hemoglobin forms an unstable, reversible bond with oxygen. -In its oxygen-loaded form, it is called oxyhemoglobin and is bright red.

24. In a person experiencing excessive hemolysis, predict the type of bilirubin elevated in the blood and whether urobilinogen levels in the GI tract would be increased or decreased.

-There would be an elevated amount of unconjugated bilirubin. -Urobilinogen would increase.

16. Explain the relationship between Vitamin B12, intrinsic factor, and erythropoiesis.

-Vitamin B12 and folic acid are needed for DNA synthesis. -Intrinsic factor, which is secreted by parietal cells in the epithelial lining of the stomach, is needed for proper vitamin B12 absorption in the ileum.

17. Predict how inadequate production of intrinsic factor affects erythropoiesis.

-Without intrinsic factor, vitamin B12 would be unable to be absorbed in the lower intestines, and without B12, DNA synthesis would not occur.

19. Explain the process by which a worn out RBC is removed from the blood

-Worn out RBC's are phagocytized by macrophages in the spleen, liver, and red bone marrow. -The RBC's hemoglobin is recycled.

11a. Define erythropoietin

-a hormone secreted by the kidneys that increases the rate of production of red blood cells in response to falling levels of oxygen in the tissues.

35b. name the universal donor blood type, and the universal recipient blood type. (This is mainly covered in lab.)

-individuals with type O Rh D negative are universal donors -those with type AB Rh D positive blood are called universal recipients

11. Define erythropoiesis

-the production of red blood cells.

21. Explain the two pathways for excretion of urobilinogen (fecal pathway and urine pathway).

1) Most of the urobilinogen in the intestine remains in the intestine and will defecated. While in the intestine, the urobilinogen is oxidized to stercobilin, which gives feces its characteristic brown color. 2) Some Urobilinogen is reabsorbed by the intestine and is transported back to the liver by the hepatic portal system. The majority of the urobilinogen that passes through the portal vein in the liver is taken up by hepatocytes and excreted back into the bile. 3) Some of the urobilinogen passes through the liver without being taken up by hepatocytes. It is then filtered out of the blood by the kidney and is excreted from the body in the urine. When urobilinogen is oxidized it is converted to urobilin, which is responsible for giving urine its characteristic yellow color.

13. Describe how hypoxia leads to an increased production of erythrocytes.

1. As a result, the kidney increases the production and release of erythropoietin. 2. Erythropoietin circulates through the blood to the red bone marrow. 3. In the bone marrow erythropoietin stimulates erythropoiesis.

2. List 5 ways in which blood functions in body regulation.

1. Helps regulate the pH of body fluids 2. Helps to maintain body temperature

3. List 5 ways in which blood functions in body protection.

1. Hemostasis: Blood has the ability to clot, which protects the body against the excessive fluid loss. 2. Leukocytes protect the body against disease and infection.

34. Differentiate the WBC's formed from the myeloid cell line from the WBC's formed from the lymphoid cell line during hamatopoeisis.

1. Myeloid stem cells become RBCs, platelets and all WBCs except lymphocytes. 2. Lymphoid stem cells become lymphocytes, which then differentiate into either B lymphocytes or T lymphocytes.

1. List 5 ways in which blood functions in transportation in the body.

1. Oxygen is transported from the lungs to the tissues. 2. CO2 is transported from the tissues to the lungs. 3. Nutrients are transported from the GI tract to body cells. 4. Heat and cellular waste products are transported away from cells. 5. Hormones are transported from endocrine glands to body cells.

7. Describe the shape and structure of an erythrocyte.

1. Small flexible cells shaped like a biconcave disc (increases surface area for more efficient gas exchange). 2. Mature cells are anucleate and lack organelles, such as mitochondria so the cell doesn't consume the oxygen it is transporting. 3. Mature cells contain a selectively permeable membrane, cytosol, and hemoglobin; they are described as "bags of hemoglobin." Each RBC contains approximately 250 million hemoglobin molecules.

49. List the measurements and calculations that are provided in a complete blood count (CBC).

1. The number of RBC's, WBC's, and platelets 2. The amount of hemoglobin 3. Hematocrit 4. MCV: mean corpuscular volume: average volume of a RBC 5. MCH: Mean Corpuscular hemoglobin: average Hb per RBC 6. MCHC: mean corpuscular hemoglobin concentration

33. State the hormones that stimulate the production of erythrocytes and platelets.

1. erythropoietin increases the number of RBC precursors 2. thrombopoeitin increases the number of platelet precursors 3. Hormones that stimulate each WBC precursor are categorized into a group of hormones called colony stimulating factors (CSFs).

5. List the relative percentages of water, proteins, and other solutes that compose blood.

1.91% of plasma consists of water. 2. 2% consists of solutes other than proteins, such as nutrients, gases, hormones, cellular wastes, and ions. 3. 7% consists of proteins. a

41. Define coagulation.

3. A complex sequence of steps that involves over 30 substances but eventually leads to the conversion of circulating fibrinogen into the insoluble protein fibrin. 4. The process involves clotting factors found in the plasma (Ca++ and 11 different proteins). 5. Two pathways

51. Define anemia.

A decrease in the number of erythrocytes or the amount of hemoglobin

37. Define hemostasis.

A series of reactions that stops bleeding

31. State the normal range for platelets in a blood sample, describe their structure, and in general terms, state their function.

A. 150,000-350,000 mm3 B. Platelets are fragments of cells enclosed by a plasma membrane. C. Platelets help stop blood loss from damaged vessels by forming a platelet plug. They also contain granules that promote blood clotting.

55. Define jaundice and describes the signs associated with jaundice.

A. Elevated levels of bilirubin in the blood B. Kernicterus: elevated levels of bilirubin in an infant because the liver's mechanism of clearance is not fully developed, which can cause brain damage.

12. List 3 conditions that lead to hypoxia.

A. reduced number of RBC's B. reduced availability of O2 C. increased tissue demands for O2

45. Explain the function of fibroblasts and mitotic endothelial cells during clot retraction.

As clot retraction occurs, fibroblasts divide and form a connective tissue patch in the area, while endothelial cells multiply to restore the lining.

29c. Describe basophils

Basophils: (Granulocytes ) a) less than 1% of total WBCs b) rarest of the leukocytes c) Cytoplasm contains coarse histamine-containing granules. d) IGE antibodies, produced by plasma cells in response to an allergen (antigen), bind to receptors on basophils (and mast cells). Upon the next exposure to the allergen, the allergen binds to the antibody and causes the cell to release substances such as histamine and heparin. e) Histamine is an inflammatory chemical that is a vasodilator and also attracts other WBCs to the inflamed area.

46. Explain the process of fibrinolysis.

Fibrinolysis: the removal of an unneeded clot after healing has taken place. 1. Plasminogen, which was trapped in the clot when it was formed, is converted into plasmin by a series of reactions that is initiated by a protein released by endothelial cells (thrombomodulin). 2. Plasmin is an enzyme that gradually breaks down the fibrin strands.

6. Define hematocrit and buffy coat.

Formed elements: consist of erythrocytes, leukocytes, and platelets 1. Buffy coat: portion of blood that contains WBC's 2. Hematocrit: portion of blood that consists of RBC's

53. For each of the following anemias, state the factor or factors that lead to the development of the anemia: iron deficiency, sickle cell, pernicious, hemorrhagic, hemolytic, and aplastic.

Iron deficiency anemia: 1. normal hemoglobin synthesis can not occur because of inadequate reserves of iron 2. lack of iron I. Pernicious anemia: The lack of intrinsic factor leads to a decrease absorption of vitamin B12. J. Hemorrhagic anemia: The loss of RBC's due to excessive bleeding. G. Hemolytic anemia: 1. destruction of RBC's prematurely 2. hematocrit and hemoglobin concentrations are low and reticulocyte count is elevated 3. can be a result of a parasitic infection, toxins, or antibodies from incompatible blood B. Aplastic anemia 1. The bone marrow fails to produce new erythrocytes. 2. Can be fatal unless stem cells repopulate or a bone marrow transplant is performed C. Sickle cell anemia: 1. A genetic disorder resulting from the abnormal formation of hemoglobin 2. When the hemoglobin is at low oxygen saturations the erythrocyte will deform and take on a sickle shape. 3. Sickle cells will get stuck in small blood vessels and obstruct blood flow. 4. Sickle cells protect against malaria.

52. Describe the signs and symptoms associated with anemia.

Leads to fatigue, intolerance of cold, and paleness

40. State two mechanisms that restrict platelet aggregation at an injury site.

Platelet aggregation is controlled and restricted to the injury site. Platelet aggregation is inhibited by... (1) Prostacyclin produced by endothelial cells (2) Compounds released by WBC's (3) Circulating plasma enzymes the break down ADP (4) The formation of a clot, which reinforces the platelet plug but separates it from the circulation.

50. Explain leukocyte differential and state one possible reason for an increase in each type of WBC.

Leukocyte Differential: 1. Lists the different percentages of the different types of leukocytes in a blood sample 2. Diagnostic value: The relative proportions of the types of WBC's may change with illnesses. a) increased neutrophils: bacterial infections b) increased lymphocytes: viral infection c) increased monocytes: chronic infection d) increased basophils: allergic reactions e) increased eosinophils: allergic reactions, parasitic infections .

30. Define leukocytosis and leukopenia.

Leukocytosis: increased number of WBCs . Leukopenia: decreased number of WBCs

4. Define plasma

Liquid portion of blood

29d. Describe lymphocytes

Lymphocytes: (Agranulocyte) a) 25-33% of total WBCs b) They contain a large dark purple nucleus that occupies most of the cell volume c) The nucleus is usually surrounded by a thin rim of cytoplasm. d) Most lymphocytes are found in the lymphatic system. e) Lymphocytes can differentiate into either T cells or B cells. (1) T cells: There are two types of T cells. (a) The T8 cell destroys cells to which it binds and is responsible for destroying cells infected with viruses and tumor cells. (b) T4 cells enhance an immune response by releasing chemicals that attract other immune cells and increase inflammation. (2) B cells: give rise to plasma cells, which produce antibodies that are released into the blood

29e. Describe monocytes

Monocytes: (Agranulocyte) e) 3-7% of total WBCs f) Largest of the WBCs g) The nucleus is large and is shaped like a horseshoe. h) They are very motile cells that leave the blood and become macrophages.

29a. Describe neutrophil

Neutrophils (polymorphonuclear leukocytes): (Granulocytes ) a) 54-62% of total WBCs b) The nucleus consists of 3 to 6 lobes. c) The cytoplasm contains granules that are considered lysosomes. d) Neutrophils are chemically attracted to sites of inflammation and are phagocytes. e) They commonly phagocytize bacteria and destroy them by the lysosomes in the granules. f) Neutrophils increase in number during bacterial infections.

32. Define hematopoiesis.

The formation of blood cells

38. Describe the process of platelet aggregation. Be sure to include the functions of calcium, ADP, and Thromboxane A2 in the process.

a) As a result of adhesion, the platelets are activated causing them to extend projections that enable them to contact and interact with one another. They also release chemicals to sustain vasoconstriction, stimulate further platelet aggregation, and stimulate blood clotting. (1) Calcium is released, which is necessary for platelet aggregation and the blood clotting process . (2) ADP (adenosine diphosphate) stimulates platelet aggregation and secretion (3) Thromboxane A2 stimulates vascular spasm and stimulates platelet aggregation.

20. Explain and diagram the process by which heme is ultimately converted to urobilinogen.

a) The globin portion is separated from the heme and broken down into amino acids, which can be used by other cells for protein synthesis. b) The heme is broken down into iron and biliverdin. c) Iron is carried by a plasma protein called transferrin to the liver for storage. d) When iron is needed for hemoglobin synthesis it will be transported from storage to the red bone marrow. e) The non-iron portion of heme is converted into biliverdin (a greenish pigment). f) Biliverdin is quickly converted into bilirubin (yellowish pigment). g) Bilirubin enters the bloodstream and binds to albumin to be transported to the liver. h) In the liver, bilirubin is taken up by hepatocytes. i) In the hepatocytes, bilirubin is conjugated with glucuronic acid, which is catalyzed by glucuronyl transferase in the endoplasmic reticulum. j) Conjugated bilirubin is water soluble and is transported across the cell membrane into the bile and transported to the small intestine by the bile duct system. k) Conjugated bilirubin is eventually converted into urobilinogen by bacteria in the intestine.

19a. Describe how hemoglobin is recycled.

a) The globin portion is separated from the heme and broken down into amino acids, which can be used by other cells for protein synthesis. b) The heme is broken down into iron and biliverdin. c) Iron is carried by a plasma protein called transferrin to the liver for storage. d) When iron is needed for hemoglobin synthesis it will be transported from storage to the red bone marrow. e) The non-iron portion of heme is converted into biliverdin (a greenish pigment).

43. Explain all the steps in the common pathway of coagulation and predict the consequence of lacking a normal enzyme that is involved in the pathway.

a) stage 1: prothrombinase is formed b) stage 2: prothrombinase converts prothrombin into thrombin c) stage 3: thrombin converts soluble fibrinogen into insoluble fibrin d) fibrin: long hair-like strands that glues the platelets together forming a web that is the structural foundation of the clot e) Thrombin stimulates the release of tissue factor from endothelial cells and stimulates platelets to release chemicals. This action by thrombin sets up a positive feedback system.

56. Define hemophilia.

genetic disorder due to the lack of clotting factors that results in uncontrollable bleeding

27. State the two categories into which WBCs are classified.

granulocytes and agranulocytes

26. State the lifespan for leukocytes.

usually only survive for a few hours or days

14. Define reticulocyte

young RBC with a small amount of ER

42. Contrast the intrinsic pathway of coagulation to the extrinsic pathway of coagulation.

Extrinisic: Pathway begins by the release of a chemical called tissue factor (TF) by damaged endothelial cells and other damaged cells. Intrinsic: The pathway begins when the proenzyme Factor XII is exposed to collagen or other negatively charged surfaces.

22. Contrast conjugated bilirubin to unconjugated bilirubin and state where each type is normally located.

Bilirubin: a yellow to orange bile pigment produced by the breakdown of heme and reduction of biliverdin; it normally circulates in plasma and is taken up by liver cells and conjugated to form bilirubin diglucuronide, the water-soluble pigment excreted in the bile. Bilirubin. The metabolism of bilirubin. Once bile is taken up and conjugated by the liver, some leakage of bilirubin mono- and diglucuronides does occur, but these normally account for less than 5% of circulating bilirubin. In bile, more than 80% is conjugated as the diglucuronide form. From Aspinall and Taylor-Robinson, 2001. Failure of the liver cells to excrete bile, or obstruction of the bile ducts, can cause an increased amount of bilirubin in the body fluids and lead to obstructive jaundice. Clinical correlation: 1) Excessive conjugated bilirubin in the bloodstream is indicative of a blockage of the bile duct system. Typically this type of blockage is the result of gall stones. It could also result from liver damage, such as cirrhosis that is compressing the bile canaliculi within the liver 2) Unconjugated bilirubin in the blood stream is usually indicative of either damage to the hepatocytes or excessive destruction of RBC's (hemolysis). 3) Excessive urobilinogen in the urine is indicative of cirrhosis or other liver dysfunction.

4a. Describe the formed elements of plasma and describe the process used to quickly separate them.

Blood is composed of two portions (Plasma and formed elements) which can be separated from one another by placing the blood in a glass tube and spinning it in a centrifuge.

47. Explain the mechanism by which Clopidogrel (Plavix) prevents platelet aggregation.

Clopidogrel (Plavix) inhibits platelet aggregation by blocking a specific type of ADP receptor located within the membranes of platelets.

44. State the function of clot retraction and when it occurs during hemostasis.

Clot retraction: Contractile proteins within platelets contract and pull on the fibrin strands resulting in a closer proximity of the ruptured edges.

35a. determine blood transfusion compatibility using the ABO and Rh blood groups

D. ABO Group 1. Antigens (agglutinogens) A and B determine blood type. 2. Antibodies (agglutinins) A and B are found in the plasma and react with antigens that are foreign to the individual. 3. Diagram and explanation will be given during lecture. E. Rh blood type 1. Individuals who have Rh antigens on the surface of erythrocytes are Rh+. 2. Individuals who lack Rh antigens are Rh-. 3. hemolytic disease of the newborn (erythroblastosis fetalis)

28. Define diapedesis and chemotaxis.

Diapedesis: The movement or passage of blood cells, especially white blood cells, through intact capillary walls into surrounding body tissue. Also called migration. Chemotaxsis: the movement of an organism in response to a chemical stimulus. Somatic cells, bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemicals in their environment

29b. Describe eosinophils

Eosinophils: (Granulocytes ) a) 1-3% of total WBCs b) The nucleus is bi-lobed. c) The granules in the cytoplasm stain red. d) They combat against parasitic worms that are too large to be phagocytized. e) Enzymes are released from granules and digest the parasite's surface. f) They lessen the severity of allergic episodes by releasing substances that inactivate inflammatory chemicals released by mast cells and basophils (histamine and heparin) during allergic reactions.