Blood Chapter 10

Features of Blood pH between 7.35 – 7.45 (slightly alkaline) Sticky Opaque – not translucent Has metallic taste

Plasma Makes up 55% of the blood Approximately 90% water Dissolved substances  Nutrients  Salts  Respiratory gases (O 2 and CO 2 )  Hormones  Plasma proteins  Waste

Plasma (cont.)

Formed Elements Makes up 45% of the blood Three types of formed elements (cells)  Erythrocytes (RBCs)  Leukocytes (WBCs)  Platelets

Formed Elements (cont.) Erythrocytes  Transport oxygen in blood  Anucleated (without nucleus)  Doughnut shaped  Life span: 100 to 120 days  4-6 million RBCs in the body RBC outnumber WBC 1,000 to 1  Hemoglobin – an iron-containing protein that oxygen attach to for transportation Iron – The element that gives erythrocytes their red color

Formed Elements (cont.) Erythrocyte disorders  Anemia – a decrease in the oxygen-carrying ability of the blood May result from:  A lower than normal number of RBCs  Deficient hemoglobin content in the RBCs  Sickle-cell anemia – deformed (crescent shaped) RBCs rupture easily and can cause blood clots

Formed Elements (cont.) Leukocytes  4,000-11,000 WBCs in the body Less than 1% of total blood volume  Nucleated  Can move by amoeboid motion  WBCs defend the body against damage by bacteria, viruses, parasites, and tumor cells  When infection occurs, WBCs double in number within hours

Formed Elements (cont.) Types of Leukocytes  Granulocytes – WBCs that have grains (or dots) Neutrophils – Fight acute bacterial infections  Most common WBC - 40% to 60% Eosinophils – Kill parasitic worms; increase during allergy attacks  1% to 4% Basophils – Produces histamine  Least common WBC - 0.5% to 1%

Formed Elements (cont.) Types of Leukocytes (cont.)  Agranulocytes – WBCs that do not have grains Lympocytes – Fight viral infections, fungal infections, and cancer cells 20% to 40% Monocytes – Fight chronic bacterial infections; makes up long-term “clean-up team” 2% to 8%  Note: Granulocytes end in –phils and agranulocytes end in –cytes

Formed Elements (cont.) List of the WBCs from most to least abundant  Neutrophils  Lymphocytes  Monocytes  Eosinophils  Basophils Easy way to remember this list  Never  Let  Monkeys  Eat  Bananas

Formed Elements (cont.) Abnormal leukocyte activity  Leukocytosis – a total WBC count above 11,000 cells/mm 3 Leukocytosis indicates a bacterial or viral infection is present in the body  Leukopenia – an abnormally low WBC count Caused by certain drugs such as corticosteroids and anticancer agents  Leukemia – cancer of the blood cells that starts in the bone marrow

Formed Elements (cont.) Platelets – Fragments of cells that are used in the clotting process

Hemostasis Hemostasis – stoppage of blood flow Blood usually clots within 3 to 6 minutes Hemostasis has four phases:  Platelets fill the cut  Clotting proteins activate  Fibrin forms  RBCs and WBCs coagulate with other coagulated components bZUeb83uU bZUeb83uU

Hemostasis (cont.) Disorders of Hemostasis  Undesirable Clotting Thrombus – A clot that develops and persists in an unbroken blood vessel Embolus – A thrombus breaks away from the vessel wall and floats freely in the bloodstream  For example, a cerebral embolus may cause a stroke  Bleeding Disorder Hemophilia – a lack of any of the factors needed for clotting

Blood Groups Antigen (or agglutinogen) – a sugar or protein that is attached to the surface of erythrocytes  Antigens are sugars in ABO blood groups  Antigens are proteins in the Rh blood group Antibody (or agglutinin) – a protein produced by the body's immune system

Blood Groups

Blood Groups (cont.) Blood GroupFrequency for White Americans Frequency for Black Americans Frequency for Asian Americans Blood that can be received AB445A, B, AB, O (universal recipient) B112027B, O A402728A, O O454940O (universal DOnOr)

Blood Groups (cont.) Rh Blood Groups  Originated from rhesus monkeys  Rh + - RBCs carry the Rh antigen  Rh - - RBCs that do not carry the Rh antigen Anti- Rh + antibodies are not automatically present in the blood of Rh - individuals. If an Rh - person receives mismatch blood (Rh + ), their immune system becomes sensitized and begins producing anti- Rh + antibodies against the foreign blood.

Blood Groups (cont.) Rh Blood Groups  Pregnant women The same concept occurs in pregnant Rh - women that carry Rh + babies. The first pregnancy will result in a healthy baby. The mother is now sensitized by Rh + antigen. The doctor will treat her with RhoGAM (an immune serum that prevents this sensitization) during the second pregnancy.  Serum – plasma without clotting proteins  If mother is not treated, the baby can become anemic, have brain damage, or die.