1. Essentials of Human Anatomy
BLOOD
Chapter 9
Dr Fadel Naim
Ass. Prof. Faculty of Medicine
IUG 1

2. Blood Considered a connective tissue: contains
Cells
a liquid ground substance (called plasma)
dissolved protein fibers.
About four times more viscous (or thicker) than water.
Temperature of blood is about 1°C higher than measured body temperature.

3. Blood Volume varies with about 8% of body weight about 5 liters
body size
changes in fluid concentration
changes in electrolyte concentration
amount of adipose tissue
about 8% of body weight
about 5 liters

4. Blood Whole blood can be separated: Liquid component
cellular components

5. Components of Blood Erythrocytes (or red blood cells) Buffy coat
form the lower layer of the centrifuged blood
typically make up about 44% of a blood sample
Buffy coat
makes up the middle layer
thin, slightly gray-white layer composed of cells called leukocytes (or white blood cells) and cell fragments called platelets
forms less than 1% of a blood sample
Plasma
straw-colored liquid that rises to the top
generally makes up about 55% of blood

6. Components of Blood
Erythrocytes and the components of the buffy coat are called the formed elements.
Formed elements and the liquid plasma compose whole blood.

7. Functions of Blood – Transportation
Transports numerous elements and compounds throughout the body.
erythrocytes carry oxygen from the lungs to body cells and then transport carbon dioxide from the cells back to the lungs for expulsion from the body
blood plasma transports
nutrients that have been absorbed from the GI tract
hormones secreted by the endocrine organs to their target cells
plasma
carries waste products from the cells to organs such as the kidneys, where these waste products are removed

8. Functions of Blood – Regulation of Body Temperature
Regulates body temperature.
plasma absorbs and distributes heat throughout the body
for cooling the blood vessels in the dermis dilate and dissipate the excess heat through the integument
when the body needs to conserve heat, the dermal blood vessels constrict, and the warm blood is shunted to deeper blood vessels in the body

9. Functions of Blood – Regulation of pH Levels
pH is a measure of how alkaline or acidic a fluid is.
Neutral pH is measured at exactly 7.
Acidic fluids (e.g., orange juice) are between 0 and 7.
Alkaline fluids (e.g., milk) are between 7 and 14.
Blood plasma contains compounds and ions that may be distributed to the fluid among tissues (interstitial fluid) to help maintain normal tissue pH.
Blood plasma pH is continuously regulated at a value of 7.4 the pH level required for normal cellular functioning.

10. Functions of Blood – Maintenance of Fluid Levels
Maintains normal fluid levels in the cardiovascular system.
Prevents fluid loss.
Constant exchange of fluid between the blood plasma and the interstitial fluid.
If too much fluid is absorbed in the blood, high blood pressure results.
If too much fluid escapes the bloodstream and enters the tissues, blood pressure drops to unhealthy low levels, and the tissues swell with excess fluid.
To maintain balance of fluid exchange between the blood and the interstitial fluid, blood contains compounds (such as salts and some proteins) to prevent excess fluid loss in the plasma.

11. Functions of Blood – Protection
Leukocytes (white blood cells) help guard against infection by mounting an immune response if a pathogen or an antigen is found.
Plasma transports antibodies, which are molecules that can immobilize antigens until a leukocyte can completely kill or remove the antigen.
Platelets and blood proteins protect the body against blood loss by forming blood clots on damaged vessels.

12. Components of Plasma
Complex mixture of water, proteins, and other solutes.
When the proteins are moved from plasma, the remaining fluid is termed serum.
Water makes up about 92% of plasma’s total volume.
water facilitates the transport of materials in the plasma
Water %
Plasma proteins 7%
Other solutes %
Transports organic and inorganic molecules, formed elements, and heat

13. Plasma Proteins
The next most abundant materials in plasma are the plasma proteins.
Make up about 7% of the plasma.
6 and 8 grams of protein in a volume of 100 milliliters of blood (referred to as g/dl)
The plasma proteins include:
albumins
globulins
fibrinogen
regulatory proteins

14. Difference between Plasma and Interstitial Fluid
Plasma has more:
Dissolved O2 O2 diffuses out into tissue
Dissolved proteins (too big to cross caps.)
Albumins
Globulins
 globulins
 and  globulins
Fibrinogen
Similar concentration: Salts & small molecules

15. Plasma Electrolytes
absorbed from the intestine or released as by-products of cellular metabolism
sodium
potassium
calcium
magnesium
chloride
bicarbonate
phosphate
sulfate
sodium and chloride are most abundant

16. Formed Elements in the Blood
Erythrocytes
make up more than 99% of formed elements
primary function is to transport respiratory gases in the blood
Leukocytes
make up less than .01% of formed elements
contribute to defending the body against pathogens
Platelets
make up less than 1% of formed elements and
help with blood clotting

17. Hematocrit Percentage of erythrocytes in the blood.
Values vary slightly and are dependent on age and sex.
Adult males range between 42% and 56% .
Females range from 38% to 46%.
Childrens’ hematocrit ranges also vary and differ from adult values.
Altitude can affect the hematocrit.
body compensates by making more erythrocytes
more erythrocytes in the blood can carry more oxygen to the tissues

18. Erythrocytes Mature erythrocytes lack nuclei.
Transport oxygen and carbon dioxide to and from the tissues and the lungs.
Lack of nuclei enables them to carry respiratory gases more efficiently.

19. Hemoglobin in Erythrocytes
Every erythrocyte is filled with approximately 280 million molecules of a red-pigmented protein called hemoglobin.
Transports oxygen and carbon dioxide, and is responsible for the characteristic bright red color of arterial blood.
Hemoglobin that contains no oxygen has a deep red color that is perceived as blue because the blood within these veins is observed through the layers of the skin and the subcutaneous tissue.

20. Erythrocyte Life Cycle
No organelles, therefore can not sustain itself.
Finite life span of about 120 days.
Daily:
About 1% of oldest RBCs are removed
Are phagocytized by liver and spleen.
By macrophages
Some components saved, some discarded

21. Blood Types Determined by membrane proteins in the RBC cell membrane.
Called surface antigens (agglutinogens).
Most common group: ABO blood group
Two antigens: A and B
ABO blood types:
Type A: have the A surface antigen
Type B: have the B surface antigen
Type AB: have both the A and the B surface antigens
Type O: have neither the A or the B surface antigen.

22. Blood Types
Antibodies (agglutinins) to the surface antigens are in the plasma
ABO group has anti-A antibodies and anti-B antibodies
Type A: have anti-B
Type B: have anti-A
Type AB: has neither anti-A or anti-B
Type O: has both anti-A and anti- B

23. White Blood Cells leukocytes protect against disease
interleukins and colony-stimulating factors stimulate development
granulocytes
neutrophils
eosinophils
basophils
agranulocytes
lymphocytes
monocytes

24. Platelets Irregular, membrane-enclosed cellular fragments
about 2 micrometers in diameter (less than one-fourth the size of an erythrocyte).
Sometimes called thrombocytes.
Continually produced in the red bone marrow by cells called megakaryocytes.

25. THE END