Heart Patho Flashcards
Where is the tricuspid (AV) valve located?
Between the right atrium and the right ventricle
Where is the bicuspid (AV) valve located?
Between left atrium and the left ventricle
When blood is ejected from the left ventricle, what valve does it pass through?
Aortic (semi-lunar)
When blood is ejected from the right ventricle, what valve does it pass through?
Pulmonary (semi-lunar)
When does the heart get perfused, during systole or diastole?
Diastole = b/c the force of systole opens the aortic valve but during diastole the aortic valve closes and there is some backflow of blood that fills the coronary arteries
When does atrial systole occur?
During ventricular diastole
What is the correct flow of conduction through the heart?
- SA node
- AV node
- Bundle of HIS
- Right and left bundle branches
- Terminal Purkinje fibres
How many types of pacemaker cells are there?
- SA node (60-100 bpm)
- AV node (40-60 bpm)
- Specialized ventricular pacemaker cells (20-30 bpm)
What has to be stimulated in order for the ventricles to contract?
Terminal Purkinje Fibres
What is the formula for cardiac output?
CO = HR x SV
What is stroke volume?
Volume of blood that is ejected from the heart with each beat
SV = EDV - ESV
What are the three things that affect stroke volume?
- Preload
- Afterload
- Contractility
What is preload?
Amount of stretch that the ventricles have
- when the heart is filling with blood
What happens to CO when preload increases?
As preload increases, stroke volume increases = cardiac output increases
What is afterload?
Pressure in the arteries above the semilunar valves
What happens to CO if afterload increases?
As afterload increases, stroke volume decreases = cardiac output decreases
What is the Frank-Starling Law?
The greater the amount of stretch in he heart, the greater the force of contractility
Define ejection fraction
Percentage of blood that is ejected from the heart during each contraction
How is EF calculated?
Stroke volume divided by end diastolic volume
What is important about the SA node?
Initiates the electrical impulses for cardiac contraction
What does S1 signify?
Closure of AV valves
- beginning of systole
What does S2 signify?
Closure of SL valves
- End of systole
Where can you best hear S1?
Near the apex of the heart
- tricuspid = right side
- bicuspid = left side
Where can you best hear the pulmonary valve closing (SL)?
2nd intercostal space
- LEFT side
