Touch ReceptorsHow does your body feel things? Shakira Onwuachi Anatomy 1st Period
Hypothesis Experiment Description If the distance increases then the touch sensation in the arm will increase. The touch receptors in the forearm are close together. Reason: To find out how close and how far apart our touch receptors are in the forearm.
Background Knowledge • Originates in the bottom layer of the skin, the dermis, below the epidermis, the outermost layer of the skin. • Dermis is filled with tiny nerve endings that registers info. • Carries info to the spinal cord • Found all over in clusters around the skin. Onion or jelly material. Not distributed evenly. • When squeezed, layers rub against each other creating electrical nerve impulses.
About 20 touch receptors • Common: heat, cold, pain, pressure • Sensitive: hands, lips, face, neck, tongue, fingertips, chest, upper arm, sole of feet, and between the legs. • The more nerve endings = the more sensitive • Mechanoreceptors tell about sensations of pushing, pulling, and movement • Free Nerve Ending, Pacinian Corpuscle, Messiner Corpuscle • Thermoreceptors tell about sensation of temperature. • Krause Corpuscle, Ruffini Endings
Materials • Paper clip • Ruler • Data table • Pen
Data Collecting Procedure • Pick 10 people randomly • Explain the reason for the experiment • Straighten the paperclip and make it into an u-shape • Lay their arm flat with the inner-forearm facing up • Without the person looking, poke randomly along the forearm lightly. • Record whether or not they could feel one or both ends (if they noticed the difference). Also note if their guesses where wrong or right. Repeat increasing the distance 1 cm each time. • Suggested: 5 cm
Data Table & Variables Length (cm) Person
Results Length (cm) Person
Analysis & Conclusion My research shows that the distance of the touch receptors varies in the different parts of the body. As the distance of the points of the paperclips increased, people were able to tell the difference between one poke or two pokes. I have come to the conclusion that the touch receptors in the arm are about four cm. apart. From the research and this experiment, I learned that touch receptors are abundant. Some faults may have been the distance inadequately measured, people may have been looking, or simply their touch receptors where off.
Bibliography • Auyeung, Freda. “Touch.” The Five Senses.http://freda.auyeung.net/5senses/touch.htm (2 Dec 2007) • Childs, Gwen V. “Touch and Position Sensory Receptors.” Microanatomy Web Atlas.http://www.cytochemistry.net/microanatomy/nerve/touch_and_position_receptors.htm (3 Dec 2007) • Hartzog, Kevin C. “Touch.” Kevin C. Hartzog's WEB site.http://www.starsandseas.com/SAS%20Physiology/Neurology/Touch.htm (4 Dec 2007). • “Mechanoreceptors.”http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/M/Mechanoreceptors.html (3 Dec 2007) • “Touch Receptors.”http://fig.cox.miami.edu/~cmallery/150/neuro/c7.49.3.skin.jpg (8 Dec 2007) • “Touch: Your Sense of Touch.” Think Quest.http://library.thinkquest.org/3750/touch/touch.html (2 Dec 2007) • “Sensory Receptors.” Site Seeing.http://library.thinkquest.org/05aug/00386/touch/index.htm(5 Dec 2007)