Elizabeth Fernandez
Professor Richardson
General Biology 2 Lab Section 01
March 27, 2017
Comparative Sensory Physiology Lab
Introduction:
All animals have specialized receptor cells that are sensitive to certain inputs like sound, light and chemicals. When these receptor cells are stimulated a nerve impulse is sent across the body and into the central nervous system where the signal is perceived as one of the animals senses (taste, hearing, sight, smell, equilibrium, etc.). There are three different types of receptors: electromagnetic receptors, mechanoreceptors, and chemoreceptors.
In this lab we tested the mechanoreceptors and the electromagnetic (photo) receptors in an earthworm. To test the mechanoreceptors we separated the earthworm …show more content…
I hypothesized that segment one, the part containing the head and mouth, would be the most susceptible to such stimulation. The results of my experiment support my hypothesis. The reason why segment one is the most sensitive is because earthworms don’t have eyes so they need to use mechano and photoreceptors to perceive light and touch this is known as dermal light sensitivity. Dermal sensitivity is also the reason why the photoreceptors are distributed less to the tail part of the worm. Touch receptors are very important to earthworms because they need to be able to feel the ground they are crawling on. If the ground is too hot and dry the worm will desiccate, if it is too wet it will drown. Like the photoreceptors, the mechanoreceptors are distributed unevenly throughout the worm. This is because the worm crawls head first so the head must have the strongest receptors in order to tell where it is going or what it is crawling on. For example if the strongest receptors where in segment three, the worm would know too late if it was crawling on a dangerous …show more content…
There were flaws in our experimental design which resulted in slight errors in the results. We didn’t keep the duration of light exposure constant for each photoreceptor trial and we didn’t use the same number of strokes per segment during the mechanoreceptor test.
Conclusion:
My results failed to reject my null hypothesis that the stimulation of segment one would result in the most worm movement. I also expected segment five to have the least amount of movement for both receptors, however based on my observations I can conclude that that is partially false. For the mechanoreceptors, stimulation of segment 4 caused the least amount of movement in the
Professor Richardson
General Biology 2 Lab Section 01
March 27, 2017
Comparative Sensory Physiology Lab
Introduction:
All animals have specialized receptor cells that are sensitive to certain inputs like sound, light and chemicals. When these receptor cells are stimulated a nerve impulse is sent across the body and into the central nervous system where the signal is perceived as one of the animals senses (taste, hearing, sight, smell, equilibrium, etc.). There are three different types of receptors: electromagnetic receptors, mechanoreceptors, and chemoreceptors.
In this lab we tested the mechanoreceptors and the electromagnetic (photo) receptors in an earthworm. To test the mechanoreceptors we separated the earthworm …show more content…
I hypothesized that segment one, the part containing the head and mouth, would be the most susceptible to such stimulation. The results of my experiment support my hypothesis. The reason why segment one is the most sensitive is because earthworms don’t have eyes so they need to use mechano and photoreceptors to perceive light and touch this is known as dermal light sensitivity. Dermal sensitivity is also the reason why the photoreceptors are distributed less to the tail part of the worm. Touch receptors are very important to earthworms because they need to be able to feel the ground they are crawling on. If the ground is too hot and dry the worm will desiccate, if it is too wet it will drown. Like the photoreceptors, the mechanoreceptors are distributed unevenly throughout the worm. This is because the worm crawls head first so the head must have the strongest receptors in order to tell where it is going or what it is crawling on. For example if the strongest receptors where in segment three, the worm would know too late if it was crawling on a dangerous …show more content…
There were flaws in our experimental design which resulted in slight errors in the results. We didn’t keep the duration of light exposure constant for each photoreceptor trial and we didn’t use the same number of strokes per segment during the mechanoreceptor test.
Conclusion:
My results failed to reject my null hypothesis that the stimulation of segment one would result in the most worm movement. I also expected segment five to have the least amount of movement for both receptors, however based on my observations I can conclude that that is partially false. For the mechanoreceptors, stimulation of segment 4 caused the least amount of movement in the