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171 Cards in this Set
- Front
- Back
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What is blood? Characteristics?
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-complex tissue consisting of cells suspended in fluid (plasma)
-pH range- 7.35-7.45 -volume: normovolemia vs hypovolemia vs hypervolemia -viscosity- approx. 3 x H20 |
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What is the composition of blood?
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-45% cells (RBCs, platelets, and WBCs)
-55% plasma |
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What is Hematopoieis?
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-producton of blood cells
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What is the precursor cell for hematopoeisis?
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-pluripotent hematopoeitic stem cell
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What is the relationship between hematopoeisis and age?
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-the production of red blood cells decrease as one increases with age
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What s the dfference between red and yellow bone marrow?
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-red bone marrow s actve, due to the presence of hemglobn
-yeloow bone marrow s nactve due to the adunace of adipocytes |
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What is the sturcture of bone marrow?
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-well vascularized
-has hematopoeitic space -has sinuses -has central vein |
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How are blood cells developed?
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-derived from pluripotent hematopoeitic stem cells
-become "uncommitted" precursors -conduct self-renewal for differentiation |
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How is differentiation of blood cells regulated?
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-by hematopoeitic growth factors
-can be multilineage or specific |
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What are examples of multilineage differentiated cells?
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multilineage: stem cell factor (SCF), various interleukins (ILs), granulocyte-macrophage colony-stimulating factor (GM-CSF)
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What are examples of specific cell differentiation hormones?
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-granulocyte colony stimulating factor (G-CSF)
-monocyte colony stimulating factor (M-CSF) -erythropoeitin (Epo) thrombopoeitin (Tpo) |
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How are growth factors secreted?
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-by accessory cells in bone marrow
-by non-hematopoeitic organs -by T-lymphocytes |
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What is the precursor to erythrocytes? Platelets? netrophils and macrophages? eosinophils? basophils?
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-colony forming unity erythrocyte (CFU-E)
-colony formingh unit megakaryocyte (CFU-Mega) -colony fomring unity granulocyte-macrophage (CFU-GM) -colony form,ing unit eosinophil (CFU-EO) -colony forming unity basophul (CFU-Bas) |
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What is mature red blood cell function? Morphology?
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-O2 transport
-uniform size and shape -highly flexible -no internal organelles |
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What is reticulocyte count?
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-percentaghe of retuclocytes in circulating RBCs
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What is hematocrit?
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-volume of RBCs/totoal volume of blood
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What is hemoglobin content?
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-average hemoglobin content in 1 dl of blood
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What is mean cell volume?
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-average volume of an RBC
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What is mean cell hemoglobin content?
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-average hemoglobin content in 1 dl RBCs
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What is the role of erythropoeitin?
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-glycoprotein with 165 amino acids
-produced in the kidneys of adults -stimulates differentiation of RBC precursors in bone marrow -regulated by O2 concentration in blood |
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Why does Epo synthesis increase in response to decrease in O2 levels?
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-blood loss
-higher altitude -pulmonary disease -low hemoglobin content -Epo synthesis returns to normal when O2 levels are restored |
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Othere than Erythropoeitin, what is needed for red blood cell development in bone marrow?
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-vitamin B12, folic acid, and iron
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What occurs when cells divide and differentiate?
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-size decreases at each step
-hemoglobin synthesized -internal organs lost -final step occurs in circulation (reticulocytes--> erythrocytes) |
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What is hemoglobin? What are the 3 types?
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-a tetrameric protein
-HbA: 2 alpha + 2 beta= 95-98% -HbA2: 2 alpha+ 2 delta= 2-3%\ -HBF: 2 alpha+ 2 gamma= <2% |
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What binds to hemoglobin?
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-oxygen reversibly binds to iron at center of heme group (1/peptide chain)
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How is iron absorbed?
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-from dietary sources
-uptake via active transport -binds to apotranferrin in blood--> tranferin -distributed into Hb and other sites |
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How is iron distributed from the plasma?
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-goes to myoglobin,cytochromes, etc
-goes to liver to bind to apoferritin-->ferritin -goes o bone marrow to bind to ferritin-->hemoglobin |
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What is the average daily loss of iron in men and women?
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-.5-1 mg
-1-2 mg |
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How does hemoglobin synthesis occur?
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-occurs in RBC precursors
-active uptake of iron-tranferrin complex -heme groups synthesized in mitochondria/cytosol -peptide chains synthesized -excess iron stored in ferritin -apotransferrin gets recycled out of cytosol |
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How do erythrocytes get destroyed?
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-blood empties into red pulp of spleen
-RBC's pass through pores -old RBCs are not flexible and become trapped -destroyed by splenic macrophages |
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What occurs during degradation of hemoglobin?
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-iron and amino acids are reused by body
-heme groups aren;t reused -degraded by splenic macrophages -transported to liver for further metabolism -bilirubin excreted in feces |
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What is anemia?
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-decrease in RBC count or hemoglobin content of blood
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what are symptoms of anemia?
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-mild cases-aymptomatic
-may be subtle -any or all organs may be affected (CNS, cardiovascular, respiratory) -fatigue, loss of libido, pagophagia, geophagia, etc |
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what is hemolytic anemia?
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-increase destruction or loss
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What is the hypoproliferative anemia?
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-decrease in production of hemoglobin
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What is RBC morphology of megaloblastic anemia?
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-macrocytic
-normochromic 103-160 MCV 32-36 MCHC |
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What is RBC morphology of blood loss anemia?
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-normocytic
-normochromic 82-103 MCV 32-36 MCHC |
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What is the RBC morphology of iron deficiency anemia?
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-microcytic
-hypochromic 60-82 MCV 20-30 MCHC |
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What are hemolytic anemias?
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-blood loss anemias
-megaloblastic anemias |
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What are blood loss anemias?
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-follows hemorrhaging
-due to injury, surgery -plasma and blood replaced rapidly |
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What are megaloblastic anemias?
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-megaloblasts present in circulation, also nuclei
-increases MCV -often associated with vitamin B12 or folic acid deficiency -results from defect in erythropoiesis -hemolysis occurs |
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What is glucose-6dehydrogenase (G6PDH) deficiency related anemias?
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-G6PDH indirectly helps protect RBCs against oxidative damage
-inherited deficencies can predispose an individual to RBC hemolysis -usually associated with certain drugs |
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What is sickle cell anemia?
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-defective hemoglobin (HbS)-->preciopitates and polymerizes when deoxygenated
-RBCs are prematurey destroyed-->anemia and tissue damage |
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What is hypoproliferative anemias?
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-iron deficiency anemias
-aplastic anemias |
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What is iron deficency anemias?
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-may develope slowly
-results from poor diet, pregnancy, etc. -dec. in erythropoeisis |
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What is aplastic anemias?
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-due to destruction of stem cells
-decrease in all blood cell lines can result in death -may result from drugs and radiation overdose |
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What is polycythemia?
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-increase in RBC count or hemoglobin content in blood
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What is polycythemia vera?
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-due to excessive erythropoiesis
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What is secondary polycythemia?
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-increased RBC count due to tissue hypoxia
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What are the physiological effects of polycythemia?
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-circulatory system-increasd Hct, blood volume, and blood viscosity
-enlarges spleen, change in skin color, etc |
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What is platelet function and morphology?
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-hemostasis
-smallest blood cell -150000-350000 per uL blood |
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What is thrombopoiesis?
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-production of platelets (throbocytes)
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What is required for throbopoeisis?
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-need multilineage gorwth factors (IL-3, GM-CSF, etc)
-need throbopoietin (TPO) |
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Where are platelets produced and the pathway for their production?
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-in bone marrow from megakaryocytes--> cytoplasmic fragments-->platelets
-released into sinuses |
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What is the role of thrombopoietin?
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-glycoprotein with 332 amino acids (MW~70,000
-stimulates differentiation in bone marrow -constituitvly synthesized by liver in both fetus and adult |
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What is an anticoagulant?
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-prevents blood clots
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How is a blood clot formed?
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-procoagulants activated
-activated by damaged subendothelium (change shape and secrete ADP and thromboxane A2 (TXA2)) -platelet aggregationa nd adhesion occurs -fibrin monomers becomes fibrin strands -Fibrin stabilizing factor catalyses cross linking of fibrin strands -retraction forms blood clot |
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What are platelet glycoprotein receptors?
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-prevent shearing of platelet plug from vessel wal
-exposed by activated platelets |
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What are the platelet glycoprotein receptors?
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-GPIb-IX-V links oplatelets to collagen via von Willebrand's factor (vWF)
-GPIIb-IIIa links platelets to fibrogen |
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How is fibrin formed?
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-formed from fibrinogen
-inactive plasma protein\ -non-enzymat9ically (spontanously) polymerizes |
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How is Thrombin formed?
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-formed from prothrombin (inactive plasma protein)
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How is prothrombin activator produced?
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-by coagulation cascade
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What is thrombin in the coagulation cascade?
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-activates positive feedback loop
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What vitamins and minerals are needed for the coagulation cascade?
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-calcium required for direct role in several steps
-vitamin K required (indirect role) |
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What is the relevence of contact activation?
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-effect of factor XII deficiency
-TF/VIIa activates factor IX |
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What is the extrinsic pathway of the coagulation cascade?
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-tissue factor (TF) exposed on surface of damaged endothelial cells
-factor VII binds to TF and becomes activated -TF/VIIa complex activates factor X (common pathway) |
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What is the intrinsic pathway of the coagulation cascade?
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-contact with collagen activates factor XII ("contact activation")
-factor XIIa activates factor XI, factor XIa then activates factor IX -factor IXa combines with factor VIIIa -IXa/VIIIa complex activates factor X (common pathway) |
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What is the common pathway of the coagulation cascade?
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-factor V binds to platelet surface and is activated
-factor Xa combines with factgor Va and lipids to form prothrombin activator -thrombin is generated and converts fibrinogen to fibrin |
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What is significant about thrombin in the coagulatuion cascade?
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-stimulates its own formation by activating factors V, VIII, and XI
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What is vitamin K needed for synthesis of?
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-factors VII,IX, X, and prothrombin
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What are the physiological factors of the regulation of blood clotting?
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-smooth vascular endothelium prevents "accidental" activation
-dilution of clotting factors slow blood flow--> activation -clotting factors must be activated (activated when needed) -localization of coagulation cascade (components generated in clot |
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What are the anticoagulants?
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-antithrombin III (plasma protein)
-heparin (polysaccharide) -tissue factor pathway inhibitor (TFPI) -thrombomodulin -prostacyclin (PGI2) -nitric oxide |
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What does antithrombin III do?
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inactivates thrombin and factor Xa
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What does heparin do?
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-interacts with antithrombin III
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What does tissue factor pathway inhibitor do?
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inactivates TF/VIIa complex
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What does thrombomodulin do?
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-released by undamaged endothelial cells near injury
-thrombin binds to thrombomodulin and activates protein C -activated protein C/protein S inactivates Va and VIIIa -stimulates release of tissue plasminogen activator (tPA) |
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What does prostacyclin do?
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-inhibits platelet aggregation and induces vasodilation
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What does nitric oxide do?
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-inhibits platelet adhesion/aggregation and induces vasodilation
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What is the mechanism of the dissolution of a blood clot?
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-plasminogen is trapped in clot
-converted to plasmin by several different activators (tPA, uPA, factors XIIa and XIa) -plasmin enzymatically digests fibrin fibers -clot dissolves |
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What activates clot degradation?
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-tissue plasminogen activator (tPA)
-urokinase plasminogen activator (uPA) -factors XIIa and XIa |
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How is fibrinolysis (clot degradation) regulated?
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-plasminogen activator inhibitor-1 (PAI-1) inactivates tPA and uPA
-activity of plasmin is inhibited by alpha-2 antiplasmin |
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What is thrombocytopenia?
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-decrease in circulating levels of platelets (<50,000)
-prone to bleeding from small capillaries -causative agents (drugs, aplastic anemia, etc) |
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What is vitamin K deficiency?
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-vitamin K must be absorbed (digested by dietary.intestinal bacteria)
-required for synthesis of several clotting factors/prothrombin -deficency results in synthesis of non-functional clotting factors (causes decreased GI absorption) |
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What is hemophilia?
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-inherited deficency of factor VIII or IX
-excessive bleeding may occur following minor injury -organ damage may result |
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What is thromboembolism?
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-abnormal blood clot (thrombus) can form and break free
-free-floating clots (emboli) may plug blood vessels -massvie tissue damage from hypoxia |
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What is disseminated intravascular clotting?
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-widespread, uncontrolled clotting
-associated with certain bacterial infections, snake bites, etc -possible high mortality rate |
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What are the 3 types of leukocytes?
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-graulocytes
-monocytes/macrophages -lymphocytes |
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What are neutrophils?
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-4300 cells/uL
-live for hours-days -has nonpspecific immunity (bacteria and viruses) |
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What are lymphocytes?
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-2700 cells/uL
-live for years -has specific immunity (bacteria and viruses) -surveillance (tumor cells) |
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What are monocytes and macrophages?
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-500 cells/uL
-non-specific immunity (bacteria and viruses) |
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What are eosinophils?
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-230 cells/uL
-non-specific immunity (parasites) |
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What are basophils?
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-40 cells/uL
-allergies |
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How are leukocytes produced?
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-derived from stem cells
-process controlled by growth factors |
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What growth factors control the production of leukocytes? Specifc examples?
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-interleukins (ie.-IL-3)
-GM-CSF: granulocytes and monocytes -G-CSF: granulocytes (neutrophils) M-CSF: monocytes (macrophages) |
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What is the mechanism of the marrow reserve?
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-activated macrophages secrete CSFs
-effects leukocytes in bone marrow through production and/or release |
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What is neutropenia (agranulocytosis)?
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-decrease in circulating neutrophils
-due to defect in production -susceptibility to infection increased |
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What is leukemia?
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-increase in number of immature leukocytes
-myelogenous vs lymphogenous leukemias -due to uncontrolled production -demands on normal metabolism greatly increased |
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What is the differnce b/t myelogenous and lymphogenous leukemia?
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lymphogenous: type of leukemia affecting lymphoid tissue.
myelogenous: leukemia that affects bone marrow |
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What is the structure of the upper respiratory tract?
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-oral and nasal cavities, pharynx, and larynx
-Air conditioning (warming, humidification, and filtration |
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What is the structure of the lower respiratory tract?
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-trachea, bronchi-->alveoli (lungs) encased in pleura (fluid + membrane)
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What is the structure of the accessory structures?
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-skeeltal muslce,
-vasculature -sensors |
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What is the mechanism of air passign through the oral and nasal cavities?
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-air enters nasal cavity
-cilia push mucus -pharynx has resonator for mucus swallowed or coughed out -larynx uses cilia to push mucus up |
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How does a sneeze occur?
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-URT irritation-->spasmodic expiratory muscle contraction-->forceful expiration
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How does a cough occur?
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-forceful exhalation preceded preliminary inspiration (alos uses expiratory muscles)
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How do hiccups occur?
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-spasmodic, periodic closure of glottis and spastic diaphram
contraction |
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How do snores occur?
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-air passage narrowed upper passageway
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What are the characteristics of trachea?
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- only 1 exists
-has cilia -has smooth muscle -has cartilage |
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What are the characteristics of bronchi?
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-have 2-8
-has cilia -has smooth muscle -has patchy cartilage |
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What are the characteristics of bronchioles?
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- have 8-12
-has cilia -has smooth muscle -has no cartilage |
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What are the characteristics of respiratory bronchioles?
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-have up to 25
-has some cilia -has smoem smooth muscle -has no cartilage |
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What are the characteristics of alveiolar ducts?
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-600 million
-has no cilia -has some smooth muscle -has no cartilage |
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What are the characteristics of alveolar sacs?
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-600 million
-has no cilia -has no smooth muscle -has no cartilage |
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What are alveoli?
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-blind air-filled outpouchings
-tennis court sized surface area -has thin respiratory membrane for gas exchange (o2 in, CO2 out) |
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What is the diaphragm?
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-huge, dome-shaped skeletal muscle, attached to lower lung lobes
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What are the muscles involved in respiration?
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-diaphragm
-external and internal intercostals -scalenes and neck muscles -abdominal muscles |
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What is the vasculature of the respiratory system?
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-pulmonary arteries, veins, and capillaries
-bronchial cirulation includes systemic circulation, supports bronchioles, etc |
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What are the sensors of the respiratory system?
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-chemosensors and stretch receptors
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How do the muscles act during respiration?
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-diaphram pulls down during inhalation
-external intercostals pull ribs outward during inhalation -internal intercostals pull ribs together during exhalation -scalenes pull rib cage up in inhalation -abdominals pull contents up in exhalation |
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What is external respiration and how does it work?
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-ventilation via negative pressure pump
-diaphragm and external intercostal muscle contract causing negative intra-alveolar pressure -air flows down pressure gradietn into lungs -gas exchange occurs (perfusion) |
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What are type I alveoli?
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-gas exchange barrier
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What are type II alveoli?
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-secrete surfactant, tranport solutes
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What is surfactant?
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-surface active agent
-DPPC and other PL, proteins -reduce surface tension, stabilize alveoli |
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What are elastin fibers for during respiration?
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-recoil of alveoli
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What are pulmonary capillaries in respiration?
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-high flow, low pressure system
-hold 450 mL in volume, can shift 200-1000 mL -veins and arteries are short,thin walled (distensible) -lymphatis drain interstium, keep alveoli dry via negative intrapleural pressure (prevent edema) -Q pulm= Q sys (matches venitilation, hydrostatic pressure grad., CO changes, recruitment of capilarries) |
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What occurs when lung volume increases?
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expiration starts to plateu
-inspiration starts to rise |
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What are the gas laws of the respiratory system?
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-partial pressure= p atm x %gas (affected by humidity)
-gases move from high pressure to low pressure -diffusion across respiratory membrane affected by change in pressure, solubility (MW of gas), cross sectional area of alveoli, and distance |
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What is inspiration?
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-0-2 sec
-contraction of diaphram and external intercostals -causes negative change in pressure--> air flow |
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What is expiration?
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-2-4 seconds
-elastic recoil-->positive change in pressure--> air outflow -contraction of internal intercostals, abdominals too for rapid for forced expiration |
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What is alveolar ventilation?
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-real determinant for perfusion matching, gas trasnport
-amount of air reaching/leaving alveoli |
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What is dead space of alveolar ventilation?
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-no gas exchange
-anatomically airways before terminal bronchioles -physiologically damaged or edematous alveoli -normally Vd~150 mls |
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What is the rate of alveolar ventilation?
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-Va= freq x (Vt-Vd)
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How is the airway diameter regulated for control of ventilation?
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-sympathetics dilate via bronchiolar B2 adrenoreceptors
-parasympathetics constrict via muscarinic receptors -local factor such as histamine, bradykinin constrict |
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How does hypercapnia/acidic pH in ventilation occur?
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-due to hypoxia
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How does hypocapnia/basic pH occur?
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-hyperoxia
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What does spirometry do?
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-measures how much volume of air a person can hold in their lungs
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What are obstructive pulmonary diseases? Restrictive? What do they cause physiologically?
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-emphysema (loss of elastin), bronchitis (excess/thick mucus), and asthma (SMC hyperactivity and inflammation)
-RDS (decrease surfactant) and fibrosis (increase collagen) -leads tio dyspnea (altered volumes/capacities and altered breath sounds) -which leads to dec. FEV, inc. RV, dec. IRV, and whistling |
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What is the composition of alveolar air?
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-not the same as atmospheric
-only partial replacement with each breath humidified, mixed with "old" air -alveolar PO2= 104 mm Hg -alveolar PCO2= 40 mm Hg |
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How is oxygen trasported in respiration?
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- concentration pressure gradient driven
-lungs: from alveeoli into blood -tissues, from blood to tissue |
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How is CO2 transported in respiration?
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-small pressure diffeerenc, but high solubiltiy
-lungs: from blood into alveeoli tissues: from tissues into blood |
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What is the direction of flow for oxygen transport in respiration?
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-gas exchange occurs in alveoli
-oxygen goes to small arteries -thenb smnall capillaries -then intrstitual fluid -then cytosol -then mitochondria for usage |
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Why does oxygen transport need hemoglobin?
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-soluble at .3 mL O2/dL blood
-HB capacity is 20 mL O2/dL blood -HB is a tetrameric protein and one heme that binds O2 -Hb lso transports H+, CO2, 2,3 DPG, NO (different binding sites -CO--> O2 binding site, but 200x greater affinity |
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What is oxyhemoglobin?
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-Hb with 4 O2
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What is deoxyhemoglobin?
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-Hb with no O2
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What are the different form s of hemoglobin?
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-Adult= (HbA)
-Fetal (HbF) (higher affinity foir O2) -sicle cell Hb= HbS (abnormal B chains--> shaope change) -methemoglobin (metHb) (Fe2+-->Fe3+) |
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What does Hemoglobin carrying caapcity depend upon?
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-concentration of hemoglobin and oxygen pressure
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What are the effects of pH on Hb-O2 saturation?
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-lower pH leads to lower oxygen pressure
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What is the effect of temperature on Hemoglobin-oxygen saturation?
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-as temperature increases, oxygen pressure decreases
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What is the effect of CO2 pressure on hemoglobin-oxygen saturation?
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-as CO2 pressure increases, oxygen pressure decreases
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How is 2,3-DPG a glycolysis sensor?
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-glycolysis increass with anaerobic metabolism in Hypoxia (anemia, high altitude)
-as 2,3 DPG increases, there is less oxygen pressure |
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What are the factors that casue a decrease saturation of oxygen and increased pressure? Significance?
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-increased H+
-increased CO2 -increased temperature -increased 2,3 DPG -better delivery of oxygen to tissue |
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What are the factors that increase saturation of oxygen and decreased pressure? significance?
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=decreased hydrogen content, COI2, temperature, and 2,3 DPG
-better pickup by hmeoglobin |
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What is the effecgt of ADP on O2 use?
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-the more ADP, the more O2 use
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Why does carbon monoxide occur?
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-carbon monoxide has a higher affinity to hemoglobin than oxygen
-decreases th number of binding sites for O2 -increased rtentetion of already bound O2 |
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What is the movement of CO2 respuiration?
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-low pressure gradient, but high solubility drives CO2 transport
-moves from cytosol to interstitual fluid to alveoli for gas exchange |
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What molecules transoirt as CO2 from tissue to lungs?
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-70% HCO3
-23% HbCO2 -7% CO2 |
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What is tyhe role of carbonic anhydrase?
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-to transport CO2 from tissue to lungs
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What is hypoxic hypoxia?
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-low arterial PO2
-due to high altitude, hypoventiulastion, dcrased diffudsion, abnormal V/Q |
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What is anemic hypoxia?
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-low O2 bound to hemoglobin
-due to blood loss, low Hb or HBO2 binding, and CO poisioning |
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What is ischemia hypoxia?
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reduced Q (charge)
-due to heart failure, shock, and thrombosis |
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What is histotoxic hypoxia?
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-failure to use O2
- ue to cyanide and other metabolic poisons |
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How is respiration regulated by the respiratory center in the medulla and pons?
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-dorsal respiratory group for inspiration
-pneumotoxic center stops inspiration -apneustic center inhibits switch off of inspiration -ventral respiratory group--> inactive until need forced breathing enahces both inspiration and expiration |
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What is the Hering-Breuer reflex of control of respiratory center activity?
|
-stretch receptors in wall of bronchi and bronchioles
-too much stretch-->activates switch-off of respiratory ramp signal |
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What is the central chemical control of respiratory center activity? What are neurons sensitive to?
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-chemosensitive area of respiratory center--> increased respiration
-neurons sensitive to H (direct) and CO2 (indirect +H20-->H) -blood CO2 --> blood H becuase of greater crossing of BBB |
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What is the peripheral chemoreceptor control of respiratory center activity?
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-carotid, aortic bodies--> increased respiration
-sensitive to low oxigen pressure--> strong simulation -increased hydrogen or CO2--> strong stimulation |
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What is the relationship b/t CO2 and chemoreceptors?
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-plasma CO2 stimulates chemoreptors in order to decrease plasma CO2 and increase plasma O2
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What si the mechanism of peripheral chemoreceptors in the carotid body?
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-low O2 content leads to K+ closure
-cell depolarizes -voltage Ca2+ channels open -exocytosis of dopamine -dopamine receptor creates signal for meduallary centers for icnreased ventilation |
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What does exercise do to respiration?
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-20X increase in O2 use
-increased ventilation allows blood oxygen, CO2, and pH to remain normal -anterial pH--> inc. ventilation -CNS co-transmission to skeletal muscle/respiratory muscle -joint proprioreceptir feedback |
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What does high altitude acclimatization do to respiration?
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-loss of sensitivity to CO2 by respitory center neurons--> greater oxygen mediated respiratory drive
-erythropoietin stimulated Hb, rbc production -DPG-mediated right shift in Hb dissociation curve -angiogenesis occurs-->increased capillaries -stimulates peripheral chemoreceptors |
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What can voluntary control, irritant receptors, and respiratpory center depression control in respiration?
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-periodic breathing
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What is periodic breathing?
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-chenye-storkes breathing
-increased delaytime in flow of blood from lungs to brain -abnormal feedback of the respiratory center mechanisms for control of repsiration |
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What is sleep agnea?
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-absense of spontanous breathing up to 10 sec/expisode
-200+ epsiodes./night -due to pahrynx/upper airway obstruction, impaired respiratory drive |
