why does the maximum contractile force generated by heart increase with preload?

why does the maximum contractile force generated by heart increase with preload?

Expert Solution

maximum contractile force generated by the heart will increase with preload

This can be explained by the frank-starling law

preload of the heart is related with ventricular filling. when the blood fills up the ventricle it result in the stretching of cardiomyocyte present in the ventricles.

stretching of the cardiomyocyte is the increase in the length of the muscle fibe. when the length of the sarcomere is increased, it causes an increase in the tension created in the muscle cell, this called the muscle contraction.

The increase in the muscle contraction occurs due to change in the overlap of actin and myosin filament. the maximum contraction occurs at a optimum length (preload).The increase increase in muscle contraction is due to the increases sensitivity of the calcium ions towards the troponin.This result in the increased formation of actin myosin cross bridge. so more amount of calcium is released from the sarcoplasmic reticulum.Also there is decreasei n spacing of the actin and myosin filaments. Hence the muscle contraction is increased.

Sydney Mullin answered 1 year ago

PROBLEM #3 INTRODUCTION: The contractile performance of heart muscle depends on its inotropic state, preload and...

PROBLEM #3 INTRODUCTION: The contractile performance of heart muscle depends on its inotropic state, preload and afterload. These factors also determine the stroke output of the heart. In vivo, the aortic pressure, the pressure against which the left ventricle must pump, is the main afterload. If the outflow resistance of the aortic valve should increase, however, it too can impose a significant afterload on the ventricle. Use the following websites to understand what preload and afterload are and how they...

how does cardiac muscle regulate contractile force?

Compared to a normal heart, in left heart failure, why does ESV and EDV increase?

How action potentials are generated and propagated in contractile cardiomyocytes..

Why does heart WEIGHT increase with body weight? detailed answer please

Briefly define the following terms: Preload Afterload Starling’s law of the Heart

Why does potassium affects the heart rate?

Explain how what would be the physiological impact of tetanus to heart function and how contractile...

Explain how what would be the physiological impact of tetanus to heart function and how contractile cardiomyocytes avoid tetanus./

What is the function of the contractile vacuole in paramecium caudatum. ? Why is this an...

What is the function of the contractile vacuole in paramecium caudatum. ? Why is this an important function? Are these organisms autotrophic, heterotrophic, or mixotrophic? Explain how you know.

Congestive Heart Failure Identify pharmacologic agents for diuresis to reduce preload. Identify positive inotropes. Identify phosphodiesterase...

Congestive Heart Failure Identify pharmacologic agents for diuresis to reduce preload. Identify positive inotropes. Identify phosphodiesterase inhibitors. Describe the mechanism of action of ACE inhibitors. Describe the mechanism of action of Human B-type natriuretic peptide. Describe the mechanism of action of Angiotensin II-receptor blockers. Which of these agents is the most commonly used for left sided heart failure? Right sided heart failure? You may use narrative writing or a table to answer these questions.

Question