11 PART A The Cardiovascular System PowerPoint® Lecture Slide Presentation by Jerry L Cook, Sam Houston University ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY EIGHTH EDITION ELAINE N MARIEB Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings The Heart Figure 11.1 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings The Heart: Coverings Pericardium – a double serous membrane Visceral pericardium Next to heart Parietal pericardium Outside layer Serous fluid fills the space between the layers of pericardium Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Blood Circulation Figure 11.3 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings The Heart: Chambers Right and left side act as separate pumps Four chambers Atria Receiving chambers Right atrium Left atrium Ventricles Discharging chambers Right ventricle Left ventricle Figure 11.2c Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings The Heart: Valves Valves open as blood is pumped through Held in place by chordae tendineae (“heart strings”) Close to prevent backflow Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Operation of Heart Valves Figure 11.4 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Coronary Circulation Blood in the heart chambers does not nourish the myocardium The heart has its own nourishing circulatory system Coronary arteries Cardiac veins Blood empties into the right atrium via the coronary sinus Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings External Heart Anatomy Figure 11.2a Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Major Veins of Systemic Circulation Figure 11.12 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Arterial Supply of the Brain Figure 11.13 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Hepatic Portal Circulation Figure 11.14 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Circulation to the Fetus Figure 11.15 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Pulse Pulse – pressure wave of blood Monitored at “pressure points” where pulse is easily palpated Figure 11.16 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Blood Pressure Measurements by health professionals are made on the pressure in large arteries Systolic – pressure at the peak of ventricular contraction Diastolic – pressure when ventricles relax Pressure in blood vessels decreases as the distance away from the heart increases Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Measuring Arterial Blood Pressure Figure 11.18 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Blood Pressure: Effects of Factors Neural factors Autonomic nervous system adjustments (sympathetic division) Renal factors Regulation by altering blood volume Renin – hormonal control Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Blood Pressure: Effects of Factors Temperature Heat has a vasodilation effect Cold has a vasoconstricting effect Chemicals Various substances can cause increases or decreases Diet Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Factors Determining Blood Pressure Figure 11.19 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Variations in Blood Pressure Human normal range is variable Normal 140–110 mm Hg systolic 80–75 mm Hg diastolic Hypotension Low systolic (below 110 mm Hg) Often associated with illness Hypertension High systolic (above 140 mm Hg) Can be dangerous if it is chronic Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Shock and Homeostasis Shock is an inadequate cardiac output that results in failure of the cardiovascular system to deliver enough oxygen and nutrients to meet the metabolic needs of body cells Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Signs and Symptoms of Shock Cool, clammy, pale skin due to vasoconstriction of skin blood vessels Tachycardia due to sympathetic stimulation and increased levels of epinephrine Weak, rapid pulse due to generalized vasodilation and reduced cardiac output Sweating due to sympathetic stimulation Hypotension in which the systolic blood pressure is lower than 90mmHg as a result of generalized vasodilation and decreased cardiac output Altered mental state due to cerebral hypoxia Reduce urine formation due to hypotension and increased levels of aldosterone and antidiruretic hormone (ADH) Thirst due to loss of extra cellular fluid Acidosis due to buildup of lactic acid Nausea due to impaired circulation to the digestive system Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Aging and the Cardiovascular System General changes include loss of elasticity of blood vessels, reduction in cardiac muscle size, reduced cardiac output and increased systolic blood pressure The incidence of coronary artery disease, congestive heart failure and atherosclerosis increased with age Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Developmental Aspects of the Cardiovascular System A simple “tube heart” develops in the embryo and pumps by the fourth week The heart becomes a four-chambered organ by the end of seven weeks Few structural changes occur after the seventh week Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings