Chapter 19 questions
Describe the formation of platelets from pluripotent stem cells, including the influence of hormones.
-Derived from mesenchyme -produce myeloid stem cells which differentiate into progenitor cells some are known as CFU's -hemopoietic growth factors regulate differentiation into particular progenitor cells -CFU-Meg- produces megakaryoblast--->megakaryocyte--->platelets
What substances does blood transport?
-O2 from lungs to cells of the body -CO2 from body cells to lungs for exhalation -nutrients from GI tract to body cells and hormones from endocrine glands to other body cells -heat and waste products to various organs for elimination
What is erythropoeisis? How does it effect hematocrit? What factors speed it up and slow it down?
-Production of RBC starts in red bone marrow with proerythroblast -normally destruction and creation occurs at the same rate -speeding up or slowing down is caused by cellular oxygen deficiency, hypoxia, anemia (lack of iron, amino acids, and vitamin B12), stimulates increase of RBC's
How is hemoglobin recycled?
-macrophages phagocytize ruptured and worn out blood vessels -globulin and heme are split apart -globulin is broken into amino acids, allowing them to be reused for other proteins -Iron is removed from heme, which associates w/ transferrin, transports iron in the bloodstream -in muscle fibers, liver cells, and macrophages, of spleen and liver, iron detaches from transferrin and attaches to the iron storage molecule ferrintin -once released from storage site or absorption from GI tract, iron reattaches to transferrin -iron transferrin complex carried to red bone marrow where RBC precursor cells take it up through receptor cell mediated endocytosis to use in hemoglobin synthesis -iron needed for hemoglobin, amino acids for globulin and vitamin B12 -erythropoiesis in red bone marrow makes RBC's which enter circulation
What is hemostasis?
-sequence of responses that stop bleeding reduced blood loss by: 1. vascular spasm 2.platelet plug formation 3. blood clotting (coagulation) *prevents hemorrhage from small vessels
How many kilograms or pounds of blood are there in your body?
8% of your body weight
What is agglutination?
Agglutination refers to the clumping of red blood cells.
List the formed elements in the blood plasma and describe their functions.
Albumins-smallest, most abundant-maintain osmotic pressure, exchanging fluids across capillary walls Globulins-large(immunoglobulins)-attack viruses and bacteria. Alpha beta globulins transport irons, lipids, and fat soluble vitamins. Fibrinogen-essential in blood clotting
Along with platelet plug formation, which two mechanisms contribute to homeostasis?
Along with platelet plug formation, vascular spasm and blood clotting contribute to homeostasis.
Why is the firstborn baby unlikely to have HDN?
Because the mother is most likely to start making anti-Rh antibodies after the first baby is already born, that baby suffers no damage.
Describe the size, microscopic appearance, and functions of RBC's.
Biconcave disks with a 7-8 micrometer diameter -strong and flexible plasma membrane -lack a nucleus and other organelles, cannot reproduce or carry on extensive metabolic activities -cytosol contains hemoglobin molecules, 33% of its weight -transport O2, generate ATP anaerobically -good shape for diffusion -contains 280 million hemoglobin molecules/cell -composed of 4 polypeptide chains one iron in the center, each hemoglobin can bind to 4 O2 molecules -transports 23% CO2 in body -lives 120 days -carbonic anhydrase-CO2 and H2O to carbonic acid
What is the approximate volume of blood in your body?
Blood volume is about 8% of your body mass, roughly 5-6 liters in males and 4-5 liters in females.
What is fibrinolysis? Why does blood rarely remain clotted inside blood vessels?
Dissolution of a blood clot, once plasmin is formed it can dissolve the clot by digesting fibrin threads and inactivating substances such as fibrinogen, prothrombin, and factors V and VII. Throbin has a positive feedback although clotting remains localized -blood rarely remains clotted because of anticoagulants including antithrombin, heparine, activated protein C etc
Which hemopoietic growth factors regulate differentiation and proliferation of CFU-E and formation of platelets from megakaryocytes?
Erythrocytes vs. megakaryocytes Erythrocytes develop into RBC's and Megakaryocytes develop into platelets
How do extrinsic and intrinsic pathways of blood clotting differ?
Extrinsic-much faster, fewer steps, prothrombinase released from the surface of damaged cells complex mixture of lipoproteins and phospholipids which activates the clotting factor X. Intrinsic-more complex, occurs more slowly, series of reactions eventually activating clotting factor X
How does the volume of blood plasma in your body compare to the volume of fluid in a 2-liter coke bottle?
Its a little more than a 2-liter bottle of just blood plasma which makes up 55% of your total blood volume, differing depending on male/female.
In what way is the "traffic pattern" of lymphocytes in the body different from that of other WBCs?
Lymphocytes recirculate from blood to tissues and back to blood. After leaving the blood, other WBC's remain in the tissues until they die.
Which WBC's are called granular leukocytes? Why?
Neutrophils, eosinophils, and basophils are called granular leukocytes because all have cytoplasmic granules that are visible through a light microscope when stained.
How might your hematocrit change if you moved from a town at sea level to a high mountain village?
Once you move to high altitude, your hematocrit would increase due to increased secretion of erythropoetin.
How many molecules of O2 can one hemoglobin molecule transport?
One hemoglobin molecule can transport a maximum of 4 O2 molecules, one O2 bound to each heme group.
Which formed elements of the blood are cell fragments?
Platelets are cell fragments.
From which connective tissue cells do pluripotent stem cells develop?
Pluripotent stem cells develop from mesenchyme.
How to RBC's, WBC's, and platelets compare with respect to size, number per microliter of blood, and life span?
RBC's-7-8 micrometers, 4.8-5.4 million/microliter, live 120 days WBC's-5,000-10,000 per microliter, live for a few hours or days platelets-2-4 micrometers, 150k-400k/microliter, live 5-9 days
What is serum?
Serum is blood plasma minus the clotting proteins.
What are some symptoms of sickle cell disease?
Some symptoms of sickle-cell disease are anemia, jaundice, bone pain, shortness of breath, rapid heart rate, abdominal pain, and fatigue.
What is the outcome of the first stage of blood clotting?
The outcome of the first stage of clotting is the formation of prothrombinase.
What precautions must be taken before giving a blood transfusion?
The person must be blood typed and checked for the Rh blood group
In what ways is blood plasma similar to intersticial fluid? How does it differ?
They are both fluids, blood is a connective tissue in an extracellular matrix of blood plasma and cell fragments. Intersticial fluid is the fluid that bathes body cells which is renewed by the blood. -Blood-->O2--->lungs, GI tract ect-->intersticial fluid----> cells -CO2, waste--->body cells--->intersticial fluid--> blood--> organs of the body
What is the function of transferrin?
Transferrin is a plasma protein that transports iron in the blood.
Which antibodies are usually present in type O blood?
Type O blood contains both anti-A and anti-B antibodies.
What is a differential white blood cell count?
a count of the 5 types of WBC's to detect infection or inflammation, ex poisoning or possible drugs, monitor blood disorders, effects of chemo, allergic reactions, and parasitic infections ex. difference between high and low WBC counts based on the percentages that should be there
Define the following: anticoagulant, thrombus, embolus, and thrombolytic agent.
anticoagulant-substance that delay, suppress, or prevent blood clotting thrombus-a blood clot itself embolus-blood clot, bubble of air, fat from broken bones, piece of debris transported by the bloodstream thrombolytic agent-chemical substances that are injected into the body to dissolve blood clots tat have already formed to restore circulation, directly or indirectly activate plasminogen
What is the importance of emigration, chemotaxis, and phagocytosis in fighting bacterial invaders?
emigration-AKA diapdesis-RBC's roll along the endothelium, stick to it, then squeeze between endothelial cells with the help of adhesion molecules ex. selectins that respond to nearby injury and inflammation, on neutrophils-selectins stick to carbs on their surface, known as integrins which tether the neutrophil to the endothelium and assist their movement through the blood vessel wall and into intersticial fluid phagocytosis-neutrophils and macrophages, ingest bacteria and dipose of dead matter chemotaxis-chemicals released by microbes and inflamed tissues attract phagocytes among these are, colony stimulating factors and kinins produced by microbes
What functions do granular leukocytes, macrophages, B cells, T cells, and natural killer cells perform?
leukocytes-combat pathogens and foreign substances that enter the body macrophages-gather at sites of inflammation or infection B cells-secrete antibodies T cells-attack invading viruses Natural Killer cells-attack wide variety of infectious microbes and certain spontaneously arising tumors
How are leukocytosis and leukopenia different?
leukocytosis-increase in the number of WBC about 10,000 per microliter in response to stress ex invading microbes, strenuous exercise, anesthesia, and surgery leukopenia-abnormally low, never beneficial, can be caused by radiation, shock, or chemotheraputic agents
What is hemolysis, and how can it occur after a mismatched blood transfusion?
rupture of the RBC's and release of hemoglobin into the blood plasma After a transfusion antibodies can attach to antigens and cause agglutation and hemolysis of the red blood cells Or antigens can attach to the recipients red blood cells and cause dilution of antibodies not causing significant harm
What is the significance of lower-than-normal or higher-than-normal hematocrit?
significant drop indicates anemia higher than normal-higher blood viscosity, high blood pressure, increased risk of stroke, tissue hypoxia
How are cord-blood transplants and bone marrow transplants similar? How do they differ?
similar-treat types of cancer cord blood-more abundant stem cells than red bone marrow, less likely to cause graft-versus host disease, so the match does not have to be as close, larger number of donors, less likely to transmit infections, can be stored indefinitely in cord blood banks
Explain the conditions that may cause hemolytic disease of the newborn.
small amount of Rh+ blood leaks from the fetus through the placenta into the blood stream of an Rh- mother, the mother will start to make Rh antibodies during a second pregnancy the maternal antibodies cross the placenta into the fetal blood, if the fetus is Rh+, the antigen-antibody causes aggulation and hemolysis of the RBCs.
How do vascular spasm and platelet plug formation occur?
vascular spasm: arterioles or arteries that are damaged, their smooth muscle contracts immediately reducing blood loss for several minutes to hours, activated platelets and pain receptors induce this response platelet plug formation: 1.platelets stick to damaged area-platelet adhesion 2. platelet release reaction-activating nearby platelets making others very sticky-platelet aggregation, large numbers eventually form a platelet plug
