Anatomy and Physiology Sixth Edition Rod R Seeley

Anatomy and Physiology, Sixth Edition Rod R. Seeley Idaho State University Trent D. Stephens Idaho State University Philip Tate Phoenix College Chapter 19 Lecture Outline* *See Power. Point Image Slides for all figures and tables pre-inserted into Power. Point without notes. 19 -1 Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display.

Chapter 19 Cardiovascular System Blood 19 -2

Functions of Blood • Transport of: – Gases, nutrients, waste products – Processed molecules – Regulatory molecules • • Regulation of p. H and osmosis Maintenance of body temperature Protection against foreign substances Clot formation 19 -3

Composition of Blood 19 -4

Plasma • Liquid part of blood – Pale yellow made up of 91% water, 9% other • Colloid: Liquid containing suspended substances that don’t settle out – Albumin: Important in regulation of water movement between tissues and blood – Globulins: Immune system or transport molecules – Fibrinogen: Responsible formation of blood clots 19 -5

Formed Elements • Red blood cells (erythrocytes) • White blood cells (leukocytes) – Granulocytes • Neutrophils • Eosinophils • Basophils – Agranulocytes • Lymphocytes • Monocytes • Platelets (thrombocytes) 19 -6

Production of Formed Elements • Hematopoiesis or hemopoiesis: Process of blood cell production • Stem cells: All formed elements derived from single population – Proerythroblasts: Develop into red blood cells – Myeloblasts: Develop into basophils, neutrophils, eosinophils – Lymphoblasts: Develop into lymphocytes – Monoblasts: Develop into monocytes – Megakaryoblasts: Develop into platelets 19 -7

Hematopoiesis 19 -8

Erythrocytes • Structure – Biconcave, anucleate • Components – Hemoglobin – Lipids, ATP, carbonic anhydrase • Function – Transport oxygen from lungs to tissues and carbon dioxide from tissues to lungs 19 -9

Hemoglobin • Consists of: – 4 globin molecules: Transport carbon dioxide (carbonic anhydrase involved), nitric oxide – 4 heme molecules: Transport oxygen • Iron is required for oxygen transport 19 -10

Erythropoiesis • Production of red blood cells – Stem cells proerythroblasts early erythroblasts intermediate late reticulocytes • Erythropoietin: Hormone to stimulate RBC production 19 -11

Hemoglobin Breakdown 19 -12

Leukocytes • Types • Protect body against microorganisms and remove dead cells and debris • Movements – Ameboid – Diapedesis – Chemotaxis – Neutrophils: Small phagocytic cells – Eosinophils: Reduce inflammation – Basophils: Release histamine and increase inflammatory response – Lymphocytes: Immunity – Monocytes: Become macrophages 19 -13

Leukocytes

• Five Types of White Blood Cells and Their Functions – There are two different types of white blood cells and each looks different from one another under the microscope. – These include granulocytes and agranulocytes.

• Granulocytes have visible granules or grains inside the cells that have different cell functions. – Types of granulocytes include basophils, neutrophils, and eosinophils. • Agranulocytes are free of visible grains under the microscope and include lymphocytes and monocytes

• Together, they coordinate with one another to fight off things like cancer, cellular damage, and infectious diseases.

• Neutrophils – Neutrophils are the most common type of white blood cell in the body with levels of between 2000 to 7500 cells per mm 3 in the bloodstream. – Neutrophils are medium-sized white blood cells with irregular nuclei and many granules that perform various functions within the cell. • Function: Neutrophils function by attaching to the walls of the blood vessels, blocking the passageway of germs that try to gain access to the blood through a cut or infectious area

• Neutrophils are the first cells to reach an area where a breach in the body has been made. • They kill germs by means of a process known as phagocytosis or “cell-eating”. • Besides eating bacteria one-by-one, they also release a burst of super oxides that have the ability to kill many bacteria at the same time.

• Lymphocytes – Lymphocytes are small, round cells that have a large nucleus within a small amount of cytoplasm. – They have an important function in the immune system, being major players in the humoral immune system, which is the part of the immune system that relates to antibody production. – Lymphocytes tend to take up residence in lymphatic tissues, including the spleen, tonsils, and lymph nodes. – There about 1300 to 4000 lymphocytes per mm 3 of blood.

• Function: – B lymphocytes make antibodies, which is one of the final steps in disease resistance. – When B lymphocytes make antibodies, they prime pathogens for destruction and then make memory cells ready that can go into action at any time, remembering a previous infection with a specific pathogen. – T lymphocytes are another type of lymphocyte, differentiated in the thymus and important in cellmediated immunity.

• Monocytes – Monocytes are the largest of the types of white blood cells. – There are only about 200 -800 monocytes per mm 3 of blood. – Monocytes are agranulocytes, meaning they have few granules in the cytoplasm when seen under the microscope. – Monocytes turn into macrophages when they exit the bloodstream.

• Function: – As macrophages, monocytes do the job of phagocytosis (cell-eating) of any type of dead cell in the body, whether it is a somatic cell or a dead neutrophil. – Because of their large size, they have the ability to digest large foreign particles in a wound unlike other types of white blood cells.

• Eosinophils – There aren’t that many eosinophils in the bloodstream—only about 40 -400 cells per mm 3 of blood. – They have large granules that help in cellular functions. – Eosinophils are especially important when it comes to allergies and worm infestations.

• Function: – Eosinophils work by releasing toxins from their granules to kill pathogens. – The main pathogens eosinophils act against are parasites and worms. – High eosinophil counts are associated with allergic reactions.

• Basophils – Basophils are the least frequent type of white blood cell, with only 0 -100 cells per mm 3 of blood. – Basophils have large granules that perform functions that are not well known. – They are very colorful when stained and looked at under the microscope, making them easy to identify.

• Function: – Basophils have the ability to secrete anticoagulants and antibodies that have function against hypersensitivity reactions in the bloodstream. – They act immediately as part of the immune system’s action against foreign invaders. – Basophils contain histamine, which dilates the vessels to bring more immune cells to the area of injury.

• Macrophages: - are the main phagocytes of the body. • Neutrophils: - are the first responders and become phagocytic when they encounter infectious material.

• Eosinophils: - are weakly phagocytic but are important in defending the body against parasitic worms. • Mast cells: - have the ability to bind with, ingest, and kill a wide range of bacteria.

Natural killer cells • They are able to lyse and kill : - cancer cells - virally infected cells before the adaptive immune system has been activated

Leukocytes 19 -32

Thrombocytes • Cell fragments pinched off from megakaryocytes in red bone marrow • Important in preventing blood loss – Platelet plugs – Promoting formation and contraction of clots 19 -33

Hemostasis • Arrest of bleeding • Events preventing excessive blood loss – Vascular spasm: Vasoconstriction of damaged blood vessels – Platelet plug formation – Coagulation or blood clotting 19 -34

Platelet Plug Formation 19 -35

Coagulation • Stages – Activation of prothrombinase – Conversion of prothrombin to thrombin – Conversion of fibrinogen to fibrin • Pathways – Extrinsic – Intrinsic 19 -36

Clot Formation 19 -37

Fibrinolysis • Clot dissolved by activity of plasmin, an enzyme which hydrolyzes fibrin 19 -38

Blood Grouping • Determined by antigens (agglutinogens) on surface of RBCs • Antibodies (agglutinins) can bind to RBC antigens, resulting in agglutination (clumping) or hemolysis (rupture) of RBCs • Groups – ABO and Rh 19 -39

ABO Blood Groups 19 -40

Agglutination Reaction 19 -41

Rh Blood Group • First studied in rhesus monkeys • Types – Rh positive: Have these antigens present on surface of RBCs – Rh negative: Do not have these antigens present • Hemolytic disease of the newborn (HDN) – Mother produces anti-Rh antibodies that cross placenta and cause agglutination and hemolysis of fetal RBCs 19 -42

Erythroblastosis Fetalis 19 -43

Diagnostic Blood Tests • Type and crossmatch • Complete blood count – Red blood count – Hemoglobin measurement – Hematocrit measurement • White blood count • Differential white blood count • Clotting 19 -44

Blood Disorders • Erythrocytosis: RBC overabundance • Anemia: Deficiency of hemoglobin – – – Iron-deficiency Pernicious Hemorrhagic Hemolytic Sickle-cell • • • Hemophilia Thrombocytopenia Leukemia Septicemia Malaria Infectious mononucleosis • Hepatitis 19 -45