Composition of Blood Blood is the body’s only fluid tissue –It is composed of liquid plasma and formed elements Formed elements include: –Erythrocytes, or red blood cells (RBCs) –Leukocytes, or white blood cells (WBCs) –Platelets are just cell fragments Platelets Hematocrit – the percentage of RBCs out of the total blood volume

Blood Plasma Blood plasma contains over 100 solutes, including: –Proteins – albumin, globulins, clotting proteins, and others –Nonprotein nitrogenous substances – lactic acid, urea, creatinine –Organic nutrients – glucose, carbohydrates, amino acids, fatty acids –Electrolytes – sodium, potassium, calcium, chloride, bicarbonate –Respiratory gases – oxygen and carbon dioxide

Components of Whole Blood Withdraw blood and place in tube 1 2 Centrifuge Plasma (55% of whole blood) Formed elements Buffy coat: leukocyctes and platelets (<1% of whole blood) Erythrocytes (45% of whole blood)

Immunocompetent –All of ours cells have markers (antigens) on it’s cell membrane that identify it to your immune system as self. –(There are many known antigens on the surface of RBCs Classification on blood type is done with ABO blood groups: –Two antigens aka. (Agglutinogens) (A and B) on the surface of the RBCs that allow immune system to recognize cell as self. –Two antibodies( agglutinins) in the plasma (anti-A and anti-B) –Blood type is determined by the antigen Blood type A= has A antigen and B antibody Blood type B= has B antigen and A antibody Blood type O= has no antigens but both antibodies A and B Antigens and their corresponding antibodies cannot be mixed without serious hemolytic reactions –For example Blood type A mixed with anti A ABO Blood Groups

Transfusion Reaction Agglutinated RBCs block blood vessels and hemolyze –free Hb blocks kidney tubules, causes death

Rh Group Rh (D) agglutinogens discovered in rhesus monkey in 1940 –Rh + blood type has D agglutinogens on RBCs –Rh + would be negative for Anti-D agglutinins (antibodies) These antibodies are not normally present unless a Rh - individuals exposed to Rh + blood Rh - woman with an Rh + fetus or transfusion of Rh + blood

Hemolytic Disease of Newborn No problems with first pregnancy because fetal/material blood don’t mix until delivery –Rh - women bodies need time to develop the antibodies If Rh - women has formed antibodies and is pregnant with 2 nd Rh + child –Anti-D antibodies can cross placenta and cause severe hemolytic anemia Prevention –RhoGAM given to pregnant Rh - women binds fetal agglutinogens so she will not form Anti-D antibodies

Hemolytic Disease of Newborn Rh antibodies attack fetal blood –causing severe anemia Fig

Complete Blood Count Looking at the blood can give us a lot of clinical information: –Total count for RBCs (Reticulocytes), Hematocrit and hemoglobin concentration –O 2 carrying capacity ( anemia's) –Platelets count Increase risk of bleeding vs. clotting. –Differential WBC count Give us insight to the condition. –Cancer, infections, immune system function?

Figure 18.1

Formed Elements of Blood

Leukocyte Descriptions Granulocytes –neutrophils (60-70%) fine granules in cytoplasm; 3 to 5 lobed nucleus –eosinophils (2-4%) large rosy-orange granules; bilobed nucleus –basophils (<1%) large, abundant, violet granules (obscure a large S-shaped nucleus) Agranulocytes –lymphocytes (25-33%) variable amounts of bluish cytoplasm (scanty to abundant); ovoid/round, uniform dark violet nucleus –monocytes (3-8%) largest WBC; ovoid, kidney-, or horseshoe- shaped nucleus

Granulocyte Functions Neutrophils (  in bacterial infections) –phagocytosis of bacteria –release antimicrobial chemicals such as lysosomes and peroxidase –They are considered first responders in acute bacterial infections Eosinophils (  in parasitic infections or allergies) –phagocytosis of antigen-antibody complexes, allergens and inflammatory chemicals –release enzymes such as acid phosphotase to destroy parasites Basophils (  in chicken pox, sinusitis, diabetes) –secrete histamine (vasodilator): this increases vessel permeability to allow other WBC’s to an inflamed site. –secrete heparin (anticoagulant) prevent clotting allowing mobility of other WBC’s

Agranulocyte Functions Lymphocytes (  in diverse infections and immune responses) –Are divided into T and B Lymphocytes –destroy cells (cancer, foreign, and virally infected cells) –“present” antigens to activate other immune cells –coordinate actions of other immune cells –secrete antibodies and provide immune memory Monocytes (  in viral infections and inflammation) –differentiate into macrophages –“present” antigens to activate other immune cells –They are the clean up crew. They come in after the Neutrophils and phagocytize everything. –They will be elevated in chronic conditions

Leukocytes (WBCs) Agranulocytes: no visible cytoplasmic granules Granulocytes: contain visible cytoplasmic granules Neutrophils 60% Never Lymphocytes 30% Let Monocytes 8% Monkeys Eosinophils 2% eat Basophils.5% Bananas

Receiving Blood From a Donor Type A can receive blood from types A and O –A has anti-B, O has no surface antigens Type B can receive blood from types B and O –B has anti-A, O has no surface antigens Type AB can receive blood from types A, B,AB and O –Has no antibodies –(universal recipient) Type O can receive blood from type O –Has both anti-A and B antibodies in the plasma –will react to all other types except itself Rh + blood can receive blood from Rh + and Rh - blood –Doesn’t have anti-Rh antibodies in their plasma Rh - blood can receive blood from Rh - blood –No anti-Rh antibodies or no surface antigens

Giving Blood to a Recipient Type A can give blood to types A and AB –A has anti-B, AB has no antibodies in the plasma Type B can give blood to types B and AB –B has anti-A, AB has no antibodies in the plasma Type AB can give blood to type AB –All other have antibodies in plasma Type O (universal donor) can give blood to types A, B, AB and O –has no surface antigens to react with. Rh + blood can give blood to Rh + blood –Doesn’t have anti-Rh antibodies in their plasma Rh - blood can give blood to Rh + and Rh - blood –Has no anti-Rh antibodies but no surface antigens