Cardiovascular Flashcards
What are the 3 layers of the heart from inside to outside?
Endocardium, myocardium (contracting muscle), epicardium
What cushions the heart and how much?
Pericardial space with 5-20ml of fluid
What does the right atrium do?
Receives deoxygenated blood from the body through the vena cavas
What does the right ventricle do?
Receives deoxygenated blood from the right atrium and then pumps the blood to the lungs through the pulmonary artery
What does the left atrium do?
Receives oxygenated blood from the lungs by the pulmonary vein
What does the left ventricle do?
Receives oxygenated blood from the left atrium then pumps the blood into the systemic circulation via the aorta
What is the left ventricle?
The largest most muscular chamber
Where is the tricuspid valve?
Top right side of heart between right atrium and right ventricle
Where is the mitral valve?
Left side of heart between left atrium and left ventricle
What do the tricuspid and mitral valves do?
Prevent back flow of blood by opening when the ventricles relax
Where is the pulmonic valve?
Between right ventricle and pulmonary artery
Where is the aortic valve?
Between the left ventricle and aortic artery
What does the pulmonary and aortic valves do?
Prevent back flow of blood during relaxation by closing when the ventricles relax
What is the S1 heart sound?
Heard when the Atrioventricular valve closes. “Lub” heard at apex of heart
What is the S2 heart sound?
Heard when the semilunar valve closes. “Dub” heard at base of heart
What is the S3 heart sound?
Heard if ventricular wall compliance is decreased or vibrating
What can an S3 sound indicate?
Heart failure or valvular regurgitation. Normal is under 30yo
What is a S4 sound?
Heard on atrial systole if resistance to ventricular filling is present
What can a S4 heart sound indicate?
Cardiac hypertrophy to injury to ventricular wall
What is depolarization? *
Mechanical activity
What is repolarization? *
Rest
The faster the HR…
The less time the heart has to fill. Decreases cardiac output
What does the sympathetic nervous system do r/t the heart and when is it stimulated? *
Releases norepinephrine which increases the HR, conduction speed through AV nodes, atrial/ventricular contractility and peripheral vasoconstriction. Stimulated when decreased pressure is detected
What does the parasympathetic nervous system do r/t the heart and when is it stimulated? *
Releases acetylcholine which decreases HR, atrial/ventricular contractility, and conductivity. Stimulated when increased pressure is detected