OVERVIEW OF BLOOD

Blood• Functions– distribution

• oxygen and nutrients• removal of CO2 & wastes• hormones

– protection• prevent blood loss• prevent infection

– regulation• body temp. blood’s temp. 100.4 degrees F• normal Ph 7.35-7.45• volume

– males ~ 5-6 L– females ~ 4-5 L

Blood

• Fluid Tissue ~ connective– plasma– blood cells– hematocrit

• red blood cells 45%• Plasma 55%• Buffy coat less than 1 % contains white cells and platelets

Composition & Character• Plasma

– water• 90%

– protein• antibodies albumin fibrogen

– electrolytes• Na + K + Ca + Cl - Mg +

– other components• gases

– O2 and CO2

• glucose• fatty acids• vitamins

Red Blood Cells

• Erythrocytes– Transport oxygen to cells– Mature RBC lack a nucleus- eject it– Live 120 days – destroyed by the spleen– Made in red bone marrow– Small biconcave discs thinner in center– Females: 4.3-5.2 million cells/mm3– Males: 5.1-5.8 million cells/mm3

RBC

• Hemoglobin– Iron containing pigment– 12-18 g/100ml – Single cell has about 250 million hemoglobin molecules can bind with 4 oxygens Hematopoiesis- blood cell formation

red bone marrow stem cells

RBC

• Life span – 120 days• Anemia – decrease in O2 carrying capacity– Hemoglobin and or RBC deficiency– Symptoms: pale, cold, tired, short of breath– Causes • Sickle cells B12 deficiency• Hemorrhage Low iron• Bacterial infections

Platelets• Thrombocytes–Cell fragments–300,000/mm3–Hemostasis- stops blood flow “clots”–Platelets cling to damaged site, blood

clotting factors and fibrogen form fibrin and then clot–Hemostasis disorders thrombus embolus “clots” hemophilia - no clots

• White Blood Cells- Leukocytes– defense and immunity– contain nuclei and organelles– 5000 - 10,000 WBC’s– granular leukocytes• neutrophil’s ~ 3,000 - 7,000 54-62% of WBC

– phagocytes– multilobed nucleus stain pink grains deep purple

• eosinophils ~ 100-400 1-3% of WBC– chemicals to kill parasitic worms allergies– red granuals blue-red bilobed nucleus

• basophils ~ 20-30 less than 1% of WBC– secrete histamines - vasodilators – chemicals to kill foreign substances– few large blue-purple grains– u or s shaped nucleus

Agranulocytes

• Monocytes 100-700 3-9 % of WBC– Large cells two to three times larger than RBC– Phagocytes– Present in chronic infections

• Lymphocytes ~ 1500 – 3000 25-33%– small cells - r.b.c size– large dark purple nucleus– Provide immunity B cells and T cells– Secrete antibodies

–WBC count• leukocytosis

above 11,000 cells / mm 3– infection

• leukopenia– low count–drugs steroids flu mumps

measles AIDS • leukemia–too many immature WBC’s >

17,000• mononucleosis–too many abnormal monocytes

Blood Groups• Human Blood Groups– 30 common antigens on RBC’s– Antigens- agglutinogens• proteins on cell surfaces

– Antibodies- agglutinins• proteins made in response to foreign

antigens– agglutination• “clumping”• binding of antibodies to foreign

antigens

Blood Groups• ABO Systems

Blood Type Antigens Antibodies Can receive Can donate to

O None A & B O All

A A B A & O A & AB

B B A B & O B & AB

AB A & B None All AB

Blood Groups

• RH System– Rh – mother can make antibodies

against developing Rh+ fetus– eight different kinds of Rh antigens–most important is antigen D have Rh + – lack antigen D Rh - make Rh antibodies

• Blood Typing– cross matching