corazon Flashcards
configuracion interna configuracion externa irrigacion sistema de conduccion
where is the heart located
in the middle mediastinum
what surrounds the heart
the pericardium / epicardium
- the fibrous pericardium: tough, outer layer that reflects onto great vessels
- serous pericardium: layer that lines inner aspect of fibrous pericardium (parietal layer); reflects onto heart as epicardium (visceral layer)
features of the right atrium
- auricle: pouchlike appendage of atrium, embryonic heart tube derivative
- pectinate muscles: ridges of myocardium inside auricle
- crista terminalis: ridge that runs from the inferior to the superior vena cava openings, its superior extent masks the site of the SA node
- fossa ovalis: depression in interatrial septum’ former site of foramen ovale
- atrial openings: one of each for superior vena cava, inferior vena cava and coronary sinus (venous return from cardiac veins)
features of the right ventricle
- tuberculae carneae: irregular ridges of ventricular myocardium
- papillary muscles: anterior, posterior and septal projections of myocardium extending into ventricular cavity; prevent valve leaflet prolapse
- chordae tendineae: fibrous cords that connect papillary muscles to valve leaflets
- moderator band: muscular band that conveys AV bundle from septum to base of ventricle at site of anterior papillary muscle
- ventricular openings: one to pulmonary trunk through pulmonary valve; one to receive blood from right atrium through triscuspid valve
name the valves of the right side of the heart
- tricuspid valve (RIGHT AV valve) (has two valve leaflets)
- pulmonary valve (pulmonic semilunar valve) (has three valve leaflets)
features of the left atrium
- auricle: small appendage representing primitive embryonic atrium whose wall has pectinate muscles
- atrial wall: wall slightly thicker than thin-walled right atrium
- atrial openings: usually four openings for four pulmonary veins (2 superior and 2 inferior)
features of the left ventricle
- papillary muscles: anterior and posterior muscles, larger than those of right ventricle
- chordea tendineae: fibrous cords that connect papillary muscles to valve leaflets
- ventricular wall: wall much thicker than that of right ventricle
- membranous septum: very thin superior portion of interventricular septum (IVS) and site of most ventricular septal defects
- ventricular openings: one to aorta through aortic valve; one to receive blood from left atrium through mitral valve
name the valves of the left side of the heart
- mitral valve (LEFT AV valve)
- aortic valve (aoritc semilunar valve)
Donde se escucha el foco aortico
segundo espacio intercostal linea paraesternal derecha
donde de escucha el foco pulmonar
segundo espacio intercostal linea paraesternal izquierda
donde de escucha el foco tricuspideo
cuarto espacio intercostal linea paraesternal izquierda
donde de escucha el foco mitral / apex
quinto espacio intercostal linea media clavicular izquierda
what innervates the pericardium and the heart
- the pericardium is innervated by somatic pain fibers that course in the phrenic nerves (C3 - C5)
- the heart itself is innervated by the autonomic nervous system
what are the chief components of the hear innervation
ANS:
- parasympathetics: derived from the vagus nerge (X), which courses to the cardiac plexus; parasympathetic stimulation slows the hear rate and decreases the force of contraction
- sympathetics: derived from cervical and thoracic cardiac nerves originating in the T1-T4 intermediolateral cell column,these fibers course to the cardia plexus; sympathetic stimulation increases heart rate and force of contraction
- afferents: sensory nerve fibers course from the heart in the sympathetic nerves to dorsal root ganglia associated with T1-T4 spinal cord levels; these fibers convey pain associated with myocardial ischemia.
what is the SA node
it’s the pacemaker of the heart; site where action potential is initiated, located in the right atrium