1. Chapters 10 & 11: Blood & The Cardiovascular System

2. Blood Composition

3. Blood The only fluid tissue Connective tissue Components of blood – Living cells Formed elements – Non-living matrix Plasma

4. 45% =erythrocytes (red blood cells) Less than 1%= leukocytes (white blood cells) and platelets 55% = plasma Components

5. Characteristics Color range – Oxygen-rich blood = bright red – Oxygen-poor blood = dull red pH = 7.35–7.45 (slightly basic) Blood temperature = 100.4°F Volume = 5–6 liters Makes up 8% of body weight

6. Blood Plasma 90% water 10% dissolved substances – Nutrients – Salts (electrolytes) – Respiratory gases – Hormones – Plasma proteins – Waste products

7. Plasma proteins – Most abundant solutes in plasma – Made by liver – Examples: Albumin—osmotic balance; pH buffering Clotting proteins—prevents blood loss when a blood vessel is injured Antibodies—protects from pathogens

8. Acidosis – Blood becomes too acidic Alkalosis – Blood becomes too basic In each scenario, the respiratory system and kidneys help restore blood pH to normal

9. Formed Elements

10. Erythrocytes Red blood cells (RBCs) – Biconcave disks – No nucleus – Very few organelles – Large surface for gas exchange Carry oxygen Outnumber WBCs by 1000 to 1 About 5 million per mm 3 Contains hemoglobin – Iron-containing protein – Binds strongly, but reversibly, to oxygen – Each hemoglobin molecule has four oxygen binding sites – 1 RBC = 1 billion oxygen molecules

11. Leukocytes White blood cells (WBCs) Body’s defense against disease Only complete cells in blood, with a nucleus and organelles Able to move into and out of blood vessels (= diapedesis) http://www.youtube.com/watch?v=uoSwLi_CVXs Can respond to chemicals released by damaged tissues (= chemotaxis) http://www.youtube.com/watch?v=KxTYyNEbVU4&feature=related Increase in number during infection 2 kinds: – Granulocytes (particles in cytoplasm can be stained and then seen) – Agranulocytes (no particles)

12. Platelets Fragments of multinucleate cells (= megakaryocytes) Needed for the clotting process

13. Anemia = decrease in the oxygen- carrying ability of the blood – May be caused by low iron diet = tiredness Sickle cell anemia (SCA) = genetic disorder resulting in abnormally shaped hemoglobin Leukocytosis = high WBC count, indicating an infection Leukopenia = low WBC count, caused by drugs like anticancer meds Leukemia = cancer of bone marrow, makes excess WBCs Blood Disorders

14. Figure 10.3

15. Hematopoiesis & Hemostasis

16. Hematopoiesis Blood cell formation Occurs in red bone marrow – Inside most bones in children – Only in flat bones and epiphysis of humerus & femur in adults Makes ~100 billion cells (1 oz) per day

17. All blood cells are derived from a common stem cell (hemocytoblast) Hemocytoblast then differentiates (forms specialized jobs) into either: – Lymphoid stem cell: produces lymphocytes – Myeloid stem cell: produces all other formed elements

18. Figure 10.4

19. Formation of Erythrocytes Unable to divide, grow, or make proteins Live 100-120 days When worn out, RBCs are eliminated by phagocytes in the spleen or liver Lost cells are constantly replaced

20. RBC production is controlled by erythropoietin – Made by kidneys when oxygen levels in blood are too low – Negative feedback mechanism WBC production controlled by colony stimulating factors (CSFs) and interleukins Platelet production controlled by thrombopoietin Hormonal Regulation

21. Figure 10.5 Reduced O 2 levels in blood Stimulus: Decreased RBC count, decreased availability of O 2 to blood, or increased tissue demands for O 2 Increased O 2 - carrying ability of blood Erythropoietin stimulates Kidney releases erythropoietin Enhanced erythropoiesis Red bone marrow More RBCs Normal blood oxygen levels Imbalance

22. Hemostasis Stoppage of bleeding resulting from a break in a blood vessel Hemostasis involves three phases 1. Vascular spasms: narrowing of vessels to limit blood loss 2. Platelet plug formation: once vessels are damaged, platelets cling to that area 3. Coagulation : blood clotting

23. Takes 3-6 minutes Sterile gauze speeds up clotting time because more places for platelets to hold on

24. Clotting Disorders- Too Much Clotting Thrombus – A clot in an unbroken blood vessel – Can block blood flow esp around heart – May result in heart attack Embolus – A thrombus that breaks away and floats freely in the bloodstream – Can later clog vessels in critical areas such as the brain – May result in a stroke http://www.youtube.com/watch?v=AiC1V5zAba4&feature=related

25. Not Enough Clotting Thrombocytopenia – Platelet deficiency – Even normal movements can cause bleeding – Creates purple blotches on skin – Treated by vit K supplements or transfusions Hemophilia – Hereditary bleeding disorder – Normal clotting factors are missing – Minor trauma = major bleeding – Treated by tranfusion of plasma or injection of missing clotting factor

26. Human Blood Types

27. Transfusions Body can lose 15–30% of blood and still compensate; causes weakness Loss of over 30% causes shock, which can be fatal Transfusions are the only way to replace blood quickly Transfused blood must be of the same blood group

28. Human Blood Groups Antigens Surface proteins found on blood cell Act as ID tags Genetic Used to recognize foreign cells

29. Antibodies Blood proteins that recognize antigens Each antibody is specific to one antigen Binding of blood antigens and antibodies result in clumping (=agglutination) – Causes blocked vessels and kidneys – Blood cells with foreign antigens are destroyed so tissues don’t get oxygen

30. ABO Blood Groups Type A – A antigens on surface – Forms anti-B antibodies @ infancy Type B – B antigens on surface – Forms anti-A antibodies @ infancy Type AB – A and B antigens on surface – No antibodies are formed Type O – No antigens on surface – Forms anti-A and anti-B antibodies @ infancy

32. Blood type A can receive A and O blood Blood type B can receive B and O blood Blood type AB can receive A, B, AB, and O blood – Universal recipient Blood type O can only receive O blood – Universal donor

34. Table 10.3

35. Rh Blood Groups Named for Rhesus monkey that has the same antigen Humans are either Rh + (have the antigen) or Rh - (do not have the antigen) Most Americans are Rh + Problems can occur in mixing Rh + blood into a body with Rh – blood

36. Rh Dangers During Pregnancy Danger occurs only when the mother is Rh – and the child is Rh + – Mother forms antibodies – 1 st pregnancy is OK, no time to attack – 2 nd pregnancy mom’s antibodies attack; requires fetal blood transfusion RhoGAM shot can prevent buildup of anti-Rh + antibodies in mother’s blood

37. Blood Typing Process used to determine ABO group of a person Person’s blood samples are mixed with anti-A and anti-B serum If coagulation happens = wrong blood type

38. Blood Typing Figure 10.8