T3 L9: The cardiac pressure-volume cycle Flashcards
What is the circle of Willis?
Arteries on the inferior brain organised in a circle that provide a redundancy of blood flow
What % of cardiac output goes to the kidenys?
20-25%
Which organ produces ACE, Erythropoietin, and Renin?
The kidneys
What does adrenergic input do to skeletal muscle circulation?
Vasodilatation because muscles are associated with the fight or flight response
What are the 4 sequential events of the cardiac cycle?
- Ventricular filling
- Isovolumic ventricular contraction (Pressure is created but there is no actual contraction)
- Ejection (actual contraction)
- Isovolumic ventricular relaxation
What is a Wiggers diagram?
A cardiac diagram used to teach physiology
What is the Dicrotic notch?
A dip in a cardiac diagram indicating the closure of the aortic valve. It happens after ejection
What is S1 on a cardiac diagram?
The Lup sound. It indicated the mitral valve closing during isovolumic contraction
What is S2 on a cardiac diagram?
The dub sound. Isovolumic relaxation
When does the aortic valve open?
After isovolumic contraction (when the heart fills up). With a health heart, there wont be a sound made
When does the mitral valve open?
At the end of isovolumic relaxation (when the heart is empty)
When does the P wave occur?
Right before the heart starts filling
On a pressure-volume loop, describe where Ejection, Isovolumic relaxation, Isovolumic contraction and Filling are
IVR, ejection, IVC and filling in a clockwise direction
What does a pressure-volume loop look like with mitral stenosis?
Decreased preload and decreased afterload. The whole loop will be to the left because there is a lower volume of blood.
What is mitral stenosis?
A narrowing of the mitral valve opening
