about starling's law....?

Question

hw do u explain starling's lawof tortoise heart(ventricle). hw do i discuss about it?...wats the effect of the law on the experiment..and also wats the effect of diastolic and systolic pressures?

Answer 1

starling law states that: the more increase in the muscle fibres, the more its power of contraction; WITHIN LIMITS (outside these limits the more increase the weaker contraction; ... which means over stretch & in this case heart failure)
it can b EXPLAINED according to molecular basis as the muscle fibres consists of actine & myosine fibres which r present opposite each other. muscle contracts due to sliding of actine over myosine, due to presence of something like receptors on them; a process which uses ATP.
these two types of fibres r not perfectly matched when muscle is relaxed & shortened, but when it stretches PASSIVELY before contraction, it becomes ideal (each part opposite its receptor) if over stretch again they doesn't match but in the opposite direction)
IN UR EXPERIMENT: the stretching force of muscle (heart) is blood (venous return) power of its contraction (ejection fraction) is reflected on the blood pressure esp. systolic.
i think ur tortoise is dissected & its heart is off so u can apply stretching force directly through adding weights to it via a hook fixed to it (as we did while we were students)

Answer 2

First of all, you'll get better responses if you type in a manner that people who know about Starling's law will be likely to read and respond. Let's at least TRY to use English.

The easiest way to explain Starling's law (or the Frank-Starling mechanism) is this: The more you stretch a cardiac muscle fiber, the stronger it contracts. That means, if the heart fills up with more blood, it stretches out the muscle fibers more, and the blood will be ejected with more force than it would if the volume was lower.

I can't speak to your experiment, of course, because you didn't give details.

If blood is ejected at a greater force, we can expect systolic pressures to be higher when the diastolic volume (and, presumably pressure) is greater.

I hope that helps.

Answer 3

The Frank-Starling law of the heart (also known as Starling's law or the Frank-Starling mechanism) states that the more the ventricle is filled with blood during diastole (end-diastolic volume), the greater the volume of ejected blood will be during the resulting systolic contraction (stroke volume). A diagram or a graph relating the length of the cardiac muscle in X-Axis and stroke volume on Y- axis should like a straight line that`s a diagonal to both X- and Y- axis within limits. The onset of heart failure removes the relation.

Answer 4

I agree with the gas-passer on this one: if you can't deal with the English language or state your experiment, it isn't likely you'll understand the Frank-Starling curve.
Up to a point, the longer the stretch of the myofibril, the greater the force of contraction. But there is a point, seen in people with CHF, where you stretch so far that you "fall off" the other side of the curve, and you've gone past the point of maximum return.

Answer 5

Starling`s law states " The more the initial length of the cardiac muscle fiber the more is the force of contraction".
This law is equally applicable to human and animal heart. Obviously within limits a dilated chamber contracts more powerfully. BP must increase.