L1 - Heart & Cardiovascular System Flashcards
what is the heart?
the largest organ of the mediastinum of thorax
what is the apex beat?
point of maximal impulse of heart
5th left intercostal, midclavicular line
what are the 2 layers of cardiac pericardium?
- Fibrous Pericardium - fibrous tissue (CT) adherent to central tendon of diaphragm
- Serous Pericardium - 2 layers - parietal and visceral (epicardium) pericardium
what is pericarditis?
inflammation of pericardium
what is pericardial effusion?
excess fluid in pericardial cavity - constricts cardiac movement
what are the two circulations and where do they go?
pulmonary: RV -> pulmonary arteries -> lungs -> pulmonary veins -> LA
systemic: LV -> aorta -> body -> vena cava -> RA
what is the function of the heart valves?
prevent backflow
what are the types of valves?
atrioventricular valves: between atria and ventricles
right = tricuspid
left = bicuspid
semilunar valves: at junction of ventricles & great arteries
describe three features of the atria?
- irregularly shaped
- auricle = tapering shape
- interatrial septum
what is the fossa ovalis?
depression in the interatrial septum of right atria
remains of foramen ovale in embryo
give two features of the right ventricle’s interventricular septum? (upper and lower)
muscular/thick major part and membranous (thin upper part)
give three features of the internal wall of the ventricles?
- trabeculae carneae (muscular ridges)
- papillary muscles
- chordae tendineae (connects tricuspid valves to papillary muscles)
name three features of the left ventricle?
- apex
- mitral valve
- semilunar valves
in the atrioventricular valves, what are the chordae tendineae attached to?
- free margin & ventricular surface of leaflet
- papillary muscles (project into ventricles)
what is ventricular diastole?
valve relaxed and open
what is ventricular systole?
papillary muscles contract - pulling cusps together - chordae tendineae prevent cusps being blown backward into atrium - valve closed
what are the two semilunar valves?
pulmonary and aortic
what is valve stenosis?
valve doesn’t open properly, narrow opening, reduced blood flow
what is valve incompetence/leak?
valve does not close properly = backflow
normal amount of blood pumped at one time 55%
leaking valve = 25%
where do coronary arteries arise from?
aorta sinuses located in coronary sulcus
what is ischemic heart disease?
inadequate oxygenation of myocardium
what drains the right atrium?
coronary sinus - main vein in coronary sulcus tributaries
what are the layers of the heart wall?
- epicardium (visceral pericardium)
- myocardium (cardiac muscle)
- endocardium (inner lining)
what is the sino-atrial node?
- pacemaker
- wall of RA at junction of superior vena cava
