BIOL 460 1st Edition Lecture 13 Outline of Last Lecture I Smooth Muscle a Multiunit b Single unit c Excitation contraction coupling II The Heart Circulatory System Chapter 9 Outline of Current Lecture I Valves a AV valves b Semilunar valves II Path of Blood in Heart III Cardiac Cycle Current Lecture 1 Valves prevent backflow a AV valves i R tricuspid ii L bicuspid iii Flaps are connective tissue iv Underside connected to connective tissue fibers chordae tenineae other end connects to papillary muscles in ventricle v This holds the valve in place so they don t open the other way during contraction vi Murmurs 1 Backflow due to damaged valve 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 2 Caused by streptococcus pyrogenase antibodies for strep attach to connective tissues in body causing destruction of those cells 3 Don t class all the way incompetent b Semilunar Valves i 3 cusps ii aortic SL valve iii pulmonary SL valve iv cusps have elevated ridge v pressure of contraction pushes cusps upward DOUBLE CIRCUIT HEART 1 R SIDE PULMONARY CIRCUIT 2 L SIDE SYSTEMIC CIRCUIT 3 Know path of blood a superior a and inferior b vena cava main veins that receive blood from the body b Right atrium receives blood from the body via the vena cavae i Atria are on the top in the heart c The blood then passes through the right atrioventricular valve which is forced shut when the ventricles contract preventing blood from reentering the atrium d The blood goes into the right ventricle note that it has a thinner wall it only pumps to lungs i Ventricles are on the bottom of the heart e The right semilunar valve marks the beginning of the artery f The pulmonary artery is the main artery taking deoxygenated blood to the lungs g Blood goes to the right and left lungs where capillaries are in close contact with the thin walled alveoli so the blood can release CO2 and pick up O2 h From the lungs the pulmonary vein carries oxygenated blood back into the heart i The left atrium receives oxygenated blood from the lungs j The blood passes through the left atrioventricular valve AV valve k The blood enters the left ventricle l The blood passes through the left semilunar valve at the beginning of the aorta i aorta is the main artery to the body 1 coronary artery supplies blood to the heart muscle itself so it can pump 2 A blockage of the coronary artery or one of its branches is very serious because this can cause portions of the heart to die if they don t get nutrients and oxygen a coronary heart attack m n o p q r 3 From the capillaries in the heart muscle the blood flows back through the coronary vein which lies on top of the artery The aorta divides into arteries to distribute blood to the body Small arteries are called arterioles The smallest vessels are the capillaries These join again to form venules the smallest of the veins These in turn join to form the larger veins which carry the blood back to the superior and inferior vena cava The atrioventricular and semilunar valves prevent backflow as the heart contracts i Defects in any of these that allow some blood to leak backwards because distinctive sounds through a stethoscope thus are called heart murmurs Cardiac Cycle 1 2 3 4 5 6 7 See chart in notes Systole contraction Diastole relaxation Both atrial and ventricular systoles and diastoles nitially whole heart is in diastole Pressure fills heart with blood ventricles are 80 full Atrial systole a Blood moves to ventricles b Gives end diastolic volume EDV amount of blood in ventricles at end of ventricular diastole 115mL 8 Ventricular Systole a Ventricles eject 2 3 of blood about 70mL STROKE VOLUME b Gives end systolic volume ESV 45mL 9 Blood pressure is in mmHg 10 Time is in seconds one cycle is about 0 8s
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