1. Biology 212 Anatomy & Physiology I
Blood

2. Blood: Volume: 4 - 6 liters, ~ 8% to 9% of body weight Components:
Formed Elements:
Erythrocytes (Red blood cells)
Leukocytes (White blood cells)
Platelets
Plasma:
Water
Many proteins
Ions, nutrients, wastes, hormones, etc
pH: , Buffered to remain stable

4. Erythrocytes Primary Function - Transport of oxygen and carbon dioxide
Cytoplasm full of hemoglobin
Biconcave disks
~7.5 um diameter
~2 um thick
No nucleus
million per microliter
(cubic millimeter)
billion per milliliter
(cubic centimeter)
Slightly higher in men

5. Hemoglobin Each molecule: 4 large Globin proteins
Each surrounding an iron-
containing Heme Group
Oxygen reacts reversibly with iron:
Binds in lungs
Unbinds in consumer tissues

6. Erythrocyte formation = erythropoiesis
Occurs in bone marrow
Developing erythrocytes = erythroblasts

7. Erythropoiesis regulated by hormone erythropoietin produced by kidneys

8. Erythrocytes also carry specific glycoproteins, or antigens, on their surfaces which are responsible for blood types
If transfused into person with incompatible blood type, antibodies in recipient's serum will react with these antigens & cause erythrocytes to stick together or agglutinate

9. Erythrocytes normally survive ~120 days in circulation
Trapped and destroyed (mostly in spleen)
Iron salvaged from hemoglobin, returned to bone marrow

10. Leukocytes (White blood cells) Five different types of cells
All formed in
bone marrow
4,000 to 10,000 per cubic millimeter or
4,000,000 to 10,000,000 per milliliter (cubic centimeter)

11. Each type has
specific functions,
but in general:
Leukocytes function in body defenses by:
Engulfing & digesting invading organisms & debris
Directly killing invading cells
Producing antibodies
Secreting chemicals which activate other immune cells
Secreting chemicals which promote inflammation

12. Leukocytes Grouped into two categories based upon appearance
of granules in
cytoplasm:
Abundant, distinct granules = Granular Leukocytes
or Granulocytes
Few, small granules = Agranular Leukocytes
or Agranulocytes

13. Granular
Leukocytes
Named according
to how these
granules react to
routine lab stains
("Wright's Stain"
is most common)
The nucleus of each type also has a characteristic shape and/or density
Three types: Neutrophils, Eosinophils, Basophils

14. Neutrophils
40% - 60% of
leukocytes
in blood.
Granules present
in cytoplasm but
stain weakly with
both acidic and
basic stains
Nucleus has 3 to 7 lobes
Also called Polymorphonuclear Leukocytes

15. Eosinophils
1% - 4% of
leukocytes
in blood.
Granules attract
acidic stain eosin,
therefore stain
red or orange
Nucleus is indented or bilobed

16. Basophils
0.5% - 1% of
leukocytes
in blood.
Granules attract
the basic stain
hematoxylin,
therefore stain
blue or purple
Nucleus is indented or bilobed, but is often obscured by the granules
Outside of circulation: Mast cells

17. Agranular
Leukocytes
Two unrelated
types of
leukocytes,
neither of which
has abundant
granules:
Lymphocytes, Monocytes
The nucleus of each type also has a characteristic shape and density

18. Monocytes
4% to 8% of
leukocytes in
blood
Nucleus indented,
may be kidney
shaped or
horseshoe shaped.
Stains only moderately blue.
Cytoplasm is abundant, typically stains an even
light blue or bluish-gray
Outside of circulation: Macrophages

19. Lymphocytes
20% to 40% of
leukocytes in
blood
Nucleus usually
spherical, may be
slightly indented.
Stains darker blue.
Varying amounts of cytoplasm which stains a pale to medium blue

20. Lymphocytes
Two types of
lymphocytes with
different functions
in immune system,
but they appear
identical in blood:
T-lymphocytes and B-lymphocytes

21. All leukocytes formed in bone marrow, then enter blood
But: Not particularly active when in the blood.
Most leukocytes are using the blood to get to other
tissues and organs, where they differentiate and
become active

22. Since they generally function outside of the circulatory system, primarily in the connective tissues of other organs,
All leukocytes can leave (and most can also reenter) the blood vessels by a process called Diapedesis.
Therefore: All of the leukocytes, and the cells which they mature into, are normally found in connective tissues throughout the body

23. Platelets
Function in
clotting of blood
when vessels
are injured
250,000 to 500,000 per cubic millimeter or
250,000,000 to 500,000,000 per milliliter (cubic centimeter)

24. Platelets
Fragments of much
larger cells, called
megakaryocytes,
which remain in the
bone marrow

25. When blood vessels are damaged, the flow of blood through them must be stopped until the body can repair the injury.
This is called Hemostasis
It involves three processes in rapid sequence:
Narrowing of the vessel reduces the flow of blood near the injury
Vasospasm

26. When blood vessels are damaged, the flow of blood through them must be stopped until the body can repair the injury.
This is called Hemostasis
It involves three processes in rapid sequence:
Vasospasm
Platelet Plug

27. - Under normal conditions, platelets do not stick to each
Formation of a Platelet Plug
- Under normal conditions, platelets do not stick to each
other or to the walls of blood vessels
- When a blood vessel is injured, it releases chemicals
which cause platelets to attach to each other and to the
injured part of the vessel. This is platelet activation.
- As new platelets attach, they also become activated
and release more chemicals which attract and activate
more platelets

28. When blood vessels are damaged, the flow of blood through them must be stopped until the body can repair the injury.
This is called Hemostasis
It involves three processes in rapid sequence:
Vasospasm
Platelet Plug
Fibrin Clot

29. - This involves a series of sequential chemical reactions
Formation of a Fibrin Blood Clot
- This involves a series of sequential chemical reactions
in which the products of the first reaction serve as the
catalysts of the second reaction, whose products are the
catalysts of the third reaction, whose products are the
catalysts of the fourth reaction, etc.
- This allows for a very rapid increase in the rate at which
the clot forms.
- It also allows many chances to stop the process if it
began by mistake or gets too far away from where the
vessel was injured.

30. Formation of a fibrin blood clot involves 13 "clotting factors".
Each of these is the reactant for the next of these sequential reactions
Factor
Synonyms
Factor I
Fibrinogen
Factor II
Prothrombin
Factor III
Tissue Thromboplastin
Factor IV
Calcium
Factor V
Proaccelerin
Factor VI
Labile Factor
Factor VII
Prothrombin accelerator
Factor VIII
Antihemophilic Factor A
Factor IX
Antihemophilic Factor B
Factor X
Stuart Factor
Factor XI
Thromboplastin Antecedent
Factor XII
Hageman Factor
Factor XIII
Fibrin Stabilizing Factor

31. Formation of a fibrin blood clot involves 13 "clotting factors".
Each of these is the reactant for the next of these sequential reactions
Last reaction: Plasma
protein fibrinogen is
converted to large fibers
of fibrin, which forms a
dense mesh and traps erythrocytes, platelets, and leukocytes

32. Once the fibrin clot has formed, it is stabilized by enzymatic formation of covalent crosslinks among the strands of fibrin.
Over the next 30 to 60 minutes, the clot retracts, becoming denser and more solid.
End result: Dense network of interconnected strands of fibrin with platelets, erythrocytes, and leukocytes trapped within it.

33. Over next few days, after vessel has time to repair itself:
Clot is dissolved and
removed by process
called fibrinolysis.
Plasma protein
plasminogen
converted to active
enzyme plasmin
which dissolves
fibrin.