Download Chapter 11 - Blood Cardiovascular System

Chapter 11 - Blood!
Chapter 11 - Blood!
1!
Cardiovascular System!
Parts:!
Fluid!
" Blood, a fluid CT!
Pump!
" " Heart!
Conduits!
" " Blood vessels!
2!
1!
Chapter 11 - Blood!
Functions of Blood - 1!
1. Transportation of:!
•  Dissolved gases!
•  Nutrients!
•  Hormones!
•  Metabolic wastes!
•  Heat!
2. Regulation of pH and ion composition of ECF!
•  Contains buffers (Chapter 2)!
•  Diffusion eliminates differences between
blood and ECF!
3!
Functions of Blood - 2!
3. "Hemostasis – blood clotting minimizes fluid loss
at injuries!
4. Defense against pathogens, toxins!
•  White blood cells!
5. Body temperature regulation!
•  Redistributes heat!
•  Facilitates heat loss or heat gain!
4!
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Chapter 11 - Blood!
Composition of Whole Blood "
"
Figure 11.1!
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Composition of Whole Blood!
1. Plasma is the fluid portion of blood!
2. Formed elements in blood!
•  Red blood cells (erythrocytes)!
•  White blood cells (leukocytes)!
•  Platelets (thrombocytes)!
Hemo- or hematopoiesis = blood cell formation!
6!
3!
Chapter 11 - Blood!
Characteristics of Normal Whole Blood!
1. Temperature about 38° C!
2. Viscosity = stickiness, cohesiveness!
•  5 times more viscous than water"!
3. pH: 7.35 - 7.45 (normal)!
4. Blood volume!
•  Adult male: 5 - 6 liters!
•  Adult female: 4 - 5 liters!
7!
Composition of Plasma!
Composition:!
A. 92% water!
B. 7% plasma proteins!
"Albumins, globulins, fibrinogen!
•  Much higher [protein] (5X) than ECF!
Proteins too large to leave vessels!
•  Osmotic pressure, clotting, immune
responses, etc.!
C. 1% other solutes!
•  Electrolytes, organic nutrients/wastes,
etc.!
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4!
Chapter 11 - Blood!
Red Blood Cells - Erythrocytes!
Contain hemoglobin carry O2 and
CO2!
99% of formed elements are
RBCs!
Hematocrit = % of whole blood
that is cells"
•  Average male: 46%!
•  Average female: 42%!
Plasma!
WBCs in
“buffy
layer”!
RBCs!
9!
RBC Structure!
Biconcave discs - about 8 µm in
diameter!
No nucleus or most other
organelles!
•  No nucleus → limited lifespan!
•  No mitochondria (why?)!
About 3 million new RBCs produced per second
in red bone marrow!!!!
Table 11.1!
10!
5!
Chapter 11 - Blood!
Hemoglobin (Hb) Structure!
Hb Structure:!
4 polypeptides and 4 heme groups!
•  Heme = iron-containing pigment!
•  O2 reversibly binds to iron in heme!
In adults: !
•  2 α and 2 β chains (4 polypeptides, 4 hemes)!
•  Each Hb molecule can therefore carry 4 O2!
Oxyhemoglobin abbreviation: HbO2!
11!
Hemoglobin Structure
"
"
"
Figure 11.5!
“-globin”
means
globular
protein!
12!
6!
Chapter 11 - Blood!
Stimulus for RBC Production!
Stimulus = hypoxia = low tissue O2!
•  Causes erythropoietin (EPO) release from
kidneys!
Causes of tissue hypoxia!
•  Anemia:!
Decreased hematocrit or [Hb]!
•  Low blood flow to kidneys!
•  Decreased O2 content of air (e.g. high
altitude)!
•  Lung damage!
13!
RBC Production
"
"Figure 11.6!
Hypoxia!
14!
7!
Chapter 11 - Blood!
Blood Typing!
Antigen = a substance that triggers an immune
response!
Antibody = globular protein that binds antigen!
•  RBC membranes may or may not have
glycolipid or glycoprotein surface antigens
(agglutinogens)!
•  Plasma may or may not contain antibodies
(agglutinins)!
•  Binding of antibodies to antigens causes:!
ü Agglutination (clumping)!
ü Hemolysis (rupture of RBCs)!
"
You should be able to figure this out."
ABO Blood Groups "
"
"
15!
Table 11.2!
….FYI only.......16!
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Chapter 11 - Blood!
The Bottom Line on Transfusion Reactions!
!
The bottom line question to ask is:"
Does the recipient’s blood have
antibodies that can attack antigens on
the donated blood cells?
!
!
!
L!
If No - Theoretically O.K. J!
If Yes - “Major Bummer”
17!
Transfusion Example #1!
(Assume Rh factor (later) is compatible.)!
Recipient
(large volume)
Donor
(small volume)
Type
RBC antigens
Plasma
antibodies
A
A
Anti-b
B
B
Anti-a
Will this transfusion be successful? !
•  I.e. will a transfusion reaction occur? !
•  Why or why not?!
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Chapter 11 - Blood!
Transfusion Example 2 (Assume Rh factor (later) is compatible)!
Recipient
(large volume)
Donor
(small volume)
Type
RBC
antigens
Plasma
antibodies
AB
AB
None
A
A
Anti-b
Will this transfusion be successful?!
Why or why not?!
19!
Rh Factor!
“Rh” comes from Rhesus monkey in which this
was first studied!
•  Also called D antigens!
•  Person with Rh antigens on RBCs is Rh+"
•  Person without Rh antigens on RBCs is Rh-"
•  E.g. AB+ has A, B and Rh antigens on RBCs"
Major difference from ABO grouping:!
A Rh- person who has never been
exposed to Rh+ blood DOES NOT have
anti-Rh antibodies.!
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Chapter 11 - Blood!
Importance of Rh Factor - 1!
1. Rh- person (male or female) receives Rh+
blood (proper ABO match) transfusion!
•  First transfusion O.K. (mild or no reaction)!
•  But recipient now begins making antibodies
against Rh factor!
•  Second transfusion now a potential problem!
21!
Importance of Rh Factor - 2!
2. Pregnant female:!
"Rh- mother and Rh+ father → Rh+ fetus (by chance )!
A. First pregnancy probably O.K., but!
•  During delivery, maternal and fetal blood
may mix!
•  Mother makes anti-Rh antibodies!
B. Next pregnancy with Rh+ fetus:!
•  Maternal antibodies may cross placenta!
•  Produce hemolytic disease of the newborn!
"
"(a.k.a. erythroblastosis fetalis)!
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Chapter 11 - Blood!
Rh Factors and Pregnancy!
First pregnancy
with Rh+ fetus!
Second
pregnancy with
Rh+ fetus!
RhoGam:"
•  Anti-Rh antibodies"
•  Destroy fetal Rh+ "
RBCs before "
mother’s "
Rh+ fetus!
body makes "
antibodies against "
them"
•  Generally given "
last trimester and"
delivery"
23!
White Blood Cells (WBCs or Leukocytes)!
Have a nucleus, unlike RBCs!
About 1% of all formed elements!
•  Circulate in blood for limited times!
•  Migrate to connective tissues of body!
Granulocytes:!
•  Neutrophils, basophils, eosinophils!
Agranulocytes:!
•  Monocytes, lymphocytes!
24!
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Chapter 11 - Blood!
White Blood Cells (WBCs) = Leukocytes!
Table 11.1!
……….FYI only..........
25!
1. Neutrophils!
Normally the most numerous
WBC!
Functions:!
•  “First line of defense”!
•  Phagocytize
pathogens!
•  Release chemicals that!
"attract other WBCs!
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13!
Chapter 11 - Blood!
2. Eosinophils!
Normally rare"
Functions:!
•  Phagocytize antigenantibody complexes!
•  Attack some parasitic
worms!
•  Release antihistamine!
Turns off inflammation
response!
(No, they don’t always look like E.T.)!
27!
3. Basophils!
Normally extremely rare"
Intensify inflammation:!
Release histamine"
•  Dilates small vessels!
•  Increases capillary
permeability!
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Chapter 11 - Blood!
4. Monocytes Become Macrophages!
Normally <10% of WBCs!
Functions:!
•  Phagocytic!
•  Act as antigenpresenting cells!
•  Call other WBCs to
infection site!
29!
5. Lymphocytes!
20 - 30% of WBCs in
blood!
But most lymphocytes
are in the tissues and
lymphatic organs at
any one time (i.e. not
in the blood).!
30!
15!
Chapter 11 - Blood!
Lymphocyte Types and General Functions - 1!
A. B cells attack a specific antigen!
Differentiate into plasma cells which:!
• 
• 
Secrete antibodies!
(Label invader for destruction)!
Act as antigen-presenting cells!
B. T cells attack a specific antigen!
•  Attack virus-infected and cancerous cells,
transplanted tissues!
• 
• 
• 
Cytotoxic (Killer) T cells!
Helper T cells!
Suppressor T cells!
31!
Lymphocyte General Functions - 2!
C. Natural Killer (NK) cells perform “immune
surveillance”!
Function:!
•  Each can attack a variety of antigens"
"(B and T cells are much more specific)!
•  Kill microbes, cancerous cells!
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Chapter 11 - Blood!
Platelets (Thrombocytes)!
Fragments of megakaryocytes!
(i.e. are not really cells)!
Very small compared to RBC!
!
Function in blood clotting!
33!
Hemostasis!
Hemostasis = stoppage of bleeding!
Three phases:!
1.  Vascular phase (vascular spasm)!
2.  Platelet phase (platelet plug formation)!
3.  Coagulation phase (blood clotting)!
...FYI only...
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17!
Chapter 11 - Blood!
Platelet and Clotting Phases "
Figure 11.9!
(Factor X)"
(Prothrombinase)"
“Inactive blood protein” = Factor X"
“Prothrombin activator” = Prothrombinase"
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18!