Large Arteries of Heart

Transcription

1 Cardiovascular System (Part A-2) Module 5 -Chapter 8 Overview Arteries Capillaries Veins Heart Anatomy Conduction System Blood pressure Fetal circulation Susie Turner, M.D. 1/5/13 Large Arteries of Heart Pulmonary Arteries Carry Deoxygenated Blood From Right Ventricle to Lungs Aorta Carries Oxygenated Blood From Left Ventricle to Body Thru Large Aortic Arch 1

2 Large Veins of Heart Superior vena cava Drains venous blood from upper body to right atrium Inferior vena cava Drains venous blood from lower body to right atrium Pulmonary Veins Carry oxygenated blood from lungs to left atrium Atrioventricular Valves Connect the 2 atria with the 2 ventricles Have leaf-like cusps Attached to wall by heart strings Chordae Tendinae Right Side Tricuspid Valve 3 cusps Left Side Bicuspid Valve 2 cusps Mitral valve 2

3 Semilunear Valves Connect the 2 ventricles & their outgoing arteries. Both have 3 pocket-like cusps Pulmonary (Pulmonic) Valve Between Right Ventricle & Pulmonary Artery Aortic Valve Between Left Ventricle & Aorta Atrioventricular Valves Tricuspid Bicuspid Fig. 20-6b, p

4 Semilunear Valves Pulmonic Aortic Fig. 20-8c, p. 679 Heart Contraction Diastole Relaxation of a heart chamber Fills with blood Systole Contraction of a heart chamber Ejection of blood *Ventricular Action Most Important Pumping blood to body & lungs 4

5 Coronary Arteries Supply oxygenated blood to heart muscle Like a crown sitting on top of the heart. Right coronary artery Supplies right side of heart Left coronary artery Supplies the left side of the heart. Divides into left anterior descending artery & circumflex artery Cardiac Conduction System Specialized cardiac tissue known as conductive tissue. Initiates & spreads electrical impulses to cardiac muscle 1. SA Node Sinoatrial Node Pacemaker 2. AV Node Atrioventricular node Conducts impulse to ventricular wall. 3. AV Bundle Bundle of His Conducts impulse thru septum 4. Right & Left Bundle Branches Conduct impulse to prospective ventricles 5. Purkinjie Fibers Special barrel shaped cells Branch into ventricular walls to conduct impulse to cardiac muscle cells 5

6 Electrocardiography Conduction of electrical impulses thru heart generates electrical currents. Eventually spread thru body Electrical impulses can be detected on the surface of the body Electrocardiogram Graphic recording of the electrical changes during cardiac cycle EKG or ECG Depolarization followed by Repolarization Electrocardiograph Instrument that can detect & record EKG. EKG 6

7 Summary of Electrical Heart Events *EKG only shows electrical events Does not tell you if muscle is contracting. ****ALWAYS CHECK FOR A PULSE Force exerted against arterial walls Major determinant is contraction of left ventricle Systole Contraction Phase Diastole Relaxation Phase Blood Pressure 7

8 Blood Pressure Sphygmomanometer Blood pressure cuff Instrument used to obtain blood pressure By listening with stethoscope Auscultation Ex; BP is 120/80 Systolic BP is 120 Diastolic BP is 80 Sounds of Korotkoff Tapping sounds heard when taking BP Document when sound starts & stops 1. First soft tapping sounds Record as the systolic pressure 2. Sound disappears Record as the diastolic pressure Ex; BP is 120/80 Systolic BP is 120 Diastolic BP is 80 8

9 Fetal Circulation Lungs & Digestive System Not Functional 2 Shunts (Bypasses) Digestive Shunt Bypasses Liver Called Ductus Venous Pulmonary Shunt Bypasses Lungs Called Foramen Ovale & Ductus Arteriosus FETAL CIRCULATION 1. Ductus Venosus Umbilical Vein Joins to Inferior Vena Cava 2. Foramen Ovale Opening Between R and L Atria In the interatrial Septum Allows Most Blood to Bypass Lungs 3. Ductus Arteriosus Small Vessel That Connects the Pulmonary Trunk and the Aorta *All close off at birth. 9