Chapter 18 The Circulatory System: Blood

1. Chapter 18The Circulatory System: Blood • Blood Functions and properties • Blood cell production • Erythrocytes (RBC) • Leukocytes (WBC) • Hemostasis • Blood types

2. Functions and Properties of Blood • Function: Helps cells get nutrition, gets rid of waste • Two types of fluid: Blood and Interstitial • Blood is the transported • Interstitial fluid is the diffuser

3. Hematology • The study of blood • (Hemo = blood, -ology = study) • Blood is as unique as your fingerprints • Most cells cannot move around to get oxygen and nutrients and get rid of waste, the blood system does this for them. • INTO the BLOOD- Oxygen from the lungs, nutrients from the small intestines • OUT OF the BLOOD- Waste goes out the kidneys, skin and large intestine

4. Two Functions of Blood • 1. Transport- oxygen, nutrients, waste • 2. Protection- clotting, immunity = white blood cells (WBC), interferon, complement

5. Physical Characteristic of Blood • Alkaline: 7.4 pH avg. • 8 % of body weight (if you weighted 100 pounds, and lost all your blood you would lose 8 pounds) • Blood volume: 1.2 gallon female, 1.5 gallon male • Temperature of the blood is a little higher then body temperature, WHY? ______________

6. Components of Blood • If Blood is spun down (centrifuged), we see two parts: • 1. Plasma- liquid • If this is allowed to clot what remains is called “serum” • 2. Cells- bottom of tube • Cells of the blood are mostly red blood cells (RBCs). The rest, only 1%, is basically platelets and white blood cells (WBCs)

7. Centrifuging Blood • Centrifuging blood forces cells to separate from plasma • Hematocrit is the % of total volume of cells • Normal crit = females 42 avg., males 47 avg.

8. Hematocrit Tells Us… • Hematocrit of 40 means that 40 % of the blood is __ __ __s • Does a doctor do a hematocrit to determine the amount of WBCs or platelets? YES NO • Then what is in the buffy coat? ________ • Abnormal: • Low crit =Anemia, decreased ________ • High crit = Polycythemia

9. Polycythemia • Polycythemia is an excess of RBC • primary polycythemia is due to cancer of erythropoietic cell line in the red bone marrow • Hematocrit of 80% • secondary polycythemia from dehydration, emphysema, high altitude, or physical conditioning • Dangers of polycythemia • increased blood volume, pressure and viscosity can lead to embolism, stroke or heart failure

10. Plasma Proteins • 3 major categories of plasma proteins • Albumins are most abundant plasma protein • Globulins (antibodies) provide immune system defenses • alpha, beta and gamma globulins • Fibrinogen creates fibrin threads that causes blood to clot

11. Formation of Blood Cells • Hemopoiesis- Blood making • Lymphoid hemopoiesis occurs in widely distributed lymphoid tissues (thymus, tonsils, lymph nodes, spleen & peyers patches in intestines) • red bone marrow produces RBCs, WBCs and platelets • SEQUENCE: • 1.) Stem cells • 2.) Committed cells • 3.) Precursor Cells • 4.) Final blood cells

12. Hemopoiesis

13. Hypoxia: An important concept • Cellular oxygen deficiency is hypoxia (hypo= under, ox= oxygen) • Ischemia is a from of hypoxia due to obstruction of blood flow (as by the narrowing of arteries by spasm or disease) • This can cause cell death (necrosis) • Occurs in many situations: • High altitude • Anemia • Iron or B12 deficiency resulting in anemia • Circulatory problems

14. Erythrocyte Homeostasis • Classic negative feedback control • drop in RBC count causes hypoxemia to kidneys • stimulation of bone marrow • RBC count  in 3-4 days • Stimulus for erythropoiesis • Hypoxia is a stimulus for blood production such as: • low levels of atmospheric O2 (high altitude) • increase in exercise • Circulatory problems • Anemia from Iron or B12 deficiency

15. Erythropoiesis: Making RBCs

16. Lab Test for RBC creation • Reticulocyte count (“Tic”) measures the rate of erythropoiesis and so can give an indication of RBC creation. • Normal= avg. 1 %--- because about 1% of RBCs are replaced in a day therefore about 1% of the blood is reticulocytes • Low tic count = red bone marrow not working. Cause = nutritional deficiency or leukemia • High tic count = usually good sign, response to iron therapy

17. Red Blood Cells (RBCs) • RBCs are called erythrocytes (red, cells) • Oxygen-carrying cells • Contains oxygen-carrying protein called hemoglobin • Anatomy- 7.5 microns, biconcave disc- can get into small places • large surface area helps diffusion of gases • No nucleus or organelles so ample space for oxygen • Gets energy anaerobically • So it doesn’t need the oxygen that it’s carrying

18. Erythrocytes on a Needle

19. Leukocyte Production (Leukopoiesis) • Some lymphocytes leave bone marrow unfinished • go to thymus to complete their development (T cells) • Circulating WBCs do not stay in bloodstream • granulocytes leave in 8 hours • monocytes leave and transform into macrophages • WBCs provide long-term immunity lasting decades

20. Platelet Production • Cells called megakaryocyte create platelets • Cytoplasm of the cell splits off creating cell fragments that enter the bloodstream as platelets (live for 10 days) • some stored in spleen & released as needed • Platelets are important for _________

21. Erythrocytes and Hemoglobin Tests • RBC count & hemoglobin concentration indicate the amount of oxygen the blood can carry • hemoglobin concentration of whole blood • men avg. 15; women avg. 14 • RBC count • men 5.5 million avg.; women 5 million avg.

22. Erythrocyte Death & Disposal • RBCs live for 120 days • membrane fragility -- lysis in narrow channels in the spleen through a process called ____________ • Macrophages in spleen • remove iron from heme • convert heme to bilirubin (yellow pigment) • Why can’t RBCs repair themselves? • Bilirubin is converted to urobilogen in the intestine by bacteria giving fecal matter it’s brown color

23. Anemia • Causes of anemia • Decreased RBCs or hemoglobin • inadequate dietary vitamin B12 • Or lack of intrinsic factor in the stomach (pernicious anemia) • iron-deficiency anemia • If in males and post-menopausal females check for hemorrhage • aplastic anemia can be drug induced marrow destruction • Anemia (normocytic): causes ABCD:Acute blood lossBone marrow failureChronic dietary deficiencyDestruction (hemolysis)

24. Anemia • Effects of anemia • FATigue • Heart races • Edema • Low blood pressure • Pallor • Shortness of breath • (Fat HELPS)

25. Sickle-Cell Disease • Sickle-Cell is hereditary Hemoglobin defect of African Americans • sickle-cell disease individual has shortened life • cell stickiness causes agglutination and blocked vessels • intense pain, kidney and heart failure, paralysis, and stroke • Sickle cell Disease-codominant genetic disorder, resistant to malaria. Why? • Because sickle cells hemoglobin is indigestible to malaria parasites

26. Sickle-Cell Diseased Erythrocyte

27. Blood Types • The surface of RBCs contain genetically determined antigens (antibody generator) these determine the blood types • Major blood types are: ABO and Rh • ABO blood group are based on people that have blood antigens A or B • If you have A antigen on your RBCs you are type A, if you have B antigens you are type B, and type AB has both antigens but if you don’t have any A or B antigens you are type O. • Remember: This applies to incoming blood

28. Blood Type Diet Theory • Type O is said to be the Original blood type, no antigens. These were the hunters. Diet is meat based. Native Americans are 79% type Os. • Type A is the Agrarian blood type. These are the farmers. Diet is vegetarian.

29. ABO Blood Typing • Agglutination is the term for blood clumping • For example: type A has agglutination on the left which tells us this blood reacted with anti-A • Type AB has agglutination to both ____ and ______

30. Blood Swapping • Type AB- universal ABceptor, person can be infused with any type of blood • Type O- universal dOnor, can give their blood to anyone • Caveat: Remember that blood contains other antigens and antibodies than ABO, so specific typing should always be done to avoid Agglutination (clumping) • Agglutination is massive clumping which is distinct from normal clotting (like from a cut)

31. The Rh Group • Rh or D agglutinogens discovered in Rhesus monkey • If you have the Rh antigen you are Rh+ • If you don’t have the Rh antigen you are Rh- • Anti-D agglutinins are not normally present in blood • formed only in individuals exposed to Rh+ blood • Rh- pregnant woman carrying an Rh+ fetus • no problems result with the first pregnancy • hemolytic disease of the newborn (erythroblastosis fetalis) occurs if mother has formed antibodies & is pregnant with 2nd Rh+ child • RhoGAM is given to pregnant woman to prevent antibody formation and prevent any future problems • Relate disease: Peanut butter should be avoided in ____ peanut butter cup syndrome

32. Hemolytic Disease of Newborn • Mother’s antibodies attack fetal blood causing toxic brain syndrome from excessive bilirubin in blood from hemolysis • treatment is phototherapy to degrade bilirubin or complete exchange transfusion to replace all the infant’s blood • http://nobelprize.org/educational_games/medicine/landsteiner/

33. GRANULAR Neutrophils Eosinophils Basophiles AGRANULAR Lymphocytes Monocytes White Blood Cells (WBCs)WBC are also called Leukocytes (leuko= white, cyte= old cell)-Have nucleus but no hemoglobin_____________________________________

34. Granular Leukocyte (WBCs) • Granulocytes- when stained these show granules under the microscope • basophils – non-abundant, dark violet granules (<1%) • large U- to S-shaped nucleus hidden by granules • eosinophils - pink-orange granules & bilobed nucleus (2-4%) • neutrophils - multilobed nucleus (60-70%) • fine reddish to violet granules in cytoplasm • Older neutrophils are called polymorphonuclear (PMN) leukocytes or “POLYS” • BEN

35. Granulocyte Functions • Neutrophils ( in bacterial infections) • phagocytosis of bacteria • releases antimicrobial chemicals • Eosinophils ( in parasitic infections or allergies) • phagocytosis of antigen-antibody complexes, allergens & inflammatory chemicals • release enzymes destroy parasites such as worms • Basophils ( in chicken pox, sinusitis, diabetes) • secrete histamine (vasodilator) • secrete heparin (anticoagulant)

36. Agranular Leukocyte (WBCs) • These cells do contain granules but do not stainand are small • Monocytes- the cops of the body • The blood is a transport system (cop car) for monocytes as they fight infection in tissues • They go into tissue and become macrophages (macro= big, phage= eater) • Lymphocytes- cytoplasm stains and forms a blue rim around the cell • B cells, T cells and Killer cells

37. Agranulocyte Functions • Lymphocytes ( in diverse infections & immune responses) • destroy cancer & foreign cells & virally infected cells • coordinate actions of other immune cells • secrete antibodies & provide immune memory • Monocytes ( in viral infections & inflammation) • differentiate into macrophages • phagocytize pathogens and debris

38. LYMPHOCYTES • Major types are B cells, T cells, and natural killer cells which are major warriors in the immune response • B cells- from Bone marrow • Good at destroying Bacteria • T cells- Formed in bone marrow but matures in the Thymus gland • Good at attacking virus, fungi, cancer cells and Transplanted organs • Killer cells- kill microbes and tumor cells

39. INCREASED Neutrophils- bacteria Lymphocytes- virus Monocytes-virus, fungus Eosinophils-allergy, parasites Basophils- allergy, cancer DECREASED Neutrophils- radiation, drugs, nutrition deficiency Lymphocytes- chronic illness Monocytes-bone marrow depression Eosinophils-drugs, stress Basophils- pregnancy, stress Increased and Decreased WBCs

40. WBC Pathology • Leukocytosis- increased WBCs • usually normal • Due to stresses such as microbes and strenuous exercise • Leukopenia- decreased WBCs • Abnormal • due to shock or drug reactions or disease

41. WBC pathology- Leukemia • Leukemia = cancer of hemopoietic tissue • Uncontrolled WBC production • Subject to opportunistic infection, anemia • Acute Leukemia- = immature WBC • Chronic Leukemia- = too many WBCs • Remission (disappearing) and exacerbation (occurrence) common

42. Normal and Leukemia Blood Smears • Normal blood ratio = 700 RBCs to 1 WBC

43. The Action of WBCs • WBCs leave the bloodstream by emigration • Phagocytosis- the process of the WBC eating an invader, a bacteria • Chemotaxis- the process of attracting phagocytes, caused by toxins that are produced by microbes destroying tissue • Lysozymes- enzymes that the phagocytes use to destroy bacteria • A Differential WBC count (Diff) is counting of the different WBC, determining the percentage of each type of WBC helps in the diagnosis

44. Of Thrombosis and Embolism • Unwanted coagulation • Thrombosis = the formation of a clot of blood within a blood vessel • Thrombosis can create a thrombus • Thrombus = a clot of blood formed within a blood vessel and remaining attached to its place of origin • most likely to occur in leg veins of inactive people • the thrombus may break off causing an embolus • An embolus is an abnormal particle circulating in the blood • An embolus could travel from veins to lungs producing pulmonary embolism • death from hypoxia may occur

45. Out, Damned Clot! After four days, a fibrin clot (red) is on its way out of a microvessel (green) in a mouse's brain. Tiny blood vessels in the brains of mice have a novel way of dealing with clots — they pack them up and shove them out, right through the vessel wall. Does this happen in Humans?

46. Necrosis • Necrosis = Tissue death • Infarct = an area of necrosis in a tissue or organ resulting from obstruction of the local circulation • Infarction is the process of forming an infarct • may occur if an embolus or thrombus blocks blood supply to an organ (MI or stroke) • 650,000 Americans die annually of thromboembolism

47. GOOD Hemostatis- the process of stopping the bleeding process BAD Thrombosis- blood clotting in vessels forming BLOOD CLOTS Embolism- a blood clot, or air bubble or fat, that blocks a vessel causing Ischemia Hemorrhage- blood loss. Can be from drugs like Celebrex, anticoagulants, or vessel tear COAGULATION(BLOOD COTTING)Blood has the ability to clot together. This is good and bad, depending.

48. Anticoagulant Drugs • Warfarin or Coumadin (rat poison) may be given to people who have a tendency to produce blood clots, like in atrial fibrillation • “Poisons and medicine are oftentimes the same substance given with different intents.” • -Peter Mere Latham, MD (1789-1875) • Their blood must be monitored for possible hemorrhage • These drugs are antagonists to vitamin K • Streptokinase- produced from streptococcal bacteria is a thrombolytic agent, it dissolves blood clots both good and bad. Used in stroke patients.

49. Hemophilia • Genetic lack of any clotting factor affecting the patient’s blood coagulation • Sex-linked recessive in males (inherit from mother) • Physical exertion causes bleeding & excruciating pain

50. Hemostasis - The Control of Bleeding • Platelet plug is formed by pseudopods that adhere to the vessels and contract drawing the vessel together • Fibrin, a sticky protein, comes from the plasma to trap blood cells