Heart And Mediastinum Flashcards
What part of the mediastinum is the heart and pericardium located in?
The middle mediastinum
What are the boundaries of the middle mediastinum?
Anterior: anterior mediastinum
Posterior: posterior mediastinum
Superior: angle of Louis
Inferior: diaphragm
What is the location of the heart?
Behind the sternum
Between the 2nd and 6th ribs
Between t5-t8
Apex- base of heart located at 5th intercostal space in the left midclavicular line
What are the ausculatory sites for the aortic valve, pulmonary valve, tricuspid valve, mitral valve?
Aortic valve- right second intercostal space
Pulmonary valve- left second intercostal space
Tricuspid valve- left fourth and fifth intercostal space
Mitral valve- apex beat
What is the pericardium?
Loose fitting sac surrounding the heart and roots of great vessels
What are the layers of the pericardium?
Fibrous pericardium- tough, loose-fitting inelastic - outer layer
Serous pericardium- thin- two layers
Parietal layer- lines inside of fibrous pericardium
Visceral layer: adheres to outside of heart
What is between the parietal layer and viscerally layer of the pericardium?
Pericardial space filled with pericardial fluid - decrease friction
What are pericardiophrenic vessels?
Located within and supply the fibrous pericardium
What is the function of the heart valves?
Permit blood flow in one direction during circulation
Prevents back flow of blood
What are the semi-lunar valves?
Pulmonary valves, aorta valves
What is the location of the pulmonary valve? How many cusps?
Between right ventricle and pulmonary trunk- Three semi-lunar cusps
Where is the aortic valves located? How many cusps?
Between the left ventricle and aortic- three semi-lunar cusps
What are the atrioventricular valves?
Tricuspid valves
Mitral valve
What is the location of the tricuspid valve? How many cusps? What are they connected to via what?
Between right atrium and right ventricle
3 cusps
Connected to ventricular papillary muscle via chordate tendinae
What is the location of the mitral valve? How many cusps?
Between the left atrium and left ventricle- two cusps
What is cardomegaly? How can it be identified?
The enlargement of the heart. If the shadow is over 1/2 of the thoracic shadow.
What chambers lies behind the sternu,?
The right ventricle
What does blood enter the right atrium through?
The vena cava and coronary sinus
What is the right auricle?
Right auricle - projects forward - broad triaangular muscular pouc- visible on the exterior of the heart and overlap the ascending aorta.
What is the fossa ovalis?
ossa ovalis- remanent of foramen ovale- allows oxygenated blood to pass from the right atrium to the left atrium so can bypass the lungs which are non functional before birth
Coronary sinus- veins from heart join up and go into right atrium
What is the Crista terminalis?
Crista terminalsis- a smooth, muscular ridge that begins on the roof of the atrium just in front of the opening of the superior vena cava and extends down the lateral wall to the anterior lip of the inferior vena cava
What are the pectinate muscles?
fan out from Crista- these ridges are also found in the right auricle, which is an ear like conical muscular pouch that externally overlaps the ascending aorta
Where is the SAN and what does it do?
Jus inferior to vena cava - pacemakers carry electrical impulses
Where is the AVN and and what does it do?
Boundary of tricuspid valve- delay electrical signal from SA until atrium is empty of blood
What are chordae tendinae?
Arise from papillary muscles- project from wall of ventricle
What are the papillary muscles?
Attach to tricuspid and mitral valve leaflets via the chordate tendinae and control valves
What separates the two ventricles?
Interventricular septum
What does the left aortic sinus give rise to?
Left coronary artery
What does the right aortic sinus give rise to?
Right coronary artery
What does the posterior aortic sinus give rise to?
Nothing, known as non-coronary sinus
What does the RCA branch into?
- Marginal branch
- Sinoatrial branch
- Posterior descending branch
What does the LCA branch into?
- Circumflex branch> marginal branch
- Left anterior descending artery (LAD) > diagonal branch
What is coronary artery dominance?
Defined by the vessel which gives rise to the posterior descending artery
What happens is there is a blockage near the SAN node artery?
Irregular heart Beat
What vein accompanies the marginal branch?
Small cardiac vein
What vein accompanies the posterior descending branch?
Middle cardiac vein
What vein accompanies the left anterior descending artery?
Great cardiac vein
What is the coronary sinus?
All cardiac veins drain into coronary sinus which opens into right atrium
What is the moderator band?
a muscle column the acourses inferior from the right portion of the interventricular septum to the base of the anterior papillary muscle of the right ventricle
What is the infundibulum?
conical pouch formed the upper andd left angle of the right ventricle in the chordate heater, which the pulmonary trun arises.
The outflow tract of the right ventricle, which lead to the pulmonary trunk- area has smooth walls and derives from embryonic bulbous cord is/
What happens to cardiac output when there is an increased level of fluid in the pericardial sac
decreases, because chambers of the heart are more compressed so less space for ventricles to contract and limited amount of oxygenated blood around the body
