The Heart Flashcards
Left atrium pressure
8-10mm Hg
Left Ventricle pressure
120 systole/10 diastole mm Hg
Aorta pressure
120 systole/80 diastole mm Hg
Right Atrium pressure
0-4mm Hg
Right Ventricle pressure
25 systole/4 diastole mm Hg
Pulmonary Artery pressure
25 systole/10 diastole mm Hg
Stroke Volume at rest
70ml
How long does an average action potential in the heart last for?
280ms
Valves in each side of the heart
Left - aortic valve, mitral valve
Right - tricuspid valve, pulmonary valve
What are the cusps of the mitral and tricuspid valves attached to?
Papillary muscles via cordae tendineae
How long is the electrical impulse delayed for at the atrioventricular node?
120ms
What are the 7 phases of the cardiac cycle? And what happens in each one?
1) Atrial Contraction
2) Isovolumetric Contraction
3) Rapid Ejection
4) Reduced Ejection
5) Isovolumetric Relaxation
6) Rapid Filling
7) Reduced Filling
End Diastolic Volume
At the end of phase one when ventricular volumes are maximal
Isovolumetric
No change in ventricular volume
QRS complex
In ECG, signifies onset of ventricular depolarisation
S1, S2 and S3
S1 - closure of mitral and tricuspid valves
S2 - closure of aortic and pulmonary valves
S3 - ventricular filling, normal in children, pathology in adults
X descent
Atrial pressure initially decreases as the atrial base is pulled downward as ventricle contracts.
V wave
Atrial pressure gradually rises due to the continued venous return from the lungs.
T wave
ECG, ventricular repolarization
Dicrotic pressure
In aortic pressure curve, caused by valve closure
Isovolumetric relaxation
Although rapid decline in ventricular pressure, volume remains constant since all valves are closed.
Stroke volume equation
End Diastolic Volume(EDV) - End Systolic Volume(ESV)
Y descent
Fall in atrial pressure that occurs after opening of mitral valve
Diastasis
Initial passive filling of the hearts ventricles has slowed down
Acyanotic congenital heart disease types
Left to right shunts: ASD,VSD,PDA
Obstructive lesions: Aortic stenosis (Hypoplasia), Pulmonary stenosis (Valve, outflow, branch) Coarctation of the Aorta, Mitral stenosis
Describe the normal anatomy of the right ventricle
- Makes up most of the inferior border of the heart
- Trabeculae carnae
- Papillary muscles attach to chordae tendinae, connecting to the tricuspid valves
- Moderator band between the interventricular septum and the anterior wall of the RV: contains the right bundle branches which allow coordinated contraction of the
papillary muscles ● Outflow part (conus arteriosus) contains the pulmonary semi-lunar valve which
leads to the pulmonary artery. It has smooth walls ie no trabeculae carnae
Name the anatomical area in which the heart and pericardium lie, and state its borders
Middle mediastinum
Anterior border - anterior portion of the pericardium
Posterior border - posterior portion of the pericardium
Lateral border - pleura of the lungs
Superior border - imaginary line between the sternal angle and T4 vertebrae
Inferior border - superior surface of the diaphram