Composition and Functions of Blood. Text p WB 193

Transcription

1 Chapter 10 Blood

2 Composition and Functions of Blood Text p WB 193

3 Blood Transports everything that must be carried from one place to another. Nutrients, ions, gases, hormones, proteins Urea, waste Body heat WBCs RBCs

4 Blood Classified as a connective tissue only fluid tissue in the body Components of blood Living cells Formed elements Nonliving matrix Plasma

5 Blood If blood is centrifuged: Erythrocytes sink to the bottom 45% of blood hematocrit Buffy coat of leukocytes and platelets < 1% of blood Thin, whitish layer between erythrocytes and plasma Plasma rises to the top 55% of blood

6 Physical Characteristics of Blood Color range Oxygen-rich blood is scarlet red Oxygen-poor blood is dull red ph must remain between 7.35 and 7.45 Blood temperature = F Blood volume ~6 quarts (5.5 liters) Blood = 8% of body weight

7 Blood Plasma Composed of ~90% water Includes many dissolved substances: Nutrients Salts (electrolytes) Respiratory gases Hormones Plasma proteins Waste products

8 Centrifuged Blood Sample Plasma White Blood Cells & Platelets Red Blood Cells

9 Blood Plasma Proteins Most abundant solutes in plasma Most plasma proteins are made by liver Various plasma proteins include Albumin regulates osmotic pressure Clotting proteins help to stem blood loss when a blood vessel is injured Antibodies help protect the body from pathogens

10 Blood Plasma ph: Normal range of Acidosis = Blood ph is too acidic Alkalosis = Blood ph is too basic the respiratory system (CO 2 removal) and kidneys (H+ balance) help restore blood ph to normal Negative feedback mechanism

11 Formed Elements in Blood Erythrocytes Red blood cells (RBCs) Leukocytes White blood cells (WBCs) Platelets Cell fragments Lymphocyte (WBC) Platelets Erythrocytes RBC Neutrophils (WBC)

12 Hemapoiesis = making blood cells

13 All Blood Cells come from a Hemocytoblast

14 All Blood Cells come from a Hemocytoblast (simplified) Lymphoid Myeloid Basophils Eosinophils Lymphocytes Monocytes Neutrophils

15 Erythrocytes and Hematopoiesis (Red Blood Cells and Blood Cell Formation) Text p (RBCs) and p (Formation) WB 195

16 Erythrocytes (Red Blood Cells) Main function is to carry oxygen Anatomy Biconcave disks Essentially bags of hemoglobin Anucleate (no nucleus) Contain very few organelles 5 million RBCs per ml of blood is the normal count 1 ounce RBC replaced daily (average adult has 5.5 liters of blood)

17 Red Blood Cells in a Capillary

18 Hemoglobin Iron-containing protein Binds strongly, but reversibly, to oxygen Each molecule has four oxygen binding sites Each erythrocyte has 250 million hemoglobin molecules

19 Hematopoiesis: Blood Cell Formation Occurs in red bone marrow Common stem cell (hemocytoblast) Hemocytoblast differentiation

20 Formation of Red Blood Cells RBCs wear out in 100 to 120 days Anucleated (lacks a nucleus) unable to divide, grow, or synthesize proteins Worn out RBCs are eliminated by phagocytes in the spleen or liver RBCs replaced in the red bone marrow

21 Control of Erythrocyte Production Humoral negative feedback of blood O 2 levels Rate of RBC production controlled by erythropoietin When oxygen level decrease Kidneys produce and release erythropoietin Erythropoietin causes hemocytoblasts to develop into erythrocytes

22 Slide 1 Homeostasis: Normal blood oxygen levels 5 O 2 carrying ability of blood increases. 4 Enhanced erythropoiesis increases RBC count. 2 Kidney (and liver, 3 Erythropoietin to a smaller extent) releases erythropoietin. stimulates red bone marrow. 1 Stimulus Low blood O 2 carrying ability due to Decreased RBC count Decreased amount of hemoglobin Decreased availability of O Pearson Education, Inc.

23 2015 Pearson Education, Inc.

24 Red Blood Cells & Anemia Anemia is a decrease in the O 2 carrying ability of blood often due to low iron reduced ability to make hemoglobin

25 Red Blood Cells & Sickle Cell Anemia Sickle cell anemia (SCA) results from abnormally shaped hemoglobin

26 Polcythemia Disorder of excessive or abnormal increase of RBCs Caused by: bone marrow cancer (polycythemia vera) response to living at high altitudes (secondary polycythemia) High levels of RBCs slows blood flow increases blood viscosity

27 White Blood Cells Platelets Hemostasis Complete handout, read text p and p WB 194,

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29 Formation of White Blood Cells Controlled by hormones: Colony stimulating factors (CSFs) and interleukins prompt bone marrow to generate leukocytes

30 Leukocytes (white blood cells) Crucial in body s defense against disease Movement Diapedesis - moving into and out of blood vessels Amoeboid motion Positive chemotaxis Attracted to chemicals released by damaged tissues 4,800 to 10,800 WBCs per ml of blood

31 Conditions of Abnormal Number of Leukocytes Leukocytosis = High WBC count >11,000 cells/mm 3 Generally indicates an infection Leukemia = High WBC Cancerous bone marrow Leukopenia = Abnormally low leukocyte level Commonly caused by certain drugs corticosteroids anticancer agents

32 2 Types of Leukocytes Granulocytes Granules in their cytoplasm Lobed nuclei Neutrophils, eosinophils, and basophils Agranulocytes Lack visible cytoplasmic granules Spherical, oval, or kidney-shaped nuclei Lymphocytes and monocytes

33 Recognizing Leukocytes: Granules and Nucleus Shape

34 Can you identify these leukocytes?

35 Never Let Monkeys Eat Bananas! Neutrophil 40-70% Lymphocyte 20-45% Monocyte 4-8% Eosinophil 1-4% Basophil <1% List of the WBCs, from most to least abundant

36 Neutrophils Function as phagocytes at active sites of infection Numbers increase during infection 3,000 7,000 neutrophils per ml of blood Eosinophils Kill parasitic worms and play a role in allergy attacks eosinophils per ml of blood Basophils Release histamine (vasodilator) at sites of inflammation Contain heparin (anticoagulant) basophils per ml of blood

37 Lymphocytes Immune response B lymphocytes produce antibodies T lymphocytes fight tumors and viruses 1,500 3,000 lymphocytes in a cubic millimeter of blood (20 45 percent of WBCs) Monocytes (largest WBC) Function as macrophages Fight chronic infection monocytes per ml of blood

38 Platelets Derived from ruptured multinucleate cells (megakaryocyte) Needed for the clotting process (hemostasis) Platelet count: 150,000 to 400,000 per ml of blood Thrombopoietin stimulates production of platelets

39 Hemostasis

40 Hemostasis: 3 phases to stop bleeding Vasoconstriction (vascular spasms) Platelet plug Fibrin clot formation (coagulation)

41 Figure 10.6 Events of hemostasis. Slide 2 Step 1 Vascular spasms occur. Smooth muscle contracts, causing vasoconstriction Pearson Education, Inc.

42 Figure 10.6 Events of hemostasis. Slide 3 Collagen fibers Step 2 Platelet plug forms. Injury to lining of vessel exposes collagen fibers; platelets adhere. Platelets release chemicals that make nearby platelets sticky; platelet plug forms. Platelets 2015 Pearson Education, Inc.

43 Figure 10.6 Events of hemostasis. Slide 4 Fibrin Step 3 Coagulation events occur. Clotting factors present in plasma and released by injured tissue cells interact with Ca 2+ to form thrombin, the enzyme that catalyzes joining of fibrinogen molecules in plasma to fibrin. Fibrin forms a mesh that traps red blood cells and platelets, forming the clot Pearson Education, Inc.

44 Hemostasis Blood usually clots within 3 to 6 minutes The clot remains as endothelium regenerates The clot is broken down after tissue repair

45 Undesirable Clotting Thrombus A clot in an unbroken blood vessel Can be deadly in areas such as the heart Embolus A thrombus that breaks off and floats freely in the blood Can clog vessels in critical areas such as the brain

46 Blood Groups and Transfusions Text p and WB 199 Complete Blood Typing Activity

47 Blood Types: A, B, AB, O

48 Antigens and Antibodies

49 Why do Blood Types Matter?

50 Blood Groups and Transfusions Large losses of blood have serious consequences Loss of 15%-30% causes weakness Loss of >30% causes shock; can be fatal Blood transfusions are given for substantial blood loss to treat severe anemia for thrombocytopenia

51 Blood Typing & Cross Matching Blood samples are mixed with anti-a and anti-b serum Agglutination or the lack of agglutination leads to identification of blood type Typing Rh factors is done in the same manner Cross matching testing for agglutination of donor RBCs by the recipient s serum, and vice versa

52 Blood being tested Anti-A Serum Anti-B Type AB (contains antigens A and B; agglutinates with both sera) Agglutinated RBCs Type B (contains antigen B; agglutinates with anti-b serum) Type A (contains antigen A; agglutinates with anti-a serum) Type O (contains no antigens; does not agglutinate with either serum) 2015 Pearson Education, Inc.

53 Importance of Blood Type for Pregnancy Hemolytic Disease of Newborn (2 nd )

54 Fetal Rh+ and Maternal Rh- Maternal Antibodies Cause Problems for the Fetus

55 Hemolytic Disease in Newborn

56 1 st pregnancy is OK In 2 nd pregnancy, fetal RBCs are damaged RhoGAM prevents this

57 Rh Dangers During Pregnancy Danger occurs only when the mother is Rh and the father is Rh +, and the child inherits the Rh + factor RhoGAM shot can prevent buildup of anti-rh + antibodies in mother s blood The mismatch of an Rh mother carrying an Rh + baby can cause problems for the unborn child The first pregnancy usually proceeds without problems The immune system is sensitized after the first pregnancy In a second pregnancy, the mother s immune system produces antibodies to attack the Rh + blood (hemolytic disease of the newborn)

58 Developmental Aspects and REVIEW Text p WB

59 Developmental Aspects of Blood Sites of blood cell formation in fetus Fetal liver and spleen are early sites of blood cell formation Bone marrow takes over hematopoiesis by the 7 th month

60 What is the role and function of blood cells?

61 Support Videos Crash Course: Blood part 1 Crash Course: Blood part 2