The Cardiovascular System: The Blood Chapter 18 Lecture Notes

1
The Cardiovascular System The BloodChapter 18
Lecture Notes

• to accompany
• Anatomy and Physiology From Science to Life
• textbook by
• Gail Jenkins, Christopher Kemnitz, Gerard Tortora

2
Chapter Overview

• 18.1 Blood Anatomy and Physiology
• 18.2 Hemopoiesis
• 18.3 Mature Red Blood Cells
• 18.4 RBC Life Cycle
• 18.5 Erythropoiesis
• 18.6 Blood Groups
• 18.7 White Blood Cells
• 18.8 Platelets
• 18.9 Hemostasis

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Essential Terms

• plasma
• liquid portion of blood
• formed elements
• cells and cell fragments of blood
• RBC
• red blood cell
• WBC
• white blood cells or leukocytes
• hemopoiesis
• blood cell production
• pluripotent stem cell
• cells with capacity to develop into several types
  of cells

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Introduction

• Cardiovascular system consists of three
  interrelated components
• blood
• heart
• blood vessels
• Blood is connective tissue with liquid portion
  (plasma) and cell and cell fragments portion
  (formed elements)
• RBCs carry oxygen
• WBCs function in immunity

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Concept 18.1Anatomy and Physiology of Blood
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Functions of Blood

• Transportation
• oxygen from lungs to body tissues
• metabolic wastes from tissues to lungs, kidneys,
  and liver
• nutrients from GI tract to body cells
• hormones
• Regulation
• pH via buffers
• body temperature
• Protection
• blood loss
• immunity and immune responses

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Physical Characteristics of Blood

• more viscous than water
• temperature about 1 degree celcius higher than
  oral or rectal body temperature
• alkaline pH (7.35 to 7.45)
• 8 of total body weight
• 5-6 L in adult male
• 4-5 L in adult female

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Components of Blood

• 45 formed elements
• 99 are RBCs
• 1 WBCs and platelets
• 55 blood plasma

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Figure 18.1a
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Figure 18.1b
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Blood Plasma

• 91.5 water
• 7 proteins
• synthesized mainly by hepatocytes
• most plentiful is albumin 54 of all proteins
• helps maintain blood osmotic pressure
• globulins 38 of all proteins
• antibodies or immunoglobulins
• fibrinogen 7 of all proteins
• key component of blood clots
• 1.5 solutes other than proteins
• electrolytes, nutrients, gases, regulatory
  substances, vitamins, and waste products

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Table 18.1 pt 1
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Table 18.1 pt 2
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Formed Elements

• Living cells
• RBCs
• WBC
• neutrophils, lymphocytes, monocytes, eosinophils,
  basophils
• Cell Fragments
• platelets
• Hematocrit
• relative percent of RBCs to total blood volume

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Formed Elements

• Erythropoietin
• hormone that stimulates RBC production
• anemia abnormally low hematocrit
• polycythemia abnormally high hematocrit

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Concept 18.2 Hemopoiesis
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Hemopoiesis

• process by which formed elements develop
• before birth occurs in liver, spleen, thymus,
  lymph nodes of fetus
• last trimester and beyond occurs in red bone
  marrow
• red bone marrow found in spaces between
  trabeculae of spongy bone
• 0.05-0.1 of red bone marrow are pluripotent stem
  cells

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Figure 18.3
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Concept 18.3 Mature Red Blood Cells
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Erythrocytes

• contain hemoglobin
• adult males have 5.4 million RBCs per
  microliter of whole blood
• adult females have 4.8 million RBCs per
  microliter of whole blood
• one drop of blood is 50 microliters
• mature blood cells leave marrow at rate of 2
  million per second
• same rate they are destroyed

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RBC Anatomy

• biconcave on disks
• 8 microliters diameter
• lack a nucleus and other organelles
• cannot reproduce
• essentially consist of a plasma membrane,
  cytosol, and hemoglobin
• each contains about 280 million hemoglobin
  molecules
• lack mitochondria

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Figure 18.4a
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Figure 18.4b
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Figure 18.4c
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RBC Physiology

• all internal space is available for oxygen
  transport
• generate ATP anaerobically
• dont use any oxygen
• hemoglobin
• globin (protein) pigment protein called heme
  with iron ion in center where oxygen is
  transported
• also transports about 13 of total carbon dioxide

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Concept 18.4 RBC Life Cycle
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Figure 18.5
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Concept 18.5 Erythropoiesis
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Erythropoiesis

• production of RBCs
• proerythroblast divides and develops to eject
  nucleus becoming a reticulocyte
• only 34 hemoglobin
• contain some mitochondria
• ribosomes and endoplasmic reticulum
• usually develop into erythrocytes within 1 to 2
  days after release for bone marrow

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Figure 18.6
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Concept 18.6 Blood Groups
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ABO Blood Groups

• Antigen A on RBCs of people with type A blood
• anti B antibody in plasma
• Antigen B on blood cells of people with type B
  blood
• anti A antibody in plasma
• Antigen A and Antigen B on RBCs of people with
  type AB blood
• neither antibody in plasma
• Neither antigen is on RBCs of people with type O
  blood
• anti A and anti B antibodies in plasma

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Figure 18.7
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Rh Blood Group

• antigen first discovered in blood of rhesus
  monkey
• Rh have antigen
• Rh- do not have antigen
• no anti Rh antibodies until exposed to Rh blood

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Table 18.2
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Transfusions

• whole blood
• blood components
• RBCs
• plasma
• if incompatible the antigens causing hemolysis of
  donated cells and to a much lesser extent
  hemolysis of recipients RBCs (type A and B only)

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Table 18.3
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Concept 18.7 White Blood Cells
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WBCs or Leukocytes

• have a nucleus and do not contain hemoglobin
• either granular or agranular
• granular
• neutrophils, eosinophils, basophils
• agranular
• lymphocytes, monocytes

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Figure 18.3
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Granular Leukocytes

• eosinophils
• combat effects of histamine and other
  inflammatory and allergic responses
• phagocytize antigen-antibody complexes and some
  parasitic worms
• basophils
• release heparin, histamine, and serotonin
• intensifying inflammatory response
• involved in hypersensitivity (allergic) reactions
• neutrophils
• antibiotic activity against bacteria and fungi
• release lysozyme, strong oxidants, and defensins

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Agranular Leukocytes

• monocytes
• develop into macrophages and phagocytize microbes
• clean up cellular debris following an infection
• lymphocytes
• B cells
• differentiate into cells that produce antibodies
• T cells
• attack viruses, fungi, transplanted cells,
  cancers, some bacteria, some allergic reactions
• natural killer cells
• attack wide variety of infectious microbes and
  certain spontaneously arising tumor cells

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WBC Life Span

• most live only a few days
• during infection some live only a few hours
• some B and T cells can live for years
• differential WBC count
• can distinguish between viral, bacterial,
  parasitic infections, allergies

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Table 18.4
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Concept 18.8 Platelets
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Platelets

• also known as thrombocytes
• fragment of a megakaryoblast
• fragments into 2000-3000 parts and then leave
  marrow to enter blood
• between 150,000-400,000 per each 1 microliter of
  blood
• function to stop bleeding by forming a plug

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Table 18.5
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Concept 18.9 Hemostasis
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Hemostasis

• sequence of responses that stops bleeding
• must be quick, localized, and carefully
  controlled
• vascular spasm
• smooth muscle contracts immediately after damage
• platelet plug formation
• Fig. 18.10
• blood clotting
• Fig. 18.11 and 18.12

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Fig. 18.10 pt 1
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Fig. 18.10 pt 2
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Fig. 18.10 pt 3
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Fig. 18.11a
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Fig. 18.11b
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Fig. 18.11c
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Fig. 18.11d
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Fig. 18.12
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Extrinsic Pathway

• clotting occurs rapidly
• within seconds if trauma severe
• tissue factor leaked into blood from outside
  blood vessels
• eventually converted to prothrombinase
• uses calcium

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Intrinsic Pathway

• occurs slowly
• usually requires several minutes
• activators in direct contact with blood or
  contained within blood
• outside tissue damage not needed
• uses calcium ions

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Common Pathway

• prothrombinase is formed
• together with calcium ions converted to thrombin
• thrombin converts fibrinogen to loose fibrin
  threads (insoluble) and stablizes them into
  sturdy clot
• positive feedback cycle

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Fig. 18.12
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Clot Retraction

• tightening of fibrin clot
• platelets contract pulling edges of damaged
  vessel closer together
• decreasing risk of further damage
• fibroblasts begin forming connective tissue over
  ruptured area
• new endothelial cells arise and vessel lining is
  repaired

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End Chapter 18