The Cardiovascular System:
The Blood
A. Components of blood
1. Blood plasma
2. Formed elements
B. Formation of blood cells
C. Erythrocytes (red blood cells)
1. RBC anatomy
2. RBC physiology
3. RBC lifespan and number
D. Leukocytes (white blood cells)
1. WBC anatomy and types
2. WBC physiology
3. WBC lifespan and number
E. Thrombocytes (platelets)
F. Hemostasis
1. Vascular spasm
2. Platelet plug formation
3. Coagulation (clotting)
4. Fibrinolysis
G. Grouping (typing) of blood
1. ABO
2. Rh
The more specialized a cell becomes to
perform a specific function, the less
capable it is of an independent
existence.
As a result, it cannot:
1. protect itself
2. seek and procure food
3. move away from its own wastes
Internal Environment
1. Extracellular fluid
(ECF)
a. interstitial fluid
b. plasma
c. lymph
2. Intracellular fluid
General Properties of Blood
Components of Blood
Formed Elements (45%)
1. erythrocytes (RBCs)
2. leukocytes (WBCs)
3. thrombocytes (platelets)
Components of Blood
(Plasma ( 55%)
Plasma Components
A. water (91.5%)
B. solutes (8.5%)
(1) albumins (54-60%)
(2) globulins (36-38%)
(3) fibrinogen (4-7%)
What is a hematocrit?
Hematopoiesis
Yolk sac stage (3rd week – end of 2nd month)
Hepatic stage (beginning of 2nd month – just after birth)
Myeloid stage (beginning of 5th month – death)
Hematopoiesis (Hemopoiesis)
1.
2.
3.
a.
b.
c.
hemocytoblast
stem cells
growth factors
erythropoietin
thrombopoietin
leukopoietins (?)
hemocytoblast
myeloid
stem cell
lymphoid
stem cell
lymphocytes
erythrocytes
megakaryocytes
neutrophils
eosinophils
basophils
monocytes
B cells
T cells
Erythrocytes
1.
2.
3.
4.
5.
6.
7-10 um diameter
biconcave disc
large surface area
very flexible
not "true" cells
sacs of hemoglobin
males = 4.6 – 6.2 million/mm3 hematocrit = 45-52%
females = 4.2 – 5.4 million/mm3 hematocrit = 37-48%
Hemoglobin
1.
2.
3.
4.
5.
1 globin (protein)
4 Fe-containing heme groups
1 O2/heme
1 Hb = 4 O2
1 globin = 1 CO2
Hemoglobin value:
Normal: Female 12-16 g/dL
Male
13-18 g/dL
Sickle Cell Anemia
RBC Lifespan
1. 120 days
2. synthesis (2 million/sec)
a. required substances
b. erythropoietin regulation
3. destroyed by liver and spleen
(2 million/sec)
4. recycled hemoglobin
a. hemosiderin
b. bilirubin
c. amino acids
Erythrocyte Lifespan
120 days in circulation
Synthesis (2 million/sec)
decreased blood O2
negative
feedback
required substances
iron (Fe3+ )
globulin
vitamin B12
erythropoietin
kidneys release
erythropoietin
stimulates
myeloid stem cells
produce RBCs
increased blood O2
new RBCs liberated
into bloodstream
erythropoietin regulation
Destroyed by liver and
spleen (2 million/sec)
Recycling of hemoglobin
RBCs destroyed
Hb released
broken down to
biliverdin
hemosiderin
+
globin
broken down to
bilirubin
excreted
Fe 3+
amino acids
recycled
The Life And Death of
Erythrocytes
Leukocytes (WBCs)
= 5,000 – 10,000/mm3
1. granulocytes
a. neutrophils (60 - 70%) phagocytize bacteria; 1st line of defense
b. eosinophils (2 - 4%) phagocytize Ab-Ag complexes and allergens;
anti-parasitic
c. basophils (0.5 - 1%) secrete histamine and heparin
2. agranulocytes
d. lymphocytes (20 - 25%)- immunity
e. monocytes (3 - 8%) become macrophages; phagocytosis;
Ag-presentation
WBC Physiology
1.
2.
3.
4.
5.
6.
7.
8.
chemotaxis
chemotactic factors
margination
pavementing
diapedesis
emigration
ameboid motion
short lifespan
1. and 2.
7.
7.
5. and 6.
3. and 4.
Thrombocytes (Platelets)
= 130,000 – 360,000/mm3
1.
2.
3.
4.
5.
6.
7.
megakaryocyte
cytoplasmic fragment
not "true" cell
biconvex disc
2 um diameter
clotting factors
lifespan 5 - 9 days
Hemostasis= Stoppage of
Bleeding
Three basic mechanisms go into
operation at the same time:
1. vascular spasm
2. platelet plug formation
3. coagulation
Three Basic Mechanisms of
Hemostasis
1. adhesion
2. release reaction
3. aggregation
Coagulation (Clotting)
1. clot
2. serum
3. three basic processes
a. prothrombinase
b. prothrombin --> thrombin
c. fibrinogen --> fibrin
4. clot retraction (syneresis)
Prothrombinase
Fibrinogen
Fibrinolysis = dissolution of a
clot
Plasminogen activating factor (kallikrein)
(converts)
plasminogen
plasmin
clot
dissolved clot
Grouping (Typing of Blood)
1. glycolipid agglutinogens
2. two major blood group systems
a. ABO
b. Rh
Blood Types
Membrane Bound Agglutinogens (Antigens)
ABO Blood System and Rh System
Plasma antibodies (agglutinins)
(Anti A and Anti B- no anti Rh)
Cause agglutination and hemolysis
Type A
Type B
Type AB
Type O
Agglutinogen B
Agglutinogens A and B
No Agglutinogens
Agglutinin A
Neither
Agglutinin A or B
RBCs
Agglutinogen A
Plasma
Agglutinin B
Both Agglutinin
A and B
Who can give what to whom?
Recipient is type A. Can she receive:
type A plasma
type A RBCs
type B plasma
type B RBCs
type AB plasma
type AB RBCs
type O plasma
type O RBCs
Who can give what to whom?
Recipient is type B. Can she receive:
type A plasma
type A RBCs
type B plasma
type B RBCs
type AB plasma
type AB RBCs
type O plasma
type O RBCs
Who can give what to whom?
Recipient is type AB. Can she receive:
type A plasma
type A RBCs
type B plasma
type B RBCs
type AB plasma
type AB RBCs
type O plasma
type O RBCs
Who can give what to whom?
Recipient is type O. Can she receive:
type A plasma
type A RBCs
type B plasma
type B RBCs
type AB plasma
type AB RBCs
type O plasma
type O RBCs
Rh System of Grouping
1. agglutinogen Rh
2. no agglutinin
_________________
hemolytic disease of the newborn
(erythroblastosis fetalis)