The Cardiovascular System The cardiovascular system consists of the heart and blood vessels (arteries, capillaries and veins.) Supplies oxygen and nutrients to tissues, removes wastes Pulmonary circuit carries deoxygenated blood to the lungs to release CO2 and pick up O2 Systemic circuit sends oxygenated blood to cells of the body and picks up CO2 from cells.

The systemic circuit delivers oxygen to all body cells and carries away wastes. Deoxygenated blood The pulmonary circuit eliminates carbon dioxide via the lungs and oxygenates the blood. Oxygenated blood Oxygenated blood pumped to all body tissues via aorta Deoxygenated blood pumped to lungs via pulmonary arteries O2 O2 CO2 CO2 CO2 O2 CO2 O2 CO2 CO2 CO2 O2 Alveolus O2 O2 O2 CO2 Oxygenated blood returns to heart via pulmonary veins Deoxygenated blood returns to heart via venae cavae Left atrium Right atrium Left ventricle Right ventricle

The Heart Pericardium is a dense fibrous connective tissue covering the heart ( sac around the heart) 3 distinct layers underneath pericardium epicardium-contains coronary arteries and vessels that nourish the heart myocardium- contains heart muscle tissue endocardium-contains Purkinge fibers that innervate the heart

Pericardial cavity Parietal pericardium Fibrous pericardium Endocardium Coronary blood vessel Myocardium Epicardium (visceral pericardium)

Chambers of the Heart 4 chambers 2 thin walled atria that receive blood from the body Right atrium receives deoxygenated blood from the body Left atrium receives oxygenated blood from the lungs 2 thick walled ventricles that pump blood to the body Right ventricle pumps deoxygenated blood to the lungs Left ventricle pumps oxygenated blood to the body

Systemic capillaries Tissue cells CO2 Superior vena cava O2 Pulmonary artery Alveolus CO2 CO2 Alveolar capillaries Alveolar capillaries O2 O2 Alveolus Pulmonary veins Right atrium Left atrium Tricuspid valve Mitral valve Pulmonary valve Left ventricle Right ventricle Aortic valve Inferior vena cava Aorta O2 CO2 Systemic capillaries Tissue cells

Right lung Left lung Superior vena cava Aorta Pulmonary trunk Diaphragm Left auricle Right auricle Cut edge of fibrous pericardium Right atrium Cut edge of parietal pericardium Heart (covered by visceral pericardium) Right ventricle Left ventricle Pericardial cavity

Valves Pulmonary Valve -prevents backflow of blood into the right ventricle as blood is pumped to lungs Aortic valve -prevents backflow of blood into the left ventricle Right Atrioventricular valve (AV) (tricuspid)-prevents backflow of blood into the right atrium from the ventricle Left Atrioventricular valve (bicuspid or mitral valve)-prevents backflow of blood into the left atrium from the ventricle VisibleBody

Anterior View of Heart Aorta Superior vena cava Left pulmonary artery Right pulmonary artery Pulmonary trunk Left pulmonary veins Right pulmonary veins Left auricle Left coronary artery Right auricle Great cardiac vein Anterior interventricular artery (left anterior descending artery) Right coronary artery Anterior cardiac vein Left ventricle Small cardiac vein Inferior vena cava Right ventricle Apex of the heart (a)

Posterior View of Heart Fig13.09b Posterior View of Heart Superior vena cava Aorta Right pulmonary artery Left pulmonary artery Left pulmonary veins Right pulmonary veins Left auricle Circumflex artery Left atrium Cardiac vein Right atrium Inferior vena cava Coronary sinus Middle cardiac vein Left ventricle Posterior interventricular artery Right ventricle (b) Apex of the heart

Systole/Diastole

The Cardiac Cycle Atrial Systole- contracting atria, relaxing ventricles. Ventricular systole –contracting ventricles, relaxing atria Diastole- when the entire heart is relaxing

Valves and Contractions of the Heart Pulmonary valve closed Aortic valve closed Pulmonary valve open Aortic valve open RA LA Atrial systole Atrial diastole Ventricular systole Tricuspid and mitral valves open LV Tricuspid and mitral valves closed Ventricular diastole RV (a) (b)

Heart Sounds Due to vibrations in heart tissues as blood rapidly changes velocity within the heart. Heart sounds can be described as a "lubb-dupp" sound. First sound (lubb) -ventricles contract and A-V valves are closing Second sound (dupp)-ventricles relax and aortic and pulmonary valves are closing.

Electrocardiogram An electrocardiogram (ECG) is a recording of the electrical changes that occur during a cardiac cycle.

Electorcardiogram (a) 1.0 R .5 T P Millivolts Q –.5 S 200 400 600 (b) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. (a) 1.0 R .5 T P Millivolts Q –.5 S 200 400 600 (b) Milliseconds

Blood Pressure Blood pressure -force of blood against inner walls of blood vessels anywhere in the cardiovascular system. As blood gets further and further from the left ventricle, blood pressure decreases. Pulse-The surge of blood that occurs with ventricular contraction and can be felt at certain points in the body. Caused by the expansion and contraction of blood vessels Systolic pressure- During ventricular contraction, arterial pressure is at its highest. Diastolic pressure- When ventricles are relaxing, arterial pressure is at its lowest.

Normal blood Pressure= 120/80 or less

Taking Blood Pressure Subject is seated and relaxed. Wrap the fabric cuff around the upper arm Locate the brachial artery Place the diaphragm of the stethoscope over the brachial artery so that you can hear Kortokoff sounds

Taking Blood Pressure Close the valve and pump air until the pressure reads 180mmHg. Open the valve of the bulb slowly until the pressure in the cuff drops at a rate of about 2 or 3 mm Hg per second. Listen for the sounds from the brachial artery-1st loud tapping sound=systolic pressure. When sounds suddenly are muffled= diastolic pressure.