Heart Structure Flashcards
Pericardium
Fibrous and serous
Innervated by phrenic nerve
Blood from pericardiophrenic artery
Visceral Serous Pericardium
On heart itself
Parietal Serous Pericardium
Inner surface of pericardial sac
Cardiac Tamponade
Compression of heart due to rapid accumulation of fluid in sac
Limits ability to pump
Pericarditis
Remains substernal and does not radiate
Pain is worse lying down
Tricuspid valve
Closes at beginning of systole
Mitral valve
Closes at beginning of systole
Mitral valve prolapse
Valve everts into left atrium, due to high pressure in left ventricle
Pulmonary valve
End of systole
Aortic valve
Right and left coronary arteries open into space above valve
When is blood flow greatest?
Diastole
Blocked arteries
40-50% in left anterior descending
30-40% at base of right coronary
15-20% at left circumflex branch
Coronary circulation blood
Returns to right atrium though coronary sinus or small anterior cardiac veins
Coronary sinus
Receives all cardiac veins expect anterior cardiac and smallest cardiac veins
SA Node
Lies in right atrial wall at superior end of sulcus terminalis near superior vena cava
SA Node Conduction
Inherent rhythmicity but rate of conduction increases when stimulated by sympathetic cardiac nerves and decreases when stimulated by parasympathetic cardiac nerves
Parasympathetic Innervation
Vagus
Sympathetic Innervation
Cell bodies in sympathetic chain ganglia from C4-T5
Ischemic Cardiac Pain
Result of inadequate blood flow
Carried back with afferents that run with sympathetic nerves
Cardiac Referred Pain
Afferent innervation returns with sympathetic nerves accounts for pain to heart, upper thoracic wall and medial side of left UE
Can be referred to neck or right UE
