Download - Chapter 19, part 1

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

Fundamentals of

Anatomy & PhysiologySIXTH EDITION

Frederic H

. Martini

PowerPoint® Lecture Slide Presentation prepared by Dr. Kathleen A. Ireland, Biology Instructor, Seabury Hall, Maui, Hawaii

Chapter 19, part 1

Blood


Learning Objectives

• List the components of the cardiovascular system and explain the major functions of this system.

• Describe the important components and major functions of the blood

• List the characteristics and functions of red blood cells.

• Describe the structure of hemoglobin and indicate its functions.

• Discuss red blood cell production and maturation.


Learning Objectives

• Explain the importance of blood typing and the basis for ABO and Rh incompatibilities.

• Categorize the various white blood cells on the basis of structure and function.

• Describe the structure, function and production of platelets.

• Describe the reaction sequences responsible for blood clotting.


SECTION 19-1 The Cardiovascular System: An Introduction


• Provides a mechanism for rapid transport of nutrients, waste products, respiratory gases and cells

The cardiovascular system


SECTION 19-2Functions and Composition of Blood


• Fluid connective tissue

• Functions include

• Transporting dissolved gases, nutrients, hormones, and metabolic wastes

• Regulating pH and ion composition of interstitial fluids

• Restricting fluid loss at injury sites

• Defending the body against toxins and pathogens

• Regulating body temperature by absorbing and redistributing heat

Blood


The composition of blood

• Plasma and formed elements comprise whole blood

• Red blood cells (RBC)

• White blood cells (WBC)

• Platelets

• Can fractionate whole blood for analytical or clinical purposes

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 19.1a

Figure 19.1 The Composition of Whole Blood


• Process of blood cell formation

• Hemocytoblasts are circulating stem cells that divide to form all types of blood cells

• Whole blood from anywhere in the body has roughly the same temperature, pH and viscosity

Hemopoiesis


SECTION 19-3Plasma


• Accounts for 46-63% of blood volume

• 92% of plasma is water

• Higher concentration of dissolved oxygen and dissolved proteins than interstitial fluid

Plasma


• more than 90% are synthesized in the liver

• Albumins

• 60% of plasma proteins

• Responsible for viscosity and osmotic pressure of blood

Plasma proteins


• Globulins

• ~35% of plasma proteins

• Include immunoglobins which attack foreign proteins and pathogens

• Include transport globulins which bind ions, hormones and other compounds

• Fibrinogen

• Converted to fibrin during clotting

• Removal of fibrinogen leaves serum

Additional Plasma Proteins


SECTION 19-4Red Blood Cells


• Erythrocytes account for slightly less than half the blood volume, and 99.9% of the formed elements

• Hematocrit measures the percentage of whole blood occupied by formed elements

• Commonly referred to as the volume of packed red cells

Abundance of RBCs


• Biconcave disc, providing a large surface to volume ration

• Shape allows RBCs to stack, bend and flex

• RBCs lack organelles

• Typically degenerate in about 120 days.

Structure of RBCs

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 19.2

Figure 19.2 The Anatomy of Red Blood Cells


• Molecules of hemoglobin account for 95% of the proteins in RBCs

• Hemoglobin is a globular protein, formed from two pairs of polypeptide subunits

• Each subunit contains a molecule of heme which reversibly binds an oxygen molecule

• Damaged or dead RBCs are recycled by phagocytes

Hemoglobin


Figure 19.3 The Structure of Hemoglobin


Figure 19.4 “Sickling” in Red Blood Cells


• Replaced at a rate of approximately 3 million new blood cells entering the circulation per second.

• Replaced before they hemolyze

• Components of hemoglobin individually recycled

• Heme stripped of iron and converted to biliverdin, then bilirubin

• Iron is recycled by being stored in phagocytes, or transported throughout the blood stream bound to transferrin

RBC life span and circulation


Figure 19.5 Red Blood Cell Turnover


• Erythropoeisis = the formation of new red blood cells

• Occurs in red bone marrow

• Process speeds up with in the presence of EPO (Erythropoeisis stimulating hormone)

• RBCs pass through reticulocyte and erythroblast stages

RBC Production


Figure 19.6 Stages of RBC Maturation


• Determined by the presence or absence of surface antigens (agglutinogens)

• Antigens A, B and Rh (D)

• Antibodies in the plasma (agglutinins)

• Cross-reactions occur when antigens meet antibodies

Blood types


Figure 19.8 Blood Typing and Cross-Reactions


Figure 19.9 Blood Type Testing


Figure 19.10 Rh Factors and Pregnancy


SECTION 19-5The White Blood Cells


• Have nuclei and other organelles

• Defend the body against pathogens

• Remove toxins, wastes, and abnormal or damaged cells

• Are capable of amoeboid movement (margination) and positive chemotaxis

• Some are capable of phagocytosis

Leukocytes


• Granular leukocytes

• Neutrophils – 50 to 70 % total WBC population

• Eosinophils – phagocytes attracted to foreign compounds that have reacted with antibodies

• Basophils – migrate to damaged tissue and release histamine and heparin

Types of WBC


• Agranular leukocytes

• Monocytes - become macrophage

• Lymphocytes – includes T cells, B cells, and NK cells

Types of WBC


Figure 19.11 White Blood Cells


• Indicates a number of disorders

• Leukemia = inordinate number of leukocytes

Differential count


• Granulocytes and monocytes are produced by bone marrow stem cells

• Divide to create progenitor cells

• Stem cells may originate in bone marrow and migrate to peripheral tissues

• Several colony stimulating factors are involved in regulation and control of production

WBC Production


Figure 19.12 The Origins and Differentiation of Formed Elements

Animation: The origins and differentiation of blood cells PLAY


SECTION 19-6Platelets


• Flattened discs

• Circulate for 9-12 days before being removed by phagocytes

Platelets


• Transporting chemicals important to clotting

• Forming temporary patch in walls of damaged blood vessels

• Contracting after a clot has formed

Platelet functions


• Megakaryocytes release platelets into circulating blood

• Rate of platelet formation is stimulated by thrombopoietin, thrombocyte-stimulating factor, interleukin-6, and Multi-CSF

Platelet production (thrombocytopoiesis)


SECTION 19-7Hemostasis


Hemostasis

• Prevents the loss of blood through vessel walls

• Three phases –

• Vascular phase

• Platelet phase

• Coagulation phase


Hemostasis

• Vascular phase

• Local blood vessel constriction (vascular spasm)

• Platelet phase

• Platelets are activated, aggregate at the site, adhere to the damaged surfaces


Figure 19.13 The Vascular and Platelet Phases of Hemostasis


Coagulation phase

• Factors released by platelets and endothelial cells interact with clotting factors to form a clot

• Extrinsic pathway

• Intrinsic pathway

• Common pathway

• Suspended fibrinogen is converted to large insoluble fibrin fibers


Clot retraction

• Final phase of healing

• Platelets contract and pull the edges of the vessel together


Fibrinolysis

• Clot gradually dissolves through action of plasmin

• Activated form of plasminogen

• Clotting can be prevented through the use of drugs that depress the clotting response or dissolve existing clots

• Anticoagulants include heparin, coumadin, aspirin, dicumarol, t- PA, streptokinase, and urokinase


You should now be familiar with:

• The components of the cardiovascular system and its major functions.

• The important components and major functions of the blood.

• The characteristics and functions of red blood cells.

• The structure of hemoglobin and its functions.

• Red blood cell production and maturation.


You should now be familiar with:

• The importance of blood typing and the basis for ABO and Rh incompatibilities.

• The various white blood cells.

• The structure, function and production of platelets.

• The reaction sequences responsible for blood clotting.