Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Remote ischemic conditioning wikipedia , lookup
Management of acute coronary syndrome wikipedia , lookup
Cardiac contractility modulation wikipedia , lookup
Heart failure wikipedia , lookup
Coronary artery disease wikipedia , lookup
Quantium Medical Cardiac Output wikipedia , lookup
Jatene procedure wikipedia , lookup
Lutembacher's syndrome wikipedia , lookup
Congenital heart defect wikipedia , lookup
Electrocardiography wikipedia , lookup
Heart arrhythmia wikipedia , lookup
Dextro-Transposition of the great arteries wikipedia , lookup
The Cardiovascular System Chapter 11 Heart is two pumps in one: Right side – pulmonary circulation Left side – systemic circulation Heart→ Arteries → Arterioles → Capillaries → Venules→ Veins → Heart Artery – any vessel that carries blood AWAY from the heart. Vein – any vessel that carries blood TOWARD the heart Parietal pericardium: outer fibrous layer inner serous layer Pericardial cavity Visceral pericardium Pericarditis Heart Wall Layers (superficial to deep): 1. Epicardium – serous membrane 2. Myocardium – muscle layer 3. Endocardium – continuous throughout circulatory system Cardiac Muscle: involuntary, striated Intercalated discs: gap junctions functional syncytium desmosomes – “spot welds” Ventricular Geometry LV RV Common Disorders Ischemia – reduced blood flow Hypoxia – reduced oxygen supply Angina pectoris – “strangled chest” referred pain Myocardial infarction – death of an area of tissue due to interrupted blood flow (“Heart attack”) Congestive heart failure – heart is unable to supply bloodflow to body Fibrillation – uncoordinated, unsynchronized beating of heart, no net bloodflow Cardiac cycle One complete heart beat: •Systole (contraction) and •Diastole (relaxation) of both ventricles •Remember: Blood pressure = systole/diastole ≈ 120/80 normal average “Heart beat” • http://www.youtube.com/watch?v=ZlB915CfCg • http://www.youtube.com/watch?v=7eFn8Cgc x8g • http://www.youtube.com/watch?v=NYBrJZQt4w&feature=fvw Know sequence of cardiac cycle Know sequence of cardiac cycle - Know http://www.youtube.com/watch?v=12_nJamoyTk understan d Cardiac Muscle Contraction http://www.youtube.com/watch?v=IjU81a5TjZs; know http://www.dnatube.com/video/317/Beating-Heart-Cell; • http://www.youtube.com/watch?v=55tAIOcBg3w&feature=related; Heart muscle: – Is stimulated by nerves and is self-excitable (automaticity) – Contracts as a unit – Has a long (250 ms) absolute refractory period http://www.youtube.com/watch?v=_gbGA5il4Sg • Cardiac muscle contraction is similar to skeletal muscle contraction Heart Physiology: Intrinsic Conduction System - know • Autorhythmic cells: – Initiate action potentials – Have unstable resting potentials called pacemaker potentials – Use calcium influx (rather than sodium) for rising phase of the action potential http://www.youtube.com/watch?v=Lhl897Mz-h8&feature=related; http://www.interactivephysiology.com/demo/systems/buildframes.html?cardio/ actnpot/01 Pacemaker and Action Potentials of the Heart - know Heart Physiology: Sequence of Excitation - know • Sinoatrial (SA) node generates impulses about 75 times/minute • Atrioventricular (AV) node delays the impulse approximately 0.1 second • Impulse passes from atria to ventricles via the atrioventricular bundle (bundle of His) http://www.smm.org/heart/heart/pumping.htm; http://depts.washington.edu/physdx/heart/demo.html Heart Physiology: Sequence of Excitation - know • AV bundle splits into two pathways in the interventricular septum (bundle branches) – Bundle branches carry the impulse toward the apex of the heart – Purkinje fibers carry the impulse to the heart apex and ventricular walls Heart Physiology: Sequence of Excitation - know Heart Excitation Related to ECG know Extrinsic Innervation of the Heart know • Heart is stimulated by the sympathetic cardioaccelerator y center • Heart is inhibited by the parasympathetic cardioinhibitory center Electrocardiography - know • Electrical activity is recorded by electrocardiogram (ECG) • P wave corresponds to depolarization of SA node • QRS complex corresponds to ventricular depolarization • T wave corresponds to ventricular repolarization • Atrial repolarization record is masked by the http://www.youtube.com/watch?v=lYMSkGXFoN4&feature=related larger QRS complex Electrocardiography (EKG) http://www.y outube.com/ watch?v=ew 6Jp74vaN4 Heart Murmurs – abnormal sounds caused by the flow of blood. Mitral stenosis (abnormal narrowing) Mitral valve prolapse (turns “inside out”) 1. 2. 3. Conduction system of the heart Sinoatrial (SA) node – “pacemaker’ → Atrioventricular (AV) node → Atrioventricular (AV) Bundle - Bundle of His→ Purkinje fibers – conduction myofibers Ectopic pacemaker = implanted device that uses electrical impulses to reproduce or regulate the rhythms of the heart Ectopic pacemaker ECG (or EKG) • An electrocardiogram (ECG / EKG) is an electrical recording of the heart and is used in the investigation of heart disease. • Normal adult 12-lead ECG: Abnormally slow heartbeat Abnormally fast heartbeat Regulation of Heart Rate • Sympathetic N.S. increases heart rate and force of contraction through increased epinephrine secretion • Parasympathetic N.S. decreases heart rate and force of contraction through the vagus nerve. Sends continuous impulses. Secretes acetylcholine Other factors that influence heart rate • • • • Temperature Ion concentration K+ and Ca + + Hormones Hypoxia, acidosis and alkalosis slow heart • Age • Gender • Physical fitness Fetal Circulation • Obtains oxygen and nutrients from maternal circulation • Two arteries off internal iliac arteries run through umbilical cord • Umbilical vein returns oxygenated blood • Several shunts in fetal circulation: •Ductus venosus – bypasses fetal liver and dumps blood from umbilical vein into inferior vena cava. •Foramen ovale – hole in atrial septum, blood passes from right atrium to left atrium, bypassing the developing lungs •Ductus arteriosus – connects pulmonary artery with aorta •If does not close – patent ductus arteriosus – get mixing of venous and arterial blood.