BIOL 320 1 st Edition Lecture 6 Outline of Last Lecture I Leukocytes A Production B Disorders II Platelets III Hemostasis A Phases B Disorders IV Human Blood Groups A Transfusion Reactions Outline of Current Lecture V Rh Factor A Homeostatic Imbalance VI Developmental Aspects VII Cardiovascular System A Heart Current Lecture Rh Factor Descriptions o Rh means no antigens are present on the surface of the erythrocyte o Rh means at least one antigen is present on the surface of the erythrocyte o There are several antigens for Rh Factor but there are eight common antigens C D and E o Rh make anti Rh antibodies o First exposure when Rh is first exposed to Rh either by transfusion or pregnancy Rh is ok because the body has not made the anti Rh antibodies o Second exposure when Rh is re exposed to Rh Rh will now have the anti Rh antibodies to attach the Rh blood causing agglutination clumping of the blood This clumping will lead to a thrombus or embolism and when blood is filtered in the kidneys could cause renal failure Homeostatic Imblance o Erythroblastosis Fetalis Hemolytic disease of the newborn o Description o Mother is Rh and baby is Rh first pregnancy will be ok Second pregnancy with Rh mother and Rh baby is a problem because the mother now is sensitized and agglutination occurs when mother and baby s blood mix The baby becomes anemic and hypoxic In severe cases brain damage and even death may result o Treatment o The baby can be treated with prebirth transfusions and exchange transfusions after birth o RhoGAM serum containing anti Rh antibodies agglutinins can prevent the Rh mother from becoming sensitized By agglutinating the Rh factor it blocks the mother s immune response and prevents her sensitization Developmental Aspects o Early fetal development blood cells produced in yolk sac liver and spleen o Late fetal development blood cells produced in blood islands mesenchyme cells where bone marrow comes from which occurs in third trimester around month 7 Fetal blood also has specific kind of hemoglobin HbF HbF has a higher affinity for oxygen consequently CO 2 as well This higher affinity ensures the developing baby will get enough oxygen Hemopoiesis formation of blood cells o In younger children most bones produce blood cells Aging Effects o Leukemia anemia clotting disorders result from heart vessel and immune conditions o Older bone Marrow Structure changes Marrow gets replaced with adipose tissue Fewer leukocytes get produced See more prevalence of immune attack Thrombus more prevalent due to worsening heart and vessel tissue damage Cardiovascular System Heart o Characteristics Orientation diagonal Mediastinum medial cavity of the thorax Midline Anatomical relationships Superior to the diaphragm Deep to the sternum o Pericardium double walled sac Fibrous pericardium fibrous connective layer Serous pericardium thin slipper two layer serous membrane Pericardium fluid lubricates to reduce friction Myocardium heart muscle Endocardium seals off muscle from blood gases can t diffuse between layers meaning muscle needs its own vascular can t steal from the blood that is being pumped through atria and ventricles Pericarditis infection or inflammation of pericardial tissue build up of fluid sheath around heart creating more pressure on heart to beat resulting in heart failure o Flow of Blood briefly Right atrium receive blood from body and fill right ventricle Tricuspid valve prevents back flow between right atrium and ventricle Right ventricle pump blood to pulmonary system to re oxygenate blood via pulmonary artery Left atrium receive blood from pulmonary system via pulmonary vein and fill left ventricle Mitral bicuspid valve prevents back flow between left atrium and ventricle Left ventricle pump blood to whole body o Important Terms Structures Fossa ovalis shallow depression that marks the spot where an opening the foramen ovale existed in the fetal heart Trabeculae carneae muscle found in the ventricles of the heart Pectinate muscles muscle found in the atria of the heart o Valves Atrioventricular AV valves located at each atrial ventricular junction prevent backflow into the atria when the ventricles are contracting Includes the tricuspid and mitral valves Chordae tendinae tiny white collagen cords heart strings which anchor the cusps to the papillary muscles protruding the from the ventricular walls Papillary muscles contract with the other ventricular musculature so that they take up the slack on the chordae tendinae as the full force of ventricular contraction hurls the blood again the AV valve flaps Semilunar SL valves guard the bases of the large arteries issuing from the ventricles aorta and pulmonary trunk and prevent backflow into the associated ventricles Function of Valves Relaxed heart gravity pulls blood from atria to ventricles AV valves are open Atria contract squeeze remaining blood into ventricles Ventricles contract o Pressure pushes AV flaps closed o Papillary muscles contract keep AV flaps shut o Blood finds another path out SL valves Relaxed heart cusps of semilunar SL valves catch blood and the weight shuts them o Heart Sounds Lub dub valves closing Lub AV valves closing dub SL valves closing Heart Murmur leakage through the valves due to congenital disorder or infection the incomplete closing of valves Valve Stenosis narrowing or stiffening of the valves due to scarring of heart valves from genetic pre disposition or calcium deposits resulting in the heart having to work harder heart wearing out replace valves with cadaver valves synthetic valves