Blood System

Blood  What is Blood? (Hem/o or hemat/o) Blood is a fluid tissue containing many suspended cells and can be found flowing through the circulatory system transporting substances. Can you name some of the substances transported by the blood?

Substances Transported by Blood  CO 2 from the body cells to the lungs  Nutrients from the digestive tract to body cells  Metabolic and Waste Products from body cells to the organs of excretion  O 2 from the lungs to the body cells  Heat produced by various body parts  Hormones from endocrine glands to the body organs Apart from the transportation of substances, blood also serves to protect the body against pathogens.

Blood Composition  The average human being has 5 liters (4-6 quarts) of blood in the body.  55% of the blood is made up of plasma - the liquid part of the blood.  45% of the blood is made up formed elements or blood cells - red blood cells, white blood cells and platelets.

Plasma  Plasma is a pale yellow fluid  Contains nutrients, wastes, hormones and dissolved gases  91% water, 9 % proteins  Fibrinogen & prothrombin are clotting proteins that help blood clot and control bleeding 

Erythrocytes Erythrocytes (erythr/o = red + cyte = cell)  Also called red blood cells (RBC’s)  Contains hemoglobin (hem/o = blood + -globin = protein) which is the iron containing portion of erythrocyte  Hemoglobin transports oxygen from the lungs to the tissues of the body  Live about 120 days (3-4 months)  Produced in the red bone marrow

Leukocytes Leukocytes (leuk/o= white + cyte=cell)  Also called white blood cells (WBC’s)  Protect the body against infection  Live about 3-9 days  There are five types of leukocytes: Neutrophils Think:Never LymphocytesLet MonocytesMonkeys EosinophilsEat BasophilsBananas

Leukocytes Cont’d Neutrophils - Majority of WBC’s, fight infection by phagocytosis (engulfing & swallowing germs). Elevated count indicates a bacterial infection (strep, staph, etc…) Lymphocytes - Provide immunity to the body by developing antibodies; protect against the formation of cancer cells. Monocytes - Phagocytize bacteria and foreign materials. Elevated count usually indicates a chronic (long-term) condition.

Leukocytes Cont’d Eosinophils - Attack parasites. Increase in response to allergic conditions (ex. allergic reaction, asthma, etc…) Basophils - Participate in the body’s inflammatory response; produce histamine (vasodilator) and heparin (anticoagulant)

Thrombocytes Thrombocytes (thromb/o = clot + -cyte = cell)  Also called platelets  Smallest formed elements in the blood  When blood vessel is damaged, platelets become sticky and clump together to form a clot

Blood Types- The ABO System  Four major types- A, B, AB, and O  Groups are based on whether A and/or B antigens are present on red blood cells  In type O, both A & B antigens are absent  In type AB, both A & B antigens are present

Blood type A has A antigens on the surface of RBC and B antibodies in the plasma

Blood type B has B antigens on the surface of RBC and A antibodies in the plasma

Type 0 has NO A or B antigens on the surface of RBC and they have BOTH A and B antibodies in the plasma

Type AB blood has BOTH A and B antigens of the surface of RBC and NO A or B antibodies in the plasma

Blood Types Cont‘d. Blood TypeCan Donate To Can Receive From AA, ABA, O BB, ABB, O AB (universal recipient) ABA, B, AB, O O (universal donor) A, B, AB, OO (only)

Blood Types- The ABO System

 Which blood type would be considered the “universal donor”?  Which blood type would be considered the “universal recipient”?

RH Factor  People are either Rh positive or Rh negative If you are Rh positive, you have the Rh antigen If you are Rh negative, you do not have the Rh antigen  It is important to know Blood Type and Rh Factor if a patient is going to receive blood.

PRACTICE TIME Perform the following tasks with your paper RBCs, antigens, and antibodies. 1. Create a blood type. 2. Find a table partner with a compatible blood type. 3. Find a table partner with an incompatible blood type.

Blood Vessels Three major types of blood vessels: arteries, veins, and capillaries.  Arteries (arteri/o) Large blood vessels that carry blood away from the heart. The aorta is the largest artery in the body, begins in the left ventricle Coronary arteries (coron/o) supply the heart with blood Pulmonary arteries - carry blood from the heart to the lungs Arterioles are thinner branches, carry blood to capillaries

Blood Vessels  Capillaries (capill/o) Blood vessels that connect arteries and veins to each other Smallest vessels in the body Blood flow is slower through capillaries; allows time for exchange of oxygen, nutrients, and waste products between surrounding cells and fluids

Blood Vessels  Veins (phleb/o, ven/o) Responsible for carrying waste-filled blood back to the heart Veins have valves that allow for one-way blood flow toward the heart Venules are the small veins that join to form larger veins.

Blood System Disorders  Anemia Lower than normal number of red blood cells  Iron Deficiency Anemia Develops if not enough iron is available to the bone marrow to make hemoglobin. Caused by inadequate iron intake, pregnancy, breast feeding, or chronic (long-term) blood loss.

Blood System Disorders  Aneurysm Weak spot in the wall of an artery, causes it to balloon out and sometimes rupture (usually fatal due to blood loss)  Arteriosclerosis (arteri/o=artery + sclerosis=hardening) Hardening of the arteries which reduces blood flow through the artery, usually a result of aging

Blood System Disorders  Varicose Veins Abnormally swollen veins usually occurring in the legs  Thrombus Blood clot attached to inside wall of vein or artery  Embolus Blood, air, fat or other substance circulating in the bloodstream. An embolism would be the blockage of the blood vessel by the embolus.

Blood System Disorders  Leukemia (leuk/o = white +emia = blood condition) Progressive increase in the number of abnormal leukocytes; malignant (harmful) disorder  Sickle Cell Anemia Genetic disorder that causes abnormal hemoglobin Abnormally shaped red blood cells (sickled instead of round) Interferes with normal blood flow through the body

Diagnostic Tests Pulse Oximeter External monitor that is applied to the finger to measure the level of oxygen in arterial blood Normal is above 96% Arterial Blood Gases Measurement of gases and ph of the blood. Measures the gases dissolved in liquid part of blood Blood gases include oxygen, carbon dioxide and nitrogen

Treatments/Procedures Medications  Statins Used to lower bad cholesterol and raise good cholesterol Examples - Lipitor, Vytorin, Zocor, Pravachol (have you seen commercials??)  Anticoagulants Slows blood clotting and prevents new clots from forming Examples - aspirin, coumadin, heparin, plavix

Treatments/Procedures Medications (cont’d)  Tissue Plasminogen Activator (tPA) –Clot dissolving enzyme used for immediate treatment of heart attack and stroke victims. –Breaks down the clot which reduces the damage to the heart (in heart attacks) and brain (in stroke patients) –Many billboards and commercials relating to prompt treatment for heart attacks and strokes. Aimed at encouraging patients to seek treatment quickly so drugs can be effective.

Treatments/Procedures Blood Transfusions  Transfusing whole blood or blood components (packed cells, plasma,…) into a patient.  The blood must be carefully matched (A,B, AB, or O as well as Rh factor) or the patient may suffer a severe reaction.  Blood is tested for diseases like HIV and Hepatitis before transfusion so the disease is not spread to the recipient of the blood.

Career Opportunities Hematologist (hemat/o = blood + -ologist = specialist) Specializes and treats disorders of the blood Phlebotomist Takes patient blood samples and prepares them for testing in the lab Medical Laboratory Technologist (MT) Works under the supervision of pathologist to study tissue, fluids, and cells in the human body Medical Laboratory Assistant Prepares specimens for testing, helps clean and maintain laboratory equipment

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