Transcript blood cells

Human Biology Concepts and Current Issues
Seventh Edition
Michael D. Johnson
7
Blood
© 2014 Pearson Education, Inc.
Lecture Presentations by
Robert J. Sullivan
Marist College
OBJECTIVES
•Describe the function of blood
•List and describe the components of blood and plasma
•Describe the source and function of specific blood cells
•Interpret the results of a blood tests
•Describe the purpose, factors, and stages of
hemostasis
• Identify human blood types and their interaction
• Illustrate examples of homeostasis
•Describe various blood disorders
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From Cells to Organ Systems
Cell
(blood cells)
Tissue
(vascular)
Organ
(heart)
Organ System
(circulatory system)
Organism
(human)
Stepped Art
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Fig. 19-2, p. 389
Circulatory System Overview
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Consists of heart (pump),blood vessels, and blood
Picks up nutrients from digestive system
Exchanges gases with respiratory system
Delivers nutrients and O2 to every cell
Carries CO2 to lungs for removal
Carries wastes and excess water to urinary system
Carries metabolic wastes to liver for removal
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Figure 7.1
Oxygen
intake
Food and
water intake
Elimination of
carbon dioxide
The Human Body
Respiratory
system
O2
CO2
Nutrients,
salt, water
Digestive
system
Water, salts,
metabolic waste
Circulatory
system
Urinary
system
Metabolic
waste
Transport
to and from
all cells
Elimination of
food residues,
metabolic wastes
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Elimination of
excess water, salts,
metabolic wastes
The Components and Functions of Blood
 Blood is a specialized connective tissue.
 Three primary functions:
1. Transportation of nutrients, waste, hormones
2. Regulation of body temperature, pH
3. Defense against infections and bleeding
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© 2014 Pearson Education, Inc.
Animation: Blood
Right-click and select Play
The Components and Functions of Blood
 Plasma (makes up 55% of whole blood)
–
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–
–
–
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Water
Electrolytes
Proteins (albumins, globulins, clotting proteins)
Hormones
Gases
Nutrients and wastes
 Formed elements (makes up 45% of whole blood)
– RBCs
– WBCs
– Platelets
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Plasma: 55% in whole blood
Hematocrit: the percentage RBC in whole blood; almost
45%
Plasma (55%)
Whole
blood
Platelets and
WBC (1%)
RBC (44%)
Whole blood.
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Blood after being
spun in centrifuge.
A table-top centrifuge.
Plasma Consists of Water and Dissolved Solutes
 Plasma: liquid portion of the blood
 90% water
 10% dissolved solutes
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–
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–
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Proteins
Hormones
Ions
Nutrients: amino acids, glucose, fatty acids
Metabolic wastes
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Plasma Consists of Water and Dissolved Solutes
 Plasma proteins
– Albumins: maintain osmotic balance in blood
– Globulins: diverse group of proteins
– Carrier proteins- transport functions
– Example bind to lipids, some hormones
– Gamma globulins: antibodies which are part of the
body’s defenses against infections
– Clotting proteins
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Figure 7.5
Stem cells are
located in red
bone marrow
Stem cells multiply and
become specialized
Mature blood cells
Erythrocyte
(red blood cell)
Erythroblast
Nucleus
lost
Neutrophil
Eosinophil
Myeloblast
Granular
leukocytes
White
blood
cells
Basophil
Stem cell
Monoblast
Monocyte
Lymphocyte
Lymphoblast
Megakaryoblast
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Megakaryocyte
Platelets
Agranular
leukocytes
Red Blood Cells (Erythrocytes) Transport Oxygen
and Carbon Dioxide
 Make up almost half the blood volume
 5 million/mm3
 Functions: transport oxygen (O2) and some carbon
dioxide (CO2)
 Packed with hemoglobin, a protein which transports
O2
 Hemoglobin molecule includes heme groups which
each have iron atoms to which O2 binds
 Origin: stem cells in the bone marrow
 Life span: 120 days in humans
 Control of production: erythropoietin (hormone)
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Figure 7.4
Polypeptide chain
Heme group with
iron atom
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Red Blood Cells (RBC’s) Have a Short Life Span
 Stem cells in bone marrow will give rise to RBCs
 nucleus and organelles have been discarded in
mature red blood cells
 RBC’s live for about 120 days
 Aged RBC’s are removed by macrophages (large
phagocytic cells) in the spleen
 Iron and amino acids from hemoglobin are recycled
 Heme (minus the iron), is converted to bilirubin,
discarded through digestive tract
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RBC Production Is Regulated by a Hormone
 RBC number maintained by negative feedback
 Special cells in kidney monitor secrete hormone
erythropoietin (EPO) if O2 levels are low
 EPO stimulates stem cells in bone marrow—causes
increase in red blood cell production
 (Some athletes have abused EPO by injecting it to
increase their red blood cell production)
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Figure 7.6
O2 availability
Increase
Set point
Decrease
O2-sensitive cells in kidneys
respond to a decline in O2
availability by increasing
erythropoietin production
Increased number
of RBCs returns O2
availability to normal
Erythropoietin
stimulates increased
RBC production by
stem cells in
bone marrow
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White Blood Cells (Leukocytes) Defend the Body
 Arise from division of stem cells in bone marrow
 Make up 1% of whole blood
 Functions
– Protection from infection
– Regulation of the inflammatory reaction
 Two general types:
– Granular: neutrophils, eosinophils, and basophils
– Agranular: lymphocytes and monocytes
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Granular Leukocytes
 Neutrophils
– 60% of circulating WBCs
– First on the scene to fight infection by engulfing
microorganisms (especially bacteria)
 Eosinophils
– 2–4% of circulating WBCs
– Defend against large parasites (worms)
– Moderate the severity of allergic reactions
 Basophils
– 0.5% of circulating WBCs
– Histamine in granules—role in inflammation and
allergic reactions
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Agranular Leukocytes
 Monocytes
– 5% of circulating WBCs
– Leave the blood and transform into macrophages
 Lymphocytes
– 30% of circulating WBCs
– Play a large role in the immune response
– Two types
– B lymphocytes
– T lymphocytes
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Platelets Are Essential for Blood Clotting
 Bigger cells in the bone marrow break into
fragments called platelets
 Platelets play an important role in hemostasis
– If blood vessel is injured, platelets form a plug
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Hemostasis: Stopping Blood Loss
 Three stages
1. Vascular spasm: constriction of blood vessels to
reduce blood flow
2. Platelet plug formation: sealing of the ruptured
blood vessel
3. Coagulation: formation of a blood clot
– Blood changes from a liquid to a gel
– Complex series of reactions involving clotting proteins
in the plasma
– Last step is soluble fibrinogen forms an insoluble
mesh of fibrin
© 2014 Pearson Education, Inc.
Figure 7.8
Red blood cell
1 Vessel injury. Damage to a blood vessel
exposes the vessel layers and the
tissues to blood.
2 Vascular spasm. The blood vessel
contracts, reducing blood flow.
Platelets
3 Platelet plug formation. Platelets adhere
to each other and to the damaged vessel.
Fibrin strands
4
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Clot formation. Soluble fibrinogen forms
an insoluble mesh of fibrin, trapping around
the platelet plug
Human Blood Types
 Blood transfusion: administration of blood directly
into bloodstream
 Success depends on matching the blood type of the
donor with that of the recipient
– ABO blood types (A, B, AB, and O)
– Rh (Rh-positive and Rh-negative)
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ABO Blood Typing Is Based On A and B Antigens
 The A, B, antigens on the RBC surface determines
the blood type (A, B, AB, or O)
 Individuals have antibodies against the antigens
NOT on their own red blood cells
 If the recipient of a blood transfusion has antibodies
against the donated cells, a severe, possibly fatal
reaction may occur
© 2014 Pearson Education, Inc.
Figure 7.12
Type A
Type B
Type AB
Type O
Antigen A
Antigen B
Antigens
A and B
Neither A nor
B antigens
B
A
Neither A nor B
A and B
Red blood cells
Plasma antibodies
Incidences:
U.S. Caucasians
U.S. African Americans
Native Americans
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40%
27%
8%
10%
20%
1%
5%
4%
0%
45%
49%
91%
Rh Blood Typing Is Based On the Rh Factor
 Rh factor: another antigen found on red blood cell
surfaces
 85% of Americans are Rh-positive (have the
antigen)
 15% are Rh-negative
© 2014 Pearson Education, Inc.
Figure 7.13
Placenta separating
from uterus
Anti-Rh
antibodies
Anti-Rh
antibodies
Placenta
Umbilical cord
RH
Uterus
RH
Anti-Rh
antibodies
RH
RH
RH
RH
Fetal red
blood cells
(Rh)
Fetal
circulation
When an
Rh-positive
man fathers
a child by an
Rh-negative
woman, the
fetus may
inherit the Rh
positive antigen.
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Maternal
red blood
cells (Rh)
Maternal
circulation
During pregnancy or
more commonly at
childbirth, a small
amount of fetal
blood enters the
mother’s circulation.
Blood
flow after
pregnancy
Maternal
circulation
Over the next several
weeks the woman
develops antibodies
against the
Rh antigen.
Fetal
circulation
Maternal
circulation
When the woman becomes
pregnant with her second
Rh-positive child, antibodies
attack the fetus’s red
blood cells.
Blood
Disorders
Mononucleosis
Iron-deficiency
anemia
Hemorrhagic
anemia
Pernicious
anemia
Sickle-cell
anemia
Leukemia
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T/F? Blood is more viscous (thicker) than water.
T/F? Our blood is about 50% water.
T/F? One purpose of blood is to transport waste.
Where do new blood cells come from?
a. From stem cells in bones.
b. From cell division of mature red blood cells.
c. From blood-producing tissues in the liver.
Before receiving blood transfusion, your blood
type must be determined. What would happen if
you were given the wrong type of blood?
© 2014 Pearson Education, Inc.