hard · MCAT bio-biochem
An investigator infuses a positive inotrope that increases ventricular contractility without changing heart rate, preload, or afterload.
How does this shift the ventricular pressure-volume loop and the Frank-Starling curve simultaneously?
- The end-systolic pressure-volume line rotates leftward and steeper at every afterload, and the Frank-Starling curve simultaneously shifts upward at every preload.
- The PV loop widens only because end-diastolic volume itself rises, while the Frank-Starling curve stays unchanged since contractility is treated as a fully separate variable.
- The end-systolic pressure-volume relationship shifts rightward, lowering stroke volume, while the Frank-Starling curve shifts downward.
- Both curves stay unaffected because inotropic state only modifies heart-rate-dependent relaxation kinetics, never the pressure-volume relationship itself.
Sign up free to see the explanation and track your rank →
More MCAT bio-biochem practice
- What genetic term describes a single gene influencing multiple seemingly unrelated traits?
- In the human ear, sound waves cause fluid in the cochlea to… — Which cells are responsible
- An electrophysiologist observes a neuron at its resting memb… — Which ion is primarily res
- Which structure is most likely dysfunctional?
- Which organelle would you expect to be exceptionally well-developed in these cells?
- Which molecule acts as a 'fluidity buffer' in animal cell membranes?
- A scientist is tracking the movement of a secreted protein. If the protein has just left t
- A molecule moves into a cell against its concentration gradient using energy provided by a