Chapter 11 The Cardiovascular System: Blood

Chapter 11 The Cardiovascular System: Blood
Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Topics Introduction The Functions of Blood The Composition of Blood
Plasma Formed Elements Platelets Homeostasis Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Introduction Body is in constant chemical communication with outside environment Nutrients absorbed through the lining of the digestive tract Gases move across thin epithelium of the lungs Wastes excreted in the feces and urine Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Introduction Chemical exchanges occur at specialized sites
Affect every cell, tissue, and organ in moments All body parts linked by cardiovascular system Transport network Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Introduction Contains: Circulating fluid Pump
Flexible tubing to carry the fluid Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Introduction Develops when simple diffusion cannot meet the demands of the developing embryo Provides a rapid-transport system Oxygen Nutrients Waste products Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Introduction First organ system to become fully operational
Heart begins beating by the end of the third week of embryonic development Begins to circulate blood Facilitates embryonic growth Can double in size in the next week Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

The Functions of Blood Blood is the circulating fluid of the body
Specialized connective tissue Contains cells suspended in a fluid matrix 5 major functions Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

The Functions of Blood 5 major functions
Transportation of dissolved gases, nutrients, hormones, and metabolic wastes Regulation of the pH and ion composition of interstitial fluids throughout the body Restriction of fluid losses at injury sites Defense against toxins and pathogens Stabilization of body temperature Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

The Functions of Blood Transportation of dissolved gases, nutrients, hormones, and metabolic wastes Carries oxygen from the lungs to the tissues Carries carbon dioxide from the tissues to the lungs Distributes nutrients Absorbed through digestive tract Released from storage in adipose tissue or the liver Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

The Functions of Blood Transportation of dissolved gases, nutrients, hormones, and metabolic wastes Carries hormones from endocrine glands toward target cells Absorbs waste products produced by active cells Carries wastes to kidneys for excretion Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

The Functions of Blood Regulation of the pH and ion composition of interstitial fluids throughout the body Diffusion with interstitial fluids Eliminates deficiencies or excesses of ions Example: Calcium and potassium Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

The Functions of Blood Regulation of the pH and ion composition of interstitial fluids throughout the body Absorbs and neutralizes acids generated by active tissues Example: Lactic acid produced by skeletal muscle contractions Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

The Functions of Blood Restriction of fluid losses at injury sites
Contains enzymes and factors that respond to breaks in vessel walls Initiates the clotting process Clot acts as a temporary patch to prevent further blood loss Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

The Functions of Blood Defense against toxins and pathogens
Transports white blood cells Specialized cells Migrate into body tissues to fight infections and remove debris Delivers antibodies Special proteins Attack invading organisms or foreign compounds Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

The Functions of Blood Stabilization of body temperature
Absorbs heat generated by active skeletal muscles Redistributes it to other tissues Directed to the skin surface to promote heat loss Restricts flow to the brain and temperature-sensitive organs to conserve heat Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

The Composition of Blood

White blood cells Leukocytes Less numerous Part of the body’s defense mechanisms Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Platelets Small Membrane-enclosed packets of cytoplasm Contain enzymes and factors important to blood clotting Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Whole blood All formed elements and plasma May be separated or fractionated for analytical or clinical purposes Volume 5–6 liters in adult males 4–5 liters in adult females Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Blood collection and analysis Whole blood usually collected from a superficial vein Procedure referred to as venipuncture Veins easy to locate Walls are thin Under low pressure Puncture wounds seal quickly Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Blood collection and analysis Peripheral capillary blood Obtained through skin puncture Tip of finger Ear lobe Great toe or heel in infants Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Blood collection and analysis Capillary blood Used to prepare a blood smear Thin film of blood on a microscopic slide Stained with special dyes to show different formed elements Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Blood collection and analysis Arterial puncture Used to evaluate the efficiency of gas exchange in the lungs Usually drawn from the radial or brachial artery Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Blood collection and analysis Whole blood characteristics Temperature Roughly 38ºC Viscosity 5 times as viscous as water Results from interactions among dissolved proteins, formed elements, and water pH Slightly alkaline, between 7.35–7.45 Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Plasma Makes up roughly 55% of whole blood volume
92% of plasma is water Combines with interstitial fluid to account for most extracellular volume Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Plasma Composition Resembles interstitial fluid (IF)
Concentrations of major ions similar to IF Differ from concentrations inside cells Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Plasma Composition Constant exchange of water, ions, and small solutes
Occurs through capillary walls Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Plasma Composition Differences from IF
Concentration of dissolved proteins Plasma proteins too large to cross capillary walls Levels of respiratory gases Due to respiratory activities of cells Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Plasma Plasma proteins Considerable quantities of dissolved proteins
7 g in 100 ml of plasma 5 times interstitial composition Remain confined to circulatory system Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Plasma Plasma proteins 3 primary types: Albumins Globulins Fibrinogen

Plasma Albumins Constitute 60% of all plasma proteins
Major contributor to osmotic pressure Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Plasma Globulins Constitute 35% of plasma proteins
Includes antibodies and transport proteins Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Plasma Globulins Antibodies Also called immunoglobulins
Attack foreign proteins and pathogens Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Plasma Globulins Transport proteins Bind small ions Hormones Compounds
Might be lost at the kidneys Have a very low solubility in water Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Plasma Albumins and globulins Can bind to lipids
Triglycerides, fatty acids, or cholesterol Not water soluble Protein-lipid combination dissolves readily in plasma Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Plasma Cardiovascular system
Transports insoluble lipids to peripheral tissues Lipid transporting globulins referred to as lipoproteins Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Plasma Fibrinogen Functions in blood clotting
Interact and convert to form large, insoluble strands Referred to as fibrin Fibrin provides the basic framework for a blood clot Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Plasma Fibrinogen Plasma samples Clotting must be prevented in samples
Serum Fluid that remains after clotting proteins removed Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Plasma Liver Synthesizes more than 90% of plasma proteins
All albumins and fibrinogen Most globulins Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Plasma Liver disorders
Alter the composition and functional properties of blood Example: Uncontrollable bleeding Inadequate synthesis of fibrinogen and other plasma proteins Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Plasma Antibodies Produced by plasma cells of lymphatic system

Formed Elements Red blood cells White blood cells Platelets
Most abundant White blood cells Platelets Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements The production of formed elements
Hemopoiesis or hematopoiesis Process that produces formed elements Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Embryonic blood cells Appear during the third week of development Divide repeatedly to increase in number Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Embryonic blood cells Yolk sac Embryonic membrane Primary site of blood formation for first 8 weeks Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Embryonic organ system development Some embryonic blood cells move out of the bloodstream Move into the liver, spleen, thymus, and bone marrow Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Pluripotent stem cells Hemocytoblasts Divide to produce Myeloid stem cells Lymphoid stem cells Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Pluripotent stem cells Retain the ability to divide Daughter cells produce specific types of blood cells Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Primary site of hemopoiesis Liver and spleen Second to fifth month of development Red bone marrow in adults Only site of red blood cell production Primary site of white blood cell formation Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Red blood cells Contain the pigment hemoglobin
Binds and transports oxygen and carbon dioxide Most abundant cells Account for 99.9% of formed elements Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Red blood cell count Reported as RBCs per microliter
Roughly 5.4 million Single drop contains roughly 260 million Constitutes about one-third of the 75 trillion cells in the human body Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Hematocrit
Percentage of whole blood occupied by cellular elements Measured after whole blood is spun in a centrifuge Pulls formed elements out of suspension Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Hematocrit Gender differences
Males 40–54%; females 37–47% Androgens stimulate RBC production Estrogens do not Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Hematocrit Closely approximates the volume of RBCs
1000 RBCs for each WBC Reported as volume of packed red cells (VPRC) Packed cell volume (PCV) Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Conditions affecting hematocrit Increase Dehydration
Reduction in plasma volume Erythropoietin stimulation Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Conditions affecting hematocrit Decrease
Internal bleeding Problems with RBC formation Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Conditions affecting hematocrit
Variations from normal levels Do not provide specific diagnostic information Indication for more specific tests Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements The structure of RBCs
Specialized to transport oxygen and carbon dioxide in the blood Biconcave disc Thin central region Thick outer margin Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Shape has 2 important functional effects Creates a large surface area to volume ratio Increases the rate of diffusion between cytoplasm and plasma Enables bending and flexing to squeeze through narrow capillaries Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Lose most organelles during formation Ribosomes and nuclei Do not undergo cell division Do not synthesize structural proteins or enzymes Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements The structure of RBCs Mitochondrial loss
Only obtains energy through anaerobic metabolism Relies on glucose obtained from surrounding plasma Inefficient energy use Absorbed oxygen carried to peripheral tissue Not utilized by mitochondria in cytoplasm Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Hemoglobin structure and function Mature cells
Cell membrane Enclosed mass of transport proteins Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Hemoglobin structure and function
Hemoglobin molecules (Hb) Account for 95% of RBC’s intracellular proteins Responsible for ability to transport oxygen and carbon dioxide Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed from 2 pairs of globular proteins Each pair composed of slightly different polypeptide chains Each subunit contains a single molecule of heme Organic pigment Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Hemoglobin structure and function Heme molecule
Holds iron ion Allows interaction with oxygen molecule Iron-oxygen interaction Very weak Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Hemoglobin bound with oxygen Bright red color Hemoglobin without oxygen Dark red, almost burgundy color Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

When oxygen is abundant in plasma Hemoglobin gains oxygen until all heme molecules are occupied Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

When plasma oxygen levels decline Carbon dioxide levels usually rise Hemoglobin molecules release oxygen reserves Globin portion of hemoglobin molecule binds carbon dioxide Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Circulating RBCs exposed to varying concentrations of oxygen and carbon dioxide Lungs Diffusion brings oxygen into plasma and removes carbon dioxide Hemoglobin molecules absorb oxygen and release carbon dioxide Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Hemoglobin structure and function Peripheral tissues
Active cells consume oxygen and produce carbon dioxide Oxygen diffuses out of plasma and carbon dioxide diffuses in Hemoglobin releases bound oxygen and bonds carbon dioxide Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Anemia Blood has a low hematocrit
RBCs have reduced hemoglobin content Results in reduced oxygen carrying capacity Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Anemia Variety of symptoms Premature muscle fatigue
Weakness General lack of energy Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements RBC life span and circulation
Round-trip through circulatory system takes less than 1 minute Exposed to severe physical stress Forced through vessels Bounces off vessel walls Collides with other RBCs Squeezed through tiny capillaries Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements RBC life span and circulation No repair mechanisms
Short life span Approximately 120 days New cells enter system at comparable rate 1% replaced each day 3 million per second Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Hemoglobin recycling RBCs may rupture when damaged
Hemoglobin breaks down in the blood Individual polypeptide chains filtered in the kidneys Excreted in the urine Only 10% Referred to as hemolysis Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Hemoglobin recycling Hemoglobinuria
Large quantities of RBCs break down in bloodstream Urine turns reddish or brown Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Hemoglobin recycling Normal breakdown
Phagocytic cells recognize and engulf RBCs before hemolysis Occurs in liver, spleen, and bone marrow Recycle hemoglobin and other components Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Hemoglobin recycling RBC engulfed by macrophage
Broken down Each component has a different fate Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Hemoglobin recycling Globular proteins
Disassembled into component amino acids Metabolized by the cell Released into circulation for use by other cells Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Hemoglobin recycling Heme molecules Stripped of iron
Converted to biliverdin Organic compound with a green color Cause of discoloration with bruises Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Hemoglobin recycling Heme molecules
Biliverdin converted to bilirubin Orange-yellow pigment Released into circulation Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Hemoglobin recycling Heme molecules
Bilirubin absorbed by liver cells Released into the small intestine within the bile Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Hemoglobin recycling Jaundice
Caused when bile ducts are blocked Bilirubin diffuses into peripheral tissues Causes a yellowing of the skin and sclera Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Hemoglobin recycling
Bilirubin reaching large intestine Converted to related pigment molecules May be absorbed into the bloodstream Excreted into the urine Pigments cause yellow urine and brown feces Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Hemoglobin recycling Iron from heme molecules
Stored in the macrophage Released into the bloodstream Binds to transferrin Plasma transports protein Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

New red blood cells develop in the bone marrow Absorb amino acids and transferrins from circulation Used in the synthesis of new hemoglobin molecules Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Hemoglobin recycling Excess transferrins
Removed in the liver and spleen Iron stored in special protein-iron complexes Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Most components recycled following hemolysis or phagocytosis Efficient system 26 mg iron utilized daily 1–2 mg required through diet to replace incidental losses Excretion through feces or urine Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Impaired iron uptake or metabolism Serious clinical problems associated with RBC formation Women have smaller reserves Results in iron deficiency anemia Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Hemoglobin recycling Excess iron accumulation
Linked to heart disease Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Red blood cell formation Erythropoiesis
Occurs in red bone marrow or myeloid tissue Located in the vertebrae, sternum, ribs, scapulae, pelvis, and proximal limb bones Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Red blood cell formation Yellow bone marrow
Fatty tissue contained in other bones Can be converted to red marrow under extreme stimulation Severe and sustained blood loss Increases the rate of RBC formation Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Stages in RBC maturation Hematologists
Specialists in blood formation and function Named key stages in the maturation of formed elements Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Stages in RBC maturation
RBCs result from the division of hemocytoblasts Pluripotent stem cells in red bone marrow Produce myeloid stem cells Proceed through stages to become mature erythrocytes Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Stages in RBC maturation Erythroblasts
Immature red blood cells Actively synthesize hemoglobin Undergo 4 days of differentiation Shed nucleus to become a reticulocyte Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Stages in RBC maturation Reticulocytes
Spend 2–3 more days in red bone marrow Synthesize proteins Enter the bloodstream Can be detected in a blood smear with stains that combine with RNA Account for 0.8% of circulating erythrocytes Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Stages in RBC maturation Reticulocytes
Complete maturation after 24 hours in circulation Become indistinguishable from mature RBCs Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements The regulation of erythropoiesis
Red bone marrow must receive adequate supplies Amino acids, iron, and vitamins Includes B12, B6, and folic acid Requires for protein synthesis Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements The regulation of erythropoiesis Vitamin B12
Obtained from dairy products and meats Absorption requires the presence of intrinsic factor Produced in the stomach Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Vitamin B12 deficiency Normal stem cell divisions cannot occur Results in pernicious anemia Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Stimulated directly by the hormone erythropoietin Indirect hormonal stimulation Thyroxine, androgens, and growth hormone Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Erythropoietin
Also called erythropoiesis-stimulating hormone Appears in plasma when peripheral tissues exposed to low oxygen concentrations Especially the kidneys Referred to as hypoxia Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Erythropoietin release During anemia
When blood flow to the kidneys declines When oxygen content of the air in the lungs declines When respiratory surfaces of the lung are damaged Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Erythropoietin Released into the bloodstream
Travels to red bone marrow Stimulates stem cells and developing RBCs Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Erythropoietin 2 major effects
Stimulates increased cell division rates in erythroblasts Also in stem cells that produce erythroblasts Speeds up the maturation of red blood cells Primarily accelerates hemoglobin synthesis Can increase formation 10 times Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Erythropoietin and RBC production

Formed Elements Erythropoietin Administration to healthy individuals
Hematocrit may rise above 65 Increased blood viscosity increase workload on the heart May lead to sudden death from heart failure Similar effects from blood doping Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements RBCs and blood types Antigens Surface antigens
Substances that can trigger an immune response Defense mechanism to protect the body from infection Surface antigens Present on all cells Recognized as normal by immune defenses Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements RBCs and blood types 50 kinds of surface antigens
Genetically determined Presence or absence of 3 antigens determines blood type A, B, Rh Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements RBCs and blood types
All RBCs in an individual have the same pattern of surface antigens Type A has antigen A only Type B has antigen B only Type AB has both antigen A and B Type O has neither antigen A nor B Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements RBCs and blood types

Formed Elements RBCs and blood types Population Type O: 46%
Type A: 40% Type B: 10% Type AB: 4 % Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements RBCs and blood types Rh antigen
Rh positive indicates antigen presence Rh negative indicates antigen absence Rh term typically eliminated from naming of blood type Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Antibodies Surface antigens
Referred to as agglutinations Ignored by immune system Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Antibodies Plasma Contains antibodies
Referred to as agglutinins Attack surface antigens on different types of red blood cells Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Plasma antibodies
Type A blood contains circulating anti-B antibodies Attack Type B surface antigens Type B blood contains anti-A antibodies Attack Type A surface antigens Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Plasma antibodies
Type AB blood lacks both anti-A and anti-B antibodies Type O blood contains both anti-A and anti-B antibodies Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Antibodies and cross-reactions Antibodies
Reason for blood types of donors and recipients to be matched prior to transfusion If different blood types transfused Antibodies in plasma meet the specific antigen on donated RBCs Results in a cross-reaction Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Cross-reactions Antigens and antibodies bind
Cause foreign RBCs to clump together Referred to as agglutination Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Cross-reactions Clumped RBCs may hemolyze
Creates clumps and fragments of RBCs under attack from antibodies Form drifting masses Plug small vessels in kidneys, lungs, heart, and brain Damage or destroy tissues Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Cross-reactions Transfusion reactions
Avoided by ensuring compatibility of donor and recipient blood Surface antigens on donor cells more important than antibodies in donor plasma Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Cross-reactions
Between donor plasma and recipient blood cells Significant agglutination only occurs with large volume of whole blood Donor plasma diluted with large plasma volume of recipient Commonly transfuse packed RBCs Contain minimal amounts of plasma Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Antibodies and cross-reactions Rh negative individuals
Does not normally contain anti-Rh antibodies Only present if sensitized by previous exposure to Rh positive RBCs Example: Normal pregnancy where Rh negative mother carries Rh positive fetus Accidental exposure during transfusion Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements White blood cells WBCs or leukocytes
Differences from RBCs Larger size Nucleus and other organelles present Lack hemoglobin Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements White blood cells
Defend the body against pathogen invasion Remove toxins, wastes, and abnormal or damaged cells Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements White blood cells Divided into 2 groups
Based on appearance after staining Granulocytes Abundant stained granules Agranulocytes Few, if any, stained granules Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements White blood cells Granules
Secretory vesicles and lysosomes Also present in agranulocytes Smaller and more difficult to see with a light microscope Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements White blood cells Granulocytes Neutrophils Eosinophils
Basophils Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements White blood cells Agranulocytes Monocytes Lymphocytes

Formed Elements White blood cells
Circulating cells make up small portion of total population Most located in connective tissue or lymphatic system Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements WBC circulation and movement
Circulate for only a short portion of life span Migrate through loose and dense connective tissues Use bloodstream to travel between organs Rapid transport to areas of invasion or injury Sensitive to chemical signs of damage to surrounding tissues Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements WBC circulation and movement 4 characteristics
Capable of amoeboid movement Can migrate out of the bloodstream Attracted to specific chemical stimuli Some are capable of phagocytosis Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Capable of amoeboid movement Gliding motion Caused by flow of cytoplasm into slender cellular processes Extend out from the cell Allows WBCs to move along vessel walls and through surrounding tissue Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Migration out of the bloodstream Squeeze between adjacent epithelial cells in capillary wall Process referred to as diapedesis Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Attraction to specific chemical stimuli Referred to as positive chemotaxis Guides WBCs to invading pathogens, damaged tissues, and other WBCs Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Neutrophils, eosinophils, and monocytes capable of phagocytosis Engulf pathogens, cell debris, or other materials Neutrophils and eosinophils may be referred to as microphages Distinguish them from macrophages Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements WBC circulation and movement Macrophages Monocytes
Moved out of the blood stream Actively phagocytic Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Types of WBCs
Neutrophils, eosinophils, basophils, and monocytes Contribute to the body’s nonspecific defenses Respond to a variety of stimuli in the same way Do not discriminate between types of threats Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Types of WBCs Lymphocytes
Responsible for specific defenses Attack pathogens and proteins on specific, individual basis Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Neutrophils Account for 50–70% of circulating WBCs
Granules are chemically neutral Difficult to stain with acidic or basic dyes Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Neutrophils Very dense, contorted nucleus 2 to 5 lobes
Resemble beads on a string Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Neutrophils
Typically the first WBC to arrive at an injury site Very active phagocytes Specialize in attacking and digesting bacteria Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Neutrophils Short life span About 10 hours
Engulf 1–2 dozen bacteria, and then die Breakdown releases chemicals Attracts other neutrophils to the site Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Neutrophils Pus Associated with infected wounds
Mixture of dead neutrophils, cellular debris, and other waste products Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Eosinophils Granules stain darkly with red dye eosin
Represent 2–4% of circulating WBCs Similar in size to neutrophils Deep red granules and two-lobed nucleus Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Eosinophils Attack objects coated with antibodies
Will engulf any antibody-marked bacteria, protozoa, or cellular debris Primary mode of attack is exocytosis of toxic compounds Includes nitric oxide and cytotoxic enzymes Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Eosinophils Dramatic increase in quantity
Parasitic infections Allergic reactions Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Basophils
Numerous granules that stain darkly with basic dyes Deep purple or blue in a standard blood smear Smaller than neutrophils or eosinophils Account for less than 1% of circulating WBC population Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Basophils Migrate to sites of injury
Cross capillary wall to accumulate within damaged tissues Discharge granules into interstitial fluid Release other chemicals to attract more eosinophils and basophils to the area Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Basophils Granules contain: Heparin Histamine
Prevents blood clotting Histamine Enhances local inflammation initiated by mast cells in damaged tissues Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Monocytes
Nearly twice the size of a typical erythrocyte Large oval- or kidney-shaped nucleus Account for 2–8% of circulating WBCs Remain in circulation for about 24 hours Enter peripheral tissue to become macrophages Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Monocytes
Migrating monocytes referred to as free macrophages Distinguished from fixed macrophages Present in many connective tissues Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Monocytes Aggressive phagocytes
Often engulf items of the same size or larger Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Monocytes Chemical release
Attracts and stimulates neutrophils, additional monocytes, and other phagocytes Draws fibroblasts to the region Begin to produce scar tissue to separate the region Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Lymphocytes Slightly larger than RBCs
Contain a relatively large nucleus Surrounded by a thin halo of cytoplasm Continuously migrate from the bloodstream into peripheral tissues Very small fraction of circulating WBC population Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Lymphocytes Protect the body and its tissues
Do not rely on phagocytosis Some attack foreign and abnormal cells Some secrete antibodies into circulation Antibodies attack foreign cells or proteins in distant regions Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements The differential count and changes in WBC abundance
Refers to the number of each type of cell in a sample of 100 WBCs Obtained by examining a stained blood smear Characteristic changes result from infections, inflammation, and allergic reactions Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Leukopenia indicates a reduced quantity of WBCs Leukocytosis refers to an excessive number of WBCs Extreme leukocytosis usually indicative of leukemia Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements Leukemia Cancer of blood-forming tissues
Some types characterized by leukocytosis May have the presence of abnormal or immature WBCs Treatment helpful in some cases All cases fatal if not treated Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements White blood cell formation Hemocytoblasts
Responsible for the development of all formed elements Present in red bone marrow Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements White blood cell formation Hemocytoblasts Produce:
Lymphoid stem cells Give rise to lymphocytes Myeloid stem cells Give rise to all other types of formed elements Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements White blood cell formation
Basophils, eosinophils, and neutrophils Complete development in myeloid tissue Monocytes Begin differentiation in bone marrow Enter the circulation Complete development when they become free macrophages Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements White blood cell formation Lymphoid stem cells
Many migrate from the bone marrow to peripheral lymphoid tissues Includes the thymus, spleen, and lymph nodes Lymphocytes produced in organs and bone marrow Lymphopoiesis refers to the process of lymphocyte production Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Hormones regulate WBC population All WBCs except lymphocytes Regulated by colony-stimulating factors (CSFs) Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements White blood cell formation 4 identified CSFs
Each targets a single stem cell line or a group of stem cell lines Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements White blood cell formation Differentiation of T cells
1 type of lymphocyte Promoted by thymosins produced by the thymus gland Occurs prior to an individual reaching maturity Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Formed Elements White blood cell formation Adult lymphocyte production
Regulated by exposure to antigens Includes foreign proteins, cells, and toxins Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Lymphocyte hormones affect the production of other WBCs Active macrophages Release chemicals making lymphocytes more sensitive to antigens Accelerates the development of specific immunity Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Active lymphocytes release CSFs Reinforce nonspecific defenses Stimulate the production of other WBCs Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Platelets Component of formed elements
Cell fragments rather than individual cells Major component of the vascular clotting system Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Platelets Megakaryocytes Enormous cells with large nuclei
Found in bone marrow Continuously shed cytoplasm into small membrane-enclosed packets Packets are the platelets that enter the bloodstream Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Platelets Continuously replaced Circulate for 9–12 days
Removed by phagocytes 150,000–500,000 in each microliter of blood Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Platelets Low platelet count Less than 80,000 per microliter
Referred to thrombocytopenia Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Platelets Thrombocytopenia Excessive platelet destruction
Inadequate platelet production Clinical signs include bleeding May occur along digestive tract, within the skin, or inside the CNS Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Platelets Thrombocytosis Platelet count exceeds 1,000,000
Results from accelerated platelet formation Response to infection, inflammation, or cancer Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Homeostasis The process that halts bleeding
Prevents the loss of blood through the walls of damaged vessels Establishes framework for tissue repairs Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Homeostasis Consists of 3 overlapping phases Vascular phase
Platelet phase Coagulation phase Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Homeostasis Phase 1: Vascular phase Vascular spasm
Local contraction triggered by cutting the wall of a blood vessel Decreases the vessel’s diameter Can slow or stop the loss of blood Lasts about 30 minutes Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Homeostasis Phase 1: Vascular phase
Changes occur in the vessel’s endothelium Inner lining of simple squamous epithelium Membranes of endothelial cells become “sticky” May stick together in capillaries, causing a complete occlusion Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Homeostasis Phase 2: Platelet phase
Platelets attach to sticky endothelial surfaces and exposed collagen fibers Begins within 15 seconds of the injury Attachments mark the start of the platelet phase More platelets arrive and attach to each other Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Homeostasis Phase 2: Platelet phase Formation of a platelet plug
Mass of platelets that may close the break in the vessel wall Especially if the damage is not severe, or occurs in a small vessel Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Homeostasis Phase 3: Coagulation phase
Does not start for more than 30 seconds after vessel is damaged Coagulation Blood clotting Complex sequence of steps Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Homeostasis Phase 3: Coagulation phase Coagulation
Converts circulating fibrinogen to an insoluble protein fibrin Fibrin network begins to grow Blood cells and platelets trapped in fibrous tangle Forms a blood clot Effectively seals off the damaged portion of the vessel Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Homeostasis The clotting process
Normal clotting requires the presence of necessary clotting factors in plasma Includes calcium ions and 11 different plasma proteins Proteins converted from inactive proenzymes Become active enzymes that direct essential reactions in clotting process Most are synthesized in the liver Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Homeostasis The clotting process
Clotting proteins interact in sequence Occurs during the coagulation phase Creates a cascade 1 protein is converted into an enzyme The enzyme then activates a second protein Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Homeostasis The clotting process 3 pathways for blood clot formation
Extrinsic pathway begins outside the bloodstream, in the vessel wall Intrinsic pathway begins inside the bloodstream Common pathway is the joining of the 2 other pathways Occurs through the activation of Factor X Clotting protein produced by the liver Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Homeostasis The extrinsic, intrinsic, and common pathways
Extrinsic and intrinsic pathways activated when the vessel is damaged Clotting begins within 15 seconds Initiated by the extrinsic pathway Shorter and faster Intrinsic pathway reinforces the initial clot Makes it larger and more effective Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Homeostasis Extrinsic pathway Begins with the release of tissue factor
Lipoprotein Released by damaged endothelial cells or peripheral tissues The greater the damage, the more tissue factor released Clotting occurs faster Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Homeostasis Extrinsic pathway Tissue factor
Combines with calcium ions and Factor VII Another clotting protein Forms an enzyme capable of activating Factor X Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Homeostasis Intrinsic pathway
Begins with the activation of proenzymes exposed to collagen fibers Occurs at the injury site Proceeds with the assistance of platelet factor Released by aggregating platelets Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Homeostasis Intrinsic pathway
Platelets release a variety of other factors Speed up the reactions of the intrinsic pathway Linked reactions occur Activated clotting proteins combine Form an enzyme capable of activating Factor X Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Homeostasis Common pathway Begins with the activation of Factor X
Can be initiated by enzymes of either the extrinsic or intrinsic pathway Activated Factor X forms the enzyme prothrombinase Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Homeostasis Common pathway Prothrombinase
Converts the clotting protein prothrombin into the enzyme thrombin Thrombin completes the clotting process Convert fibrinogen to fibrin Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Homeostasis Thrombin Acts to increase the rate of clot formation
Stimulates the formation of tissue factor Stimulates the release of platelet factor by platelets These factors then further stimulate the other pathways Creates a positive feedback loop Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Homeostasis Clot retraction and removal Fibrin network appears
Platelets and red blood cells stick to fibrin strands Platelets contract Pulls the torn edges of the wound closer together Clot undergoes clot retraction Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Homeostasis Clot retraction Reduces the size of the damaged area
Makes it easier for repairs Fibroblasts, smooth muscle cells, and endothelial cells Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Homeostasis Fibrinolysis Clot gradually dissolves as repairs proceed
Begins with the activation of plasminogen Plasma protein Activated by thrombin and tissue plasminogen activator (t-PA) t-PA released by damaged tissues Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Homeostasis Fibrinolysis Plasmin
Enzyme produced through the activation of plasminogen Begins digesting fibrin strands Slowly breaks down the clot Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Summary Describe the components and functions of blood, plasma, and platelets Understand the origin and formation of the formed elements Understand the characteristics and functions of red and white blood cells Understand how blood loss is reduced following an injury Bledsoe et al., Anatomy & Physiology for Emergency Care, 2nd Ed. © 2008 by Pearson Education, Inc. Upper Saddle River, NJ

Chapter 11 The Cardiovascular System: Blood

Similar presentations

Presentation on theme: "Chapter 11 The Cardiovascular System: Blood"— Presentation transcript:

Similar presentations

About project

Feedback

Log in

Auth with social network:

Chapter 11 The Cardiovascular System: Blood

Similar presentations

Presentation on theme: "Chapter 11 The Cardiovascular System: Blood"— Presentation transcript:

Similar presentations

About project

Feedback