Chapter 17- Study Outline (Blood)
4. Describe the structure, function, and production of erythrocytes.
-Red Blood Cells (RBC's) -no nucleus -biconcave discs -picks up oxygen in capillary beds of the lungs and releases it to tissue cells across the body -job is to transport respiratory gases (O2, CO2) -ideally suited for gas exchange -97% hemoglobin (oxygen is bound to hemoglobin molecules) -lack mitochondria, generate ATP by anerobic mechanisms. -hormone erythroproietin (kidney) stimulates RBC -hematopoiesis- blood cell formation (occurs in red bone marrow) -Begins with hemocytoblast, then reticulocytes and finally erythrocytes.
7. List the classes, structural characteristics, and functions of leukocytes.
-granulocytes: phagocytic --neutrophils: multilobed nucleus (3) --eosinophils: bilobed nucleus (red-2) --basophils: biloboed nucleus pick up dyes (blue-granules large) -agranulocytes: no visible granules; nucleus is round or u-shaped --lymphocytes:thin outer layer; large nucleus --monocytes: nucleus u or kidney shaped; light cytoplasm "shape of an M?" Never Let Monkeys Eat Bananas Leukocytes(WBC's)- are crucial to our defense against disease, less than 1% of total blood
3. Discuss the composition and functions of plasma.
-other than 45% -water is main content -dissolved solutes in water --plasma proteins ---albumin (60%):regulation of circulatory system ---globulins: antibodies in plasma ---fibrinogen:forms fibrin threads in blood clot --electrolytes: help to maintain plasma osmotic pressure and normal blood pH
1. Describe the composition and physical characteristics of whole blood. Explain why it is classified as a connective tissue.
-red, sticky, salty -pH: 7.4 (7.35-7.45) H+ ions -temp: 39'C/100.4'F -serum (no fibers) -plasma (has fibers) --formed elements (r&w) ---rbc: hematocrit (45%) rbc blood is the only fluid tissue in the body. has both cellular and liquid components. is a specialized type of connective tissue in which living blood cells, called the formed elements, are suspended in a nonliving fluid matrix called plasma. the collagen and elastic fibers typical of other connective tissues are absent from blood, but dissolved fibrous proteins become visible as fibrin strands during blood clottine
2. List eight functions of blood.
1. Transport- delivering oxygen from the lungs and nutrients from the digestive tract to all body cells 2. Transport- transporting metabolic wastes from cells to elimination sites, (lungs CO2, kidneys nitrogenous waste in urine) 3. Transport- transports hormones 4. Regulation- Maintaining app. body temp 5. Regulation- Maintaining normal pH in body tissues 6. Regulation- Blood proteins prevent excessive fluid loss 7. Protection- prevents blood loss 8. Protection- prevents infection
15. Explain the diagnostic importance of blood testing.
A laboratory examination of blood yields information that can be used to evaluate a person's current state of health
6. Give examples of disorders caused by abnormalities of erythrocytes. Explain what goes wrong in each disorder.
Anemias Sickle Cell - Mutation affecting the AA sequence of the beta chains in the Hb Thalassemia - Inability to produce adequate amounts of alpha or beta chains of Hb Pernicious anemia - Inability to absorb enough ingested vitamin B12 due to a deficiency of intrinsic factor Nutritional anemia - not enough nutition Aplastic anemia - failure of bone marrow to produce enough RBCs. Hemolytic anemia - rupture/hemolysis of too many RBCs Polycythemia - abnormal excess of RBC Primary - tumor of bone marrow Secondary - adaptive mechanism, living at high altitude.
5. Describe the chemical makeup of hemoglobin.
Hemoglobin - 4 chains, 2 alpha, and 2 beta. Each RBC contains 250-280 Hb molecules Oxygen binds to Iron Carbondioxide binds to Amino Acids
11. Describe the processes of hemostasis. List factors that limit clot formation and prevent undesirable clotting.
Hemostasis- stops bleeding 1. vascular spasm - In the first step of blood vessel repair, the damaged blood vessels respond to injury by constricting (vasoconstriction), triggers include direct injury to vascular smooth muscle, chemicals released by endothelial cells and platelets, and reflexes initiated by local pain receptors. 2. Platelet Plug Formation - the second step of blood vessel repair, platelets play a key role in hemostasis by aggregating (sticking together), forming a plug that temporarily seals the break in the vessel wall 3. Coagulation - The third step in blood vessel repair, blood clotting, reinforces the platelet plug with fibrin threads that act as a "molecular glue" for the aggregated platelets **Factors that limit clot growth or formation** -Antithrombin III(a proetin present in plasma, quickly inactives any thrombin not bound to fibrin) and Heparin (natural anticoagulant contains basophil and mast cell granules) Heparin - Released by basophils and mast cells. accelerates the activation of antithromin-III Aspirin - inhibits thromboxane A2 and prostaglandins preventing platelet aggregation Protacyclin - opposes stimulatory action of thrombin, ADP and other factors
9. Give examples of leukocyte disorders, and explain what goes wrong in each disorder.
Leukopenia - low WBC Leukocytosis - Elevated Leukocyte count Leukemias - clones of a single WBC that remain unspecialized and grow out of control -Acute, Chronic, Myeloid, Lymphocytic Infectious Mononucleosis
8. Describe how leukocytes are produced.
Leukopoiesis: The production of white blood cells, is stimulated by chemical messengers. These messengers, which can act either as paracrines or hormones, are glycoproteins that fall into two families of hematopoietic factors, interleukins and colony-stimulating factors, or CSFs. are named for the leukocyte population they stimulate
14. Describe fluids used to replace blood volume and the circumstances for their use.
When a patient's blood volume is so low that death from shock is imminent, there may not be time to type blood, or appropriate whole blood may be unavailable. Such emergencies demand that blood volume be replaced immediately to restore adequate circulation. Fundamentally, blood consists of proteins and cells suspended in a salt solution. Replacing lost blood volume essentially consists of replacing that isotonic salt solution. Normal saline or a multiple electrolyte solution that mimics the electrolyte composition of plasma (for example, Ringer's solution) are the preferred choices.
Formed elements
erythrocytes, leukocytes, platelets (RBC's) (WBC's)
13. Describe the ABO and Rh blood groups. Explain the basis of transfusion reactions.
•Blood types has a classification which is based on two things: ABO group - depends on two antigens; antigen A and antigen B. which lie on the surface of the red blood cell (RBC) A person having an A antigen on his RBC cells will show a blood type of A A person having a B antigen on his RBC cells will show a blood type of B A person having both A & B antigens on his RBC cells will show a blood type of AB A person having neither of those antigens will show a blood type of O Rhesus factor - the rhesus factor, which depends on a single antigen; antigen D, which also lies on the surface of the RBC A person having a D antigen is called an Rh positive, e.g. A, B and D antigens' presence exhibit a blood type of AB+ (universal acceptor) A person without the D antigen is called an Rh negative, e.g. Neither A, nor B, nor D antigens' presence exhibit a blood type of O- (universal donor). Both factors combine to form the blood types as we know them today •if you transfuse type B blood cells into a type A person then that persons immune system won't recognise the type B antigens as part of the body and will attack them just as it would invading bacteria. Transfusion reactions can range from the mild such as a fever too the more serious such as lung injury and acute heamolytic reaction where donor red cell are rapidly destroyed which is bad. (life threatening medical emergency bad)
10. Describe the structure and function of platelets.
•Platelets are not cells in the strict sense. About one-fourth the diameter of a lymphocyte, they are cytoplasmic fragments of extraordinarily large cells (up to 60 μm in diameter) called megakaryocytes •Platelets are essential for the clotting process that occurs in plasma when blood vessels are ruptured or their lining is injured. By sticking to the damaged site, platelets form a temporary plug that helps seal the break
12. Give examples of hemostatic disorders. Indicate the cause of each condition.
•Thromboembolic disorders-conditions that cause undesirable clot formation •Bleeding disorders-arise from abnormalities that prevent normal clot formation -Thrombocytopenia (low number of circulating platelets -Impaired liver functions -Hemophilias (several hereditary bleeding disorders) •Disseminated Intravascular Coagulation (DIC)- involves both wide spread clotting and severe bleeding