Question

What is the effect of cold, warm, and room temperature earthworm ringer on the smooth muscle of an earthworm?

What is the effect of KCI on the smooth muscle contraction?

What is the effect of pilocarpine on a smooth muscle earthworm contraction?

Answer 1

Various experiments are performed to see the effect of varied temperature on the smooth muscle of the earth worm.

The large number of observations made during an investig@hion upon the effect of temperature changes upon the rate of contraction of the dorsal blood vessel of the earthworm, Lumbricus agricola, and indicate very clearly that the animal under investigation adapts itself with remarkable quickness and closeness to the temperature of its environment. In fact we think it may safely be said that the worm will adapt itself to a change of at least ten degrees Centi grade within two minutes, to an accuracy of 0.050 C. This fact makes it possible then to use the temperature of the water surrounding the animal as an indicator of the temperature of the animal, in the case of the earthworm, for experiments upon the temperature coefficient of heart action, and assures us that the worm need not be subjected to a bath of a given temperature for any great length of time in order to get an accurate result. It is very likely true that the same principle will be found to hold good for other animals of a similar kind and habit, certainly for marine worms, fish embryos, small crustacea, etc. It is the purpose of the authors to continue the investigation upon other forms in order to determine to what extent we may be at liberty to assume the temperature of the surrounding fluid to be an indicator of the temperature of the tissues.

Alternate contractions in these two layers create a wave of contraction that moves down the gut to push food toward the anus. Like cardiac muscle, smooth muscle is myogenic (i.e. contracts autonomically) and can create spontaneous waves of depolarization that result in waves of contraction.

Cells in the gut produce serotonin, a neurotransmitter that can act on the smooth muscles directly as well as stimulate nerve cells. It is one of the two neurotransmitters you will be studying. The other is acetylcholine (ACh). One of its functions is to stimulate gut contraction. There are also neurotransmitters that inhibit gut contraction. From this, it should be obvious that regulation of contraction in the crop gizzard is complex. As with striated muscle, calcium ions play an important but indirect role in the regulation of muscle contraction. They move into the cell through proteins in the cell membrane or sarcoplasmic reticulum known as calcium channels.

Let's briefly examine the role that ACh plays in muscle contraction

Alternate contractions in these two layers create a wave of contraction that moves down the gut to push food toward the anus. Like cardiac muscle, smooth muscle is myogenic (i.e. contracts autonomically) and can create spontaneous waves of depolarization that result in waves of contraction.

Cells in the gut produce serotonin, a neurotransmitter that can act on the smooth muscles directly as well as stimulate nerve cells. It is one of the two neurotransmitters you will be studying. The other is acetylcholine (ACh). One of its functions is to stimulate gut contraction. There are also neurotransmitters that inhibit gut contraction. From this, it should be obvious that regulation of contraction in the crop gizzard is complex. As with striated muscle, calcium ions play an important but indirect role in the regulation of muscle contraction. They move into the cell through proteins in the cell membrane or sarcoplasmic reticulum known as calcium channels.

KCL effect on smooth muscle contraction

Regulation of smooth muscle calcium sensitivity: KCl as a calcium-sensitizing stimulus. ... This KCl-induced stimulus-response coupling mechanism is a standard tool-set used in comparative studies to explore more complex mechanisms generated by activation of GPCRs.

Pilocarpine also acts on the ciliary muscle and causes it to contract. When the ciliary muscle contracts, it opens the trabecular meshwork through increased tension on the scleral spur. This action facilitates the rate that aqueous humor leaves the eye to decrease intraocular pressure.