Anatomy of the Heart: Anatomy of the Heart 2008 by Rory Prue Galveston College Paramedic Class
Objectives: 2 Objectives Describe the anatomy of the heart Identify major structures of the vascular system Define preload and afterload Identify the arterial blood supply to heart Compare & contrast coronary arterial distribution Define functional properties of cardiac muscle Describe the clinical significance of Starling’s law
Topics: 3 Topics Location of the Heart Anatomy of the Heart Tissue Layers of the Heart Valves of the Heart Blood Flow through the Heart Coronary Circulation Peripheral Circulation
Location of Heart: 4 Location of Heart In mediastinum of thoracic cavity 2/3 of heart's mass lies left of midline of sternum
Location of Heart: 5 Location of Heart
Heart Anatomy: 6 Heart Anatomy
Tissue Layers of the Heart: 7 Tissue Layers of the Heart Tissue Layers Endocardium Myocardium Pericardium Visceral pericardium Parietal pericardium Pericardial fluid
Slide 8: 8
Valves of the Heart: 9 Valves of the Heart Valves Atrioventricular Valves Tricuspid valve Mitral valve Semilunar Valves Aortic valve Pulmonic valve Chordae Tendonae
Semilunar Valves: 10 Semilunar Valves
Blood Flow Through Heart: 11 Blood Flow Through Heart Blood Flow From the Body Right atrium To the Lungs Right ventricle From the Lungs Left atrium To the Body Left ventricle
Normal Blood Flow: 12 Normal Blood Flow
Coronary Circulation: 13 Coronary Circulation Coronary Circulation Collateral Circulation
Coronary Vessels: 14 Coronary Vessels
Coronary Arteries: 15 Coronary Arteries Supply arterial blood to heart muscle Left coronary artery carries about 85% of blood supply to myocardium Right coronary artery carries remainder Originate above aortic valve
Coronary Arteries: 16 Coronary Arteries
Left Coronary Artery: 17 Left Coronary Artery Divides into left anterior descending and circumflex arteries Left anterior descending (LAD) supplies: Anterior wall of left ventricle Interventricular septum Circumflex supplies: Lateral and posterior portions of left ventricle Part of right ventricle
Coronary Capillaries: 18 Coronary Capillaries Exchange nutrients and metabolic wastes Merge to form coronary veins Coronary sinus empties into right atrium Major vein draining myocardium
Arteries and Veins: 19 Arteries and Veins Three layers in all blood vessel walls (except capillaries and venules) Tunica intima Inner layer Tunica media Middle layer Tunica adventitia Outer layer
Blood Vessels: 20 Blood Vessels
Peripheral Circulation (continued): 21 Peripheral Circulation (continued) Flow of blood Ventricles Arteries Arterioles Capillaries Venous system
Arterial System: 22 Arterial System Conducting arteries Large Distributing arteries Small to medium Arterioles Smallest
Capillary Network: 23 Capillary Network Blood supplied to capillary network by arterioles Blood flows through network into venules Regulated precapillary sphincters Exchange nutrients and wastes
Venules: 24 Venules Similar to capillaries Collect blood from capillaries and transport to small veins Nutrient exchange across walls of venules
Venous System: 25 Venous System Walls are layer of smooth muscle cells Medium-sized and large veins Carry blood to venous trunks and then the heart Large veins Valves allow blood flow to but not from the heart Prevents backflow of blood
Poiseuille’s Law: 26 Poiseuille’s Law Larger diameter – Greater the blood flow “flow through a vessel directly proportional to the fourth power of the vessel’s radius” Example radius of 1 would transport 1 mL/min. of blood at pressure difference of 100 mmHg Increase radius to 4, the flow would increase to 256 (4 4 ) mL/min at same pressure
Anastomoses: 27 Anastomoses Allows blood flow from arteries to veins Without passing through capillaries Natural AV shunts Sole of foot and nail beds Regulate body temperature Pathological shunts Injury or tumors
Cardiac Cycle: 28 Cardiac Cycle Systole Atrial Ventricular Diastole Atrial Ventricular
Diastole: 29 Diastole
Systole: 30 Systole
Cardiac Output: 31 Cardiac Output Stroke volume Heart rate Contractility Starling's law
Starling’s Law: 32 Starling’s Law The greater the heart is stretched the greater the force of contraction to a certain point.
Summary: 33 Summary Location of the Heart Anatomy of the Heart Tissue Layers of the Heart Valves of the Heart Blood Flow through the Heart Coronary Circulation Peripheral Circulation Starling’s Law