Download Chapter Twenty One

Chapter 21
*Lecture Outline
*See separate FlexArt PowerPoint slides for all
figures and tables pre-inserted into PowerPoint
without notes.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Chapter 21 Outline
• General Composition and Functions of
Blood
• Blood Plasma
• Formed Elements in the Blood
• Hemopoiesis: Production of Formed
Elements
Introduction
Blood serves many functions. Some examples are:
• Transportation of oxygen and carbon dioxide as
well as nutrients and waste products
• Regulation of body temperature, pH, and fluid
volume
• Protection by mounting an immune response
and the production of antibodies
Composition of Blood
Figure 21.1
Composition of Blood
Upon separation by centrifugation, blood
has three factions:
1. Erythrocytes—represent ~ 44% of total
blood volume
2. Buffy coat—represents about 1% of total
blood volume
3. Plasma—represents ~ 55% of total blood
volume
Composition of Blood
Figure 21.2
Blood Smear
Figure 21.3
Blood Plasma
Formed Elements
• The hematocrit is the % of the volume of
all formed elements in one’s blood
• It varies in females from 38%–46% and
between 42%–56% in males
Erythrocytes
• Also referred to as red blood cells or
RBCs, but this is a misnomer as mature
RBCs lack nuclei and other organelles
Figure 21.4
Erythrocytes
• Relatively small (7.5 μm in diameter)
• Unique biconcave shape
• As they pass through small blood vessels,
they line up in single file termed a rouleau
Hemoglobin in Erythrocytes
•
•
•
Every erythrocyte contains 280 million
molecules of a red-pigmented protein called
hemoglobin
Hemoglobin is capable of reversibly
transporting oxygen and carbon dioxide in the
blood
Hemoglobin consists of four globin protein
molecules:
1.
2.
Two alpha (α) chains
Two beta (ß) chains
Molecular Structure of Hemoglobin
Figure 21.5
Hemoglobin
• Each of the four globins possesses a
nonprotein heme group containing an iron
(Fe2+) molecule.
• Each hemoglobin molecule can bind a
combination of four oxygen/carbon dioxide
molecules.
Recycling the Components of Aged
or Damaged Erythrocytes
Figure 21.6
Blood Type
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
ABO Blood Types
Antigen A
Antigen B
Antigens A and B
Neither antigen
A nor B
Erythrocytes
Anti-B antibodies
Anti-A antibodies
Neither anti-A nor
anti-B antibodies
Both anti-A and
anti-B antibodies
Plasma
Blood type
Type A
Erythrocytes with
type A surface
antigens and plasma
with anti-B antibodies
Type B
Erythrocytes with
type B surface
antigens and plasma
with anti-A antibodies
(a)
Rh Blood Types
Antigen D
No antigen D
Erythrocytes
No anti-D antibodies
Anti-D antibodies
(after prior exposure)
Rh positive
Erythrocytes with
type D surface
antigens and plasma
with no anti-D
antibodies
Rh negative
Erythrocytes with no
type D surface
antigens and plasma
with anti-D antibodies,
only if there has been
prior exposure to Rh
positive blood
Plasma
Blood type
Figure 21.7
(b)
Type AB
Erythrocytes with
both type A and
type B surface
antigens, and plasma
with neither anti-A
nor anti-B antibodies
Type O
Erythrocytes with
neither type A nor
type B surface
antigens, but plasma
with both anti-A and
anti-B antibodies
Agglutination Reaction
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
+
Donor blood type
=
Recipient blood type
Agglutination reaction
Antigen A
+
Type A blood of donor
(has surface antigenA)
=
Type A blood of recipient
(contains anti-B antibodies)
Antigen and
antibody
do not match
No clumping seen.
Successful blood type match.
No agglutination
Antigen A
+
Type A blood of donor
(has surface antigenA)
=
Type B blood of recipient
(contains anti-A antibodies)
Antigen and
antibody match
and connect
Agglutination
Clumping seen.
Hemolysis occurs.
Unsuccessful blood type match.
(a) Agglutination test
Type B recipient erythrocyte
Blood from type A donor
Anti-A antibody in recipient plasma
Type A donor erythrocyte
Agglutinated erythrocytes
from type A donor block
small vessels
Figure 21.8
(b) Erythrocyte agglutination
a: © Jean Claude Revy-ISM/Phototake
Leukocytes
• Unlike erythrocytes, leukocytes possess a
nucleus and organelles.
• They help initiate an immune response and
defend the body against pathogens.
• They are 1.5 to 3 times larger than erythrocytes.
• They are capable of leaving the blood vessels,
diapedesis, and entering a tissue.
• Leukocytes are attracted to a site of infection by
molecules from damaged cells or invading
pathogens. This attraction is called chemotaxis.
Classification of Leukocytes
• The five types of leukocytes are divided
into two classes (granulocytes and
agranulocytes) based on the presence or
absence of visible organelles termed
granules.
Leukocytes
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Table 21.3
Leukocytes
LM 1600x
Eosinophil
LM 1600x
LM 1600x
Neutrophil
Basophil
Granulocytes
Agranulocytes
LM 1600x
LM 1600x
Lymphocyte
Type
GRANULOCYTES
Monocyte
Characteristics
Functions
Approximate %
Neutrophils
Nucleus is multilobed (as many as five lobes)
Cytoplasm contains neutral or pale, distinct
granules (when stained)
Phagocytize pathogens, especially bacteria
Release enzymes that target pathogens
50–70% of total leukocytes
Eosinophils
Nucleus is bilobed
Phagocytize antigen-antibody complexes and
allergens
1–4% of total leukocytes
Cytoplasm contains reddish or pink-orange
granules (when stained)
Basophils
Nucleus is bilobed
Cytoplasm contains deep blue-violet granules
(when stained)
Release chemical mediators to destroy parasitic
worms
Release histamine (vasodilator) and heparin
(anticoagulant) during inflammatory or allergic
reactions
0.5–1% of total leukocytes
AGRANULOCYTES
Lymphocytes
Round or slightly indented nucleus (fills the
cell in smaller lymphocytes)
Nucleus is usually darkly stained
Thin rim of cytoplasm surrounds nucleus
Attack pathogens and abnormal/infected cells
Coordinate immune cell activity
Produce antibodies
20–40% of total leukocytes
Monocytes
Kidney-shaped or C-shaped nucleus
Nucleus is generally pale staining
Abundant cytoplasm around nucleus
Can exit blood vessels and become
macrophages Phagocytize pathogens,
cellular debris, dead cells
2–8% of total leukocytes
Platelets
• Irregular membrane-enclosed cellular fragments
that represent shed cytoplasm from cells in the
red bone marrow called megakaryocytes
• Megakaryocytes are about 15× larger than
erythrocytes
• Platelets are about ¼ the size of erythrocytes
• Platelets are involved in the clotting of blood
Platelets and Megakaryocytes
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Red bone
marrow
Megakaryocyte
Megakaryocytes
LM 1600x
Endothelial cells
(a)
(b)
a: © The McGraw-Hill Companies, Inc./Photo by Dr. Alvin Telser
Figure 21.9
Proplatelets
Platelets
Blood Clot
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Fibrin
Platelets
Erythrocytes
SEM 4100x
Reprinted by permission from Macmillan Publishers Ltd: Nature, Dr. John W. Weisel and Yuri Veklich. Vol. 413, Issue 4, Cover
Image, October 2001. © 2001 Nature Publishing Group
Figure 21.10
Hemopoiesis
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Hemocytoblast
(blood stem cell)
Lymphoid line
Myeloid line
Myeloid stem cell
Multi-CSF
Lymphoid stem cell
Multi-CSF
Multi-CSF
Erythropoiesis
Progenitor cell
Thrombopoiesis
Leukopoiesis
Progenitor cell
B-lymphoblast
GM-CSF
T-lymphoblast
Progenitor cell
Proerythroblast
Megakaryoblast
Myeloblast
M-CSF
Monoblast
EPO
Early erythroblast
Thrombopoietin
G-CSF
Promegakaryocyte
Promyelocytes
Late
erythroblast
M-CSF
Promonocyte
Thrombopoietin
Normoblast
Megakaryocyte
Eosinophilic
myelocyte
Basophilic
myelocyte
Neutrophilic
myelocyte
Eosinophil
Basophil
Neutrophil
Nucleus
ejected
Reticulocyte
Erythrocyte
Thrombopoietin
Platelets
Figure 21.11
Monocyte
B-lymphocyte
T-lymphocyte
Erythropoiesis
• Erythropoiesis is the process of
erythrocyte production.
• About 3 million erythrocytes are produced
per second.
• During maturation all organelles within the
erythrocyte, including the nucleus,
degenerate leaving the erythrocyte with
nothing more than a “bag of hemoglobin.”