BCMB 230 1st Edition Lecture 18 Outline of Last Lecture I Pressure II Coagulation and Hemostasis III Clotting Outline of Current Lecture I Anticlotting II Review of Vasoconstriction and Vasodilation III Respiratory System IV Lungs Current Lecture I Anticlotting Three organs particularly susceptible to blockage from free floating clots heart brain stroke and kidney break loose and have the ability to block arteries we need to keep clots from forming at inappropriate times Anticlotting prevention of clots tissue factor inhibitor produced by endothelial cells blocks extrinsic pathway thrombomodulin protein that acts as a receptor on endothelial cells for thrombin when produced in blood thrombin bonds to thrombomodulin this complex activates an additional plasma membrane called protein c when protein c is activated by binding to the complex it has a negative feedback effect on factor VIII and factor V the same factors that thrombin has a positive feedback effect on which reduces clotting antithrombin inactivates thrombin and other factors removing them from the blood works better if heparin is present in endothelial cells heparin can be administered as a drug fibrinolytic system fibrinolytic clot removal process that is important for clot removal plasminogen activator produced by endothelial cells turns into the active form called plasmin plasmin takes fibrin and breaks it into smaller fragments that are soluble again Actions of thrombin These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute procoagulant cleaves fibrinogen to fibrin activates clotting factors XI VIII V and XIII stimulates platelet activation anticoagulant activates protein C which inactivates clotting factors VIII and V Anticlotting Roles of Endothelial Cells provide physical barrier between blood and connective tissue release PGI and nitric oxide which inhibits platelet activation and aggregation secrete tissue factor pathways inhibitor which inhibits ability of tissure factor bind thrombin via thrombomodulin which then activates protein C inactivating clotting factors VIII and V display heparin molecules on the surfaces of their plasma membranes heparin binds antithrombin III and this molecule then inactivates thrombin and several other clotting factors secrete tissue plasminogen activator tissue plasminogen activator catalyzes the formation of plasmin which dissolves clots Aspirin a low dose can prevent clotting acts on cyclooxenase enzyme prevents production of prostaglandins and thromboxanes prostaglandins produced by endothelial cells inhibit platelet activation thromboxanes produced by platelets promote platelet activation endothelial cells can make more enzymes prostaglandin can still be produced platelets cannot make more enzyme thromboxane cannot still be prodcued II Review of Vasoconstriction and Vasodilation Vasoconstriction and vasodilation happen in both arteries and veins Arteries maintain pressure while veins have a much broader range of pressure low pressure system in both vasoconstriction leads to increased resistance increase in resistance decreases flow pressure constant increase pressure and resistance increase flow pressure changed Vasodilators nitric oxide constriction in artery one form of heart attack cardiac pain treated by giving patient a nitroglycerin tablet and put under tongue breaks down into nitric oxide increases blood flow to heart by vasodilating those arteries erectile dysfunction can take drugs to enhance vasodilation of penal blood supply to get erection getting too much vasodilation leads to drop in blood pressure drugs not specific for where we want to go goes to other places too if vasodilating drugs are taken together blood pressure can drop dangerously III Respiratory System Different pathway to deal with two way street Nostril nasal cavity pharynx larynx trachea bronchi bronchioles go down reverse flow and go back out Bronchi and bronchioles are in the lungs Respiratory system has different functions gas exchange bring oxygen in to bodies remove carbon dioxide clot filter lungs not dependent on blood supply for oxygen so lungs can handle small clots very easily lungs help remove these clots before they can get out to other tissues big clot in the lungs can kill you speech function of larynx within larynx there are vocal ligaments connective tissue two on either side of larynx have mucus membrane over them so that vocal ligaments form what we call vocal cords which vibrate and produce the basic sounds of speech lips tongue mouth change it into words recognizable sounds damage to larynx can lose ability to speak make sound vocal cords and larynx have a protective function pharynx shares with digestive system want to make sure food and water don t go into lungs goes into esophagus which is right behind the larynx two doors to shut off larynx epiglottis and glottis close glottis and exhale produce a lot of pressure and thoracic and abdomible cavities happens when you defecate or urinate val salva maneuver use this for defecation urination and spinal support increase thoracic cavity pressure which can put a strain on heart IV Lungs Use same formula F P R cartilage lining tract allows for lower resistance Pressure greater outside then inside of body air moves inside increase pressure in thoracic cavity air goes out Boyles Law pressure volume gas law increase volume of container decrease pressure inhale decrease volume of container increase pressure exhale main muscle to control this voluntarily diaphragm goes all the way across the body cavity forms barrier between thoracic cavity and abdominable cavity relaxed in a domed up position contracted in a lower position dropping diaphragm gets inhale relax diaphragm gets exhale tidal volume amount of air moved from diaphragm volumes depends on body size forced inhalation take a deep breath get a lot of air into lungs pull ribs up increase volume forced exhalation pull ribs down to decrease volume use intercostal muscles and muscles in abdominal wall