Blood - 🩸 -compressed.pdf

 Blood ▪ Blood transports everything that must be carried from one place to another, such as: ▪ Nutrients ▪ Wastes ▪ Hormones ▪ Body heat © 2018 Pearson Education, Ltd.  Components of Blood ▪ Blood is the only fluid tissue, a type of co...

 Blood ▪ Blood transports everything that must be carried from one place to another, such as: ▪ Nutrients ▪ Wastes ▪ Hormones ▪ Body heat © 2018 Pearson Education, Ltd.  Components of Blood ▪ Blood is the only fluid tissue, a type of connective tissue, in the human body ▪ Components of blood ▪ Formed elements (living cells) ▪ Plasma (nonliving fluid matrix) © 2018 Pearson Education, Ltd.  Components of Blood ▪ When blood is separated: ▪ Erythrocytes sink to the bottom (45 percent of blood, a percentage known as the hematocrit) ▪ Buffy coat contains leukocytes and platelets (less than 1 percent of blood) ▪ Buffy coat is a thin, whitish layer between the erythrocytes and plasma ▪ Plasma rises to the top (55 percent of blood) © 2018 Pearson Education, Ltd. Figure 10.1 The composition of blood. Plasma 55% Constituent Major Functions Formed elements (cells) 45% Water 90% of plasma Cell Type Number Functions volume; solvent (per mm3 of blood) for carrying other Erythrocytes substances; absorbs heat (red blood cells) 4–6 million Transport oxygen and help transport Salts (electrolytes) carbon dioxide Sodium Osmotic balance, Potassium pH buffering, Leukocytes Calcium regulation of 4,800–10,800 Defense and (white blood cells) Magnesium membrane immunity Chloride permeability Bicarbonate Lymphocyte Plasma proteins Basophil Albumin Osmotic balance, pH buffering Clotting of blood Eosinophil Fibrinogen Globulins Defense (antibodies) and lipid transport Neutrophil Monocyte Substances transported by blood Platelets Nutrients (glucose, fatty acids, amino 250,000–400,000 Blood clotting acids, vitamins) Waste products of metabolism (urea, uric acid) Respiratory gases (O2 and CO2) Hormones (steroids and thyroid hormone are carried by plasma proteins) © 2018 Pearson Education, Ltd.  Physical Characteristics and Volume ▪ Blood characteristics ▪ Sticky, opaque fluid ▪ Heavier and thicker than water ▪ Color range ▪ Oxygen-rich blood is scarlet red ▪ Oxygen-poor blood is dull red or purple ▪ Metallic, salty taste ▪ Blood pH is slightly alkaline, between 7.35 and 7.45 ▪ Blood temperature is slightly higher than body temperature, at 38ºC or 100.4ºF © 2018 Pearson Education, Ltd.  Plasma ▪ 90 percent water ▪ Straw-colored fluid ▪ Includes many dissolved substances ▪ Nutrients ▪ Salts (electrolytes) ▪ Respiratory gases ▪ Hormones ▪ Plasma proteins ▪ Waste products © 2018 Pearson Education, Ltd.  Plasma ▪ Plasma proteins ▪ Most abundant solutes in plasma ▪ Most are made by the liver ▪ Include: ▪ Albumin—an important blood buffer and contributes to osmotic pressure ▪ Clotting proteins—help to stem blood loss when a blood vessel is injured ▪ Antibodies—help protect the body from pathogens © 2018 Pearson Education, Ltd.  Formed Elements ▪ Erythrocytes ▪ Red blood cells (RBCs) ▪ Leukocytes ▪ White blood cells (WBCs) ▪ Platelets ▪ Cell fragments © 2018 Pearson Education, Ltd. Figure 10.2 Photomicrograph of a blood smear. Lymphocyte Platelets Erythrocytes Neutrophils © 2018 Pearson Education, Ltd.  Formed Elements ▪ Erythrocytes (red blood cells, or RBCs) ▪ Main function is to carry oxygen ▪ RBCs differ from other blood cells ▪ Anucleate (no nucleus) ▪ Contain few organelles; lack mitochondria ▪ Essentially bags of hemoglobin (Hb) ▪ Shaped like biconcave discs ▪ Normal count is 5 million RBCs per cubic millimeter (mm3) of blood © 2018 Pearson Education, Ltd.  Formed Elements ▪ Erythrocytes (continued) ▪ Hemoglobin is an iron-bearing protein ▪ Binds oxygen ▪ Each hemoglobin molecule can bind 4 oxygen molecules ▪ Each erythrocyte has 250 million hemoglobin molecules ▪ Normal blood contains 12–18 g of hemoglobin per 100 milliliters (ml) of blood © 2018 Pearson Education, Ltd.  Formed Elements ▪ Homeostatic imbalance of RBCs ▪ Anemia is a decrease in the oxygen-carrying ability of the blood due to: ▪ Lower-than-normal number of RBCs ▪ Abnormal or deficient hemoglobin content in the RBCs ▪ Sickle cell anemia (SCA) results from abnormally shaped hemoglobin © 2018 Pearson Education, Ltd. Homeostatic Imbalance 10.1 Comparison of (a) a normal erythrocyte to (b) a sickled erythrocyte (6,550×). 2 3 7...146 2 3 7...146 1 1 4 6 4 6 5 5 (a) Normal RBC and part of the (b) Sickled RBC and part of its amino acid sequence of its hemoglobin sequence hemoglobin © 2018 Pearson Education, Ltd.  Formed Elements ▪ Polcythemia ▪ Disorder resulting from excessive or abnormal increase of RBCs due to: ▪ Bone marrow cancer (polycythemia vera) ▪ Life at higher altitudes (secondary polycythemia) ▪ Increase in RBCs slows blood flow and increases blood viscosity © 2018 Pearson Education, Ltd.  Formed Elements ▪ Leukocytes (white blood cells, or WBCs) ▪ Crucial in body’s defense against disease ▪ Complete cells, with nucleus and organelles ▪ Able to move into and out of blood vessels (diapedesis) ▪ Respond to chemicals released by damaged tissues (known as positive chemotaxis) ▪ Move by amoeboid motion ▪ 4,800 to 10,800 WBCs per mm3 of blood © 2018 Pearson Education, Ltd.  Formed Elements ▪ Leukocytosis ▪ WBC count above 11,000 cells per mm3 of blood ▪ Generally indicates an infection ▪ Leukopenia ▪ Abnormally low WBC count ▪ Commonly caused by certain drugs, such as corticosteroids and anticancer agents ▪ Leukemia ▪ Bone marrow becomes cancerous ▪ Numerous immature WBC are produced © 2018 Pearson Education, Ltd.  Formed Elements ▪ Types of leukocytes ▪ Granulocytes ▪ Granules in their cytoplasm can be stained ▪ Possess lobed nuclei ▪ Include neutrophils, eosinophils, and basophils ▪ Agranulocytes ▪ Lack visible cytoplasmic granules ▪ Nuclei are spherical, oval, or kidney-shaped ▪ Include lymphocytes and monocytes © 2018 Pearson Education, Ltd.  Formed Elements ▪ List of the WBCs, from ▪ Easy way to remember most to least abundant this list ▪ Neutrophils ▪ Never ▪ Lymphocytes ▪ Let ▪ Monocytes ▪ Monkeys ▪ Eosinophils ▪ Eat ▪ Basophils ▪ Bananas © 2018 Pearson Education, Ltd.  Formed Elements ▪ Platelets ▪ Fragments of megakaryocytes (multinucleate cells) ▪ Needed for the clotting process ▪ Normal platelet count is 300,000 platelets per mm3 of blood © 2018 Pearson Education, Ltd. Table 10.2 Characteristics of Formed Elements of the Blood (1 of 3) © 2018 Pearson Education, Ltd. Table 10.2 Characteristics of Formed Elements of the Blood (2 of 3) © 2018 Pearson Education, Ltd. Table 10.2 Characteristics of Formed Elements of the Blood (3 of 3) © 2018 Pearson Education, Ltd.  Hematopoiesis (Blood Cell Formation) ▪ Hematopoiesis is the process of blood cell formation ▪ Occurs in red bone marrow (myeloid tissue) ▪ All blood cells are derived from a common stem cell (hemocytoblast) ▪ Hemocytoblasts form two types of descendants ▪ Lymphoid stem cell, which produces lymphocytes ▪ Myeloid stem cell, which can produce all other formed elements © 2018 Pearson Education, Ltd. Figure 10.3 The development of blood cells. Hemocytoblast stem cells Lymphoid Myeloid stem cells stem cells Secondary stem cells Basophils Erythrocytes Platelets Eosinophils Lymphocytes Monocytes Neutrophils © 2018 Pearson Education, Ltd.  Formation of Red Blood Cells ▪ Since RBCs are anucleate, they are unable to divide, grow, or synthesize proteins ▪ RBCs wear out in 100 to 120 days ▪ When worn out, RBCs are eliminated by phagocytes in the spleen or liver ▪ Lost cells are replaced by division of hemocytoblasts in the red bone marrow © 2018 Pearson Education, Ltd.  Formation of Red Blood Cells ▪ Rate of RBC production is controlled by a hormone called erythropoietin ▪ Kidneys produce most erythropoietin as a response to reduced oxygen levels in the blood ▪ Homeostasis is maintained by negative feedback from blood oxygen levels © 2018 Pearson Education, Ltd. Figure 10.4 Mechanism for regulating the rate of RBC production. Slide 1 Homeostasis: Normal blood oxygen levels 1 Stimulus 5 O2–carrying Low blood O2–carrying ability ability of blood due to increases. Decreased RBC count Decreased amount of hemoglobin Decreased availability of O2 4 Enhanced erythropoiesis 2 Kidneys (and liver, increases RBC to a smaller extent) count. release erythropoietin. 3 Erythropoietin stimulates red bone marrow. © 2018 Pearson Education, Ltd. Figure 10.4 Mechanism for regulating the rate of RBC production. Slide 2 Homeostasis: Normal blood oxygen levels 1 Stimulus Low blood O2–carrying ability due to Decreased RBC count Decreased amount of hemoglobin Decreased availability of O2 © 2018 Pearson Education, Ltd. Figure 10.4 Mechanism for regulating the rate of RBC production. Slide 3 Homeostasis: Normal blood oxygen levels 1 Stimulus Low blood O2–carrying ability due to Decreased RBC count Decreased amount of hemoglobin Decreased availability of O2 2 Kidneys (and liver, to a smaller extent) release erythropoietin. © 2018 Pearson Education, Ltd. Figure 10.4 Mechanism for regulating the rate of RBC production. Slide 4 Homeostasis: Normal blood oxygen levels 1 Stimulus Low blood O2–carrying ability due to Decreased RBC count Decreased amount of hemoglobin Decreased availability of O2 2 Kidneys (and liver, to a smaller extent) release erythropoietin. 3 Erythropoietin stimulates red bone marrow. © 2018 Pearson Education, Ltd. Figure 10.4 Mechanism for regulating the rate of RBC production. Slide 5 Homeostasis: Normal blood oxygen levels 1 Stimulus Low blood O2–carrying ability due to Decreased RBC count Decreased amount of hemoglobin Decreased availability of O2 4 Enhanced erythropoiesis 2 Kidneys (and liver, increases RBC to a smaller extent) count. release erythropoietin. 3 Erythropoietin stimulates red bone marrow. © 2018 Pearson Education, Ltd. Figure 10.4 Mechanism for regulating the rate of RBC production. Slide 6 Homeostasis: Normal blood oxygen levels 1 Stimulus 5 O2–carrying Low blood O2–carrying ability ability of blood due to increases. Decreased RBC count Decreased amount of hemoglobin Decreased availability of O2 4 Enhanced erythropoiesis 2 Kidneys (and liver, increases RBC to a smaller extent) count. release erythropoietin. 3 Erythropoietin stimulates red bone marrow. © 2018 Pearson Education, Ltd.  Hemostasis ▪ Hemostasis is the process of stopping the bleeding that results from a break in a blood vessel ▪ Hemostasis involves three phases 1. Vascular spasms 2. Platelet plug formation 3. Coagulation (blood clotting) © 2018 Pearson Education, Ltd.  Hemostasis ▪ Step 1: vascular spasms ▪ Immediate response to blood vessel injury ▪ Vasoconstriction causes blood vessel to spasm ▪ Spasms narrow the blood vessel, decreasing blood loss © 2018 Pearson Education, Ltd. Figure 10.5 Events of hemostasis. Slide 2 Step 1 Vascular spasms occur. Smooth muscle contracts, causing vasoconstriction. © 2018 Pearson Education, Ltd.  Hemostasis ▪ Step 2: platelet plug formation ▪ Collagen fibers are exposed by a break in a blood vessel ▪ Platelets become “sticky” and cling to fibers ▪ Anchored platelets release chemicals to attract more platelets ▪ Platelets pile up to form a platelet plug (white thrombus) © 2018 Pearson Education, Ltd. Figure 10.5 Events of hemostasis. Slide 3 Step 2 Platelet plug forms. Injury to lining of vessel exposes collagen fibers; platelets adhere. Collagen fibers Platelets release chemicals that make nearby platelets sticky; platelet plug forms. Platelets © 2018 Pearson Education, Ltd. Figure 10.5 Events of hemostasis. Slide 4 Step 3 Coagulation events occur. Clotting factors present in plasma and released by injured tissue cells interact with Ca2+ to form thrombin, the enzyme that catalyzes joining of Fibrin fibrinogen molecules in plasma to fibrin. Fibrin forms a mesh that traps red blood cells and platelets, forming the clot. © 2018 Pearson Education, Ltd. Figure 10.6 Fibrin clot. Blood usually clots within 3 to 6 minutes The clot remains as endothelium regenerates The clot is broken down after tissue repair © 2018 Pearson Education, Ltd.  Disorders of Hemostasis ▪ Undesirable clotting ▪ Thrombus ▪ A clot in an unbroken blood vessel ▪ Can be deadly in areas such as the lungs ▪ Embolus ▪ A thrombus that breaks away and floats freely in the bloodstream ▪ Can later clog vessels in critical areas such as the brain © 2018 Pearson Education, Ltd.  Disorders of Hemostasis ▪ Bleeding disorders ▪ Thrombocytopenia ▪ Insufficient number of circulating platelets ▪ Arises from any condition that suppresses the bone marrow ▪ Even normal movements can cause bleeding from small blood vessels that require platelets for clotting ▪ Evidenced by petechiae (small purplish blotches on the skin) © 2018 Pearson Education, Ltd.  Disorders of Hemostasis ▪ Bleeding disorders (continued) ▪ Hemophilia ▪ Hereditary bleeding disorder ▪ Normal clotting factors are missing ▪ Minor tissue damage can cause life-threatening prolonged bleeding © 2018 Pearson Education, Ltd.  Blood Groups and Transfusions ▪ Large losses of blood have serious consequences ▪ Loss of 15 to 30 percent causes weakness ▪ Loss of over 30 percent causes shock, which can be fatal ▪ Blood transfusions are given for substantial blood loss, to treat severe anemia, or for thrombocytopenia © 2018 Pearson Education, Ltd.  Human Blood Groups ▪ Blood contains genetically determined proteins known as antigens ▪ Antigens are substances that the body recognizes as foreign and that the immune system may attack ▪ Most antigens are foreign proteins ▪ We tolerate our own “self” antigens ▪ Antibodies are the “recognizers” that bind foreign antigens ▪ Blood is “typed” by using antibodies that will cause blood with certain proteins to clump (agglutination) and lyse © 2018 Pearson Education, Ltd.  Human Blood Groups ▪ There are over 30 common red blood cell antigens ▪ The most vigorous transfusion reactions are caused by ABO and Rh blood group antigens © 2018 Pearson Education, Ltd.  Human Blood Groups ▪ ABO blood group ▪ Blood types are based on the presence or absence of two antigens 1. Type A 2. Type B ▪ ABO blood group ▪ Presence of both antigens A and B is called type AB ▪ Presence of antigen A is called type A ▪ Presence of antigen B is called type B ▪ Lack of both antigens A and B is called type O © 2018 Pearson Education, Ltd.  Human Blood Groups ▪ ABO blood group (continued) ▪ Type AB can receive A, B, AB, and O blood ▪ Type AB is the “universal recipient” ▪ Type B can receive B and O blood ▪ Type A can receive A and O blood ▪ Type O can receive O blood ▪ Type O is the “universal donor” © 2018 Pearson Education, Ltd. Table 10.3 ABO Blood Groups (1 of 2) © 2018 Pearson Education, Ltd. Table 10.3 ABO Blood Groups (2 of 2) © 2018 Pearson Education, Ltd.  Human Blood Groups ▪ Rh blood group ▪ Named for the eight Rh antigens (agglutinogen D) ▪ Most Americans are Rh+ (Rh-positive), meaning they carry the Rh antigen ▪ If an Rh–(Rh-negative) person receives Rh+ blood: ▪ The immune system becomes sensitized and begins producing antibodies; hemolysis does not occur, because as it takes time to produce antibodies ▪ Second, and subsequent, transfusions involve antibodies attacking donor’s Rh+ RBCs, and hemolysis occurs (rupture of RBCs) © 2018 Pearson Education, Ltd.  Human Blood Groups ▪ Rh-related problem during pregnancy ▪ Danger occurs only when the mother is Rh–, the father is Rh+, and the child inherits the Rh+ factor ▪ RhoGAM shot can prevent buildup of anti-Rh+ antibodies in mother’s blood © 2018 Pearson Education, Ltd.  Human Blood Groups ▪ 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) © 2018 Pearson Education, Ltd.  Blood Typing ▪ Blood samples are mixed with anti-A and anti-B serum ▪ Agglutination or the lack of agglutination leads to identification of blood type ▪ Typing for ABO and Rh factors is done in the same manner ▪ Cross matching—testing for agglutination of donor RBCs by the recipient’s serum, and vice versa © 2018 Pearson Education, Ltd. Figure 10.7 Blood typing of ABO blood groups. Blood being tested Serum Anti-A 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) © 2018 Pearson Education, Ltd.