Sensory Systems: Touch - Research Paper Example

Sensory Systems: Touch Introduction Somatosensory system, which is made up of processing centers and receptors is a sensory system that deals with sensory modalities including touch, proprioception, temperature, and nociception. Skin, which acts as a barrier between a person’s body and the environment, provides the brain with a lot of information such as temperature, pressure and pain among others, about the environment that people live in. Sensory receptors are placed on the skin, muscles, skeleton, joints and bones, cardiovascular system and other internal organs. In terms of medicine, the sense of touch is referred to as somatic sense. The system that is associated with touch is activated by several stimuli, which include nociceptors, thermoceptors, chemoreceptor, and mechanoreceptors. Information is transmitted through sensory nerves in the spinal cord to the brain (Chapman 580). On the other hand, the information is processed in primary somatosensory area, which is located in the parietal lobe a part of the cerebral cortex. It is of paramount importance to note that touch can be used in the identification of objects in the absence of vision. This can be attributed to the fact that the brain is able to deduce the shape of an object from the information it receives from the hands or other parts of the body. It would be very difficult to live without touch because it helps one to feel when moving, through his/her feet, or sense something that is sharp when pressed against the skin. Although many people relate touch to the skin only, it has to be noted, that touch occurs in the body that leads to the feelings of pain in the body such as stomachaches and headaches. In addition, unlike other sensory systems in the body, touch is located in the entire body while the other senses are localized in definite areas. This is because touch plays numerous roles in ensuring that the body stays out of danger (Chapman 579). Physiology of Touching The skin has about five million sensory nerve receptors, which are used to relay different information to the brain via the spinal cord. Touch sensors, after stimulation will send electrical pulses to a person’s neurons. Neurons are special cells, which have the ability to send electrochemical impulses. The work of the sensory neurons can be related to that of a relay team. This is because electrical pulses are sent from one cell to the next until it reaches the spinal cord. The spinal cord is the one responsible for taking the electrical impulses to the brain where the latter translates the signal. It is worth noting that the brain combines all the messages it has received in order to come up a conclusive translation. Although the message send from some parts of the body such as the feet, may have to travel for two meters, it is worth noting that the message is transported in a fraction of a second (Chapman 580). Some of the senses of touch that the brain may receive can be in the form of a message, which is associated with uncomfortable tight fitting shoes, which the brain translates to pain. In such a situation, the brain will instruct the feet muscles to curl in order to reduce the pain. On the other hand, when one is placed at a very cold place, the brain is activated. The brain in return may instruct the body to start shivering in a bid to generate some heat for the body. The brain has the abilities of combining different messages from different sensory receptors and translates it. In addition, although all the other senses, which are hearing, smell, taste, and sight, are located in particular areas of the body, touch happens to be all over the body. This can be attributed to the fact that touch originates from the lower layer of the skin, which is referred to as the dermis. The dermis has a large number of tiny nerve endings, which provide information about the objects, and feelings that the body comes in to touch with (Chapman 570). The nerve endings have the abilities of telling the body that a certain object is hot or cold, or is causing pain. The highest number of receptors in the body is that of pain, cold, heat, and pressure. The most important receptors in the body are those that warn the body about pain because they end up saving people from injuries. It is of paramount importance to note that different areas of the body have different sensitivities. This is because the number of nerve endings is not distributed evenly around the body. For example, the tongue has very many nerve endings for detecting pain than for detecting heat. This is the reason why one will experience immense pain after hurting the tongue as opposed to when eating something very hot (Chapman 568). The body has more pain nerve endings compared to any other type. These endings are used to protect the body from harm. In addition, it has to be noted that the middle of the back is the least sensitive part of the body. On the contrary, the most sensitive areas of the body are lips, hands, face, tongue, neck, feet, and the fingertips. Fingertips have around one hundred touch receptors. This implies that these areas are used by the body severally for one’s safety (Chapman 562). Neurology of Touch The Somatosensory cortex senses even the minutest movements that are made by the body. It has to be noted that one manipulates the environment in order to be in control of the simplest actions that one engages in. It is of paramount importance to note that touch enables one to gauge the energy needed to hold a cup at the right grip so that it does not fall off the hand or break because of compression. This is made possible by the use of mechanoreceptors, which are systems that respond to skins’ deformities (Klatzky 302). For example when the blind are reading Braille, they strike a certain letter such as A that results in indention of the fingertip. This indention is recorded by several nerve endings and each sends its message to the brain. When the information reaches the brain, it is translated to a recognizable figure, which is A, by the reader through neuronal firing. In addition, vibration receptors are located deeper in the skin and they behave more or less like auditory receptors. This is the reason why auditory and vibration is handled at close proximity in the brain (Klatzky 301). Nociceptors are very helpful to the human being because they help one in detecting heat. Cold receptors are used for reporting information that relates to cold while warmth receptors are for detecting heat only. It is worth noting that these receptors have the abilities of sensing temperature changes of as a little as a hundredth of a degree Celsius. When temperature is too high, it causes pain to the body and pain receptors take over from heat receptors to report to the brain about what is happening (Klatzky 299). Every part of the body has the above-mentioned types of receptors while others have more. Some receptors could be found on hairy body parts but lack non-hairy parts. When touch signals reach the brain they are sorted according to the information they are delivering which could be heat, pain among others. In addition, the speed is used to measure the intensity of the signal. Columnar brain structures are used to make precision on the type of message being delivered as the signal moves deeper to the columns. After interpretation, coded messages are sent to other parts of the brain. When a Braille reader touches letter A, the brain must have a template of an A which it uses to compare it with the received information to deduce the meaning of the received message (Klatzky 300). Functions of Touch The most important function of touch is helping the body to stay away from hurting environments. When a person touches a very hot or cold object, signals are sent to the brain and the person is able to release the object before it does a big damage. On the same note, when a person steps on a sharp object s/he will be able to leap before the object causes a deep incision in the body and reduce the damage that could have been caused by that object. A person will run out of a place that is extremely hot because the brain will tell the body the impending danger (Williams and Bargh 606). The blind, because of the fact that they cannot see, use their sense of touch in accomplishing most of their day-to-day activities. The blind are able to read Braille and perform other duties such as bathing and washing their clothes because through touch they are able to differentiate objects. This implies that the lives of such people would have been very difficult were it not for the sense of touch which delocalized across the whole body. One is able to learn the texture of a given object through touch. Sharp objects that can hurt a person will be felt too and the blind person will be able to stay away from them (Klatzky 300). Scholars have been avoiding the importance of touch in communication, but it has to be noted that it plays a crucial role. Touch has phylogenetic primacy qualities in the sense that during evolution it was used as a means of communication before the development of verbal communication. People will often result in using nonverbal means of communication especially during times of stress. This implies that because man, as he was on the course of evolution and there was no language, touch played a significant role in transmission of information and feelings (Klatzky 299). On the other hand, touch has ontogenetic primacy, which implies that at the early stages of life, nonverbal communication is more important than verbal communication. When an infant is born, touch remains as the best form of communication and continues to play the same role for the first year. Through touch, it is possible to regulate physiological states, help in normal biological and social development. This can be attributed to the fact the tactile system aids in the development of all other forms of communication. Infants develop attachments to their mothers through touch and they are able to learn other things once they are left alone. This is the reason why infants are seen touching objects that are around them as they try to understand them (Williams and Bargh 606). Touch plays a significant role in the promotion of cooperation and trust. The insular cortex, which is activated by physical touch, is also active during feelings of trust. This shows that the two are interrelated. In addition, physical touch results in reduced feelings of anxiety and threat. Touch can be used to soothe the aggrieved because it shows one that the people around him/her care. Working in a team involves bonding because the performance of the team is dependent on the performance of each individual. Touch results in bonding which in turn improves performance in a given team (Williams and Bargh 607). On the other hand, touch plays a fundamental role in the improvement of sexual relationships. This is the reason why touch increases as a relationship moves from impersonal to personal. People feel loved when they are caressed by their partners and this increases trust among the partners. In addition, the partners will relieve stress and anxiety when they engage in physical touches (Williams and Bargh 606). Conclusion Communication between the sensory nerve receptors and the brain via the spinal cord ensures that one is able to understand the environment he/she is in. This can be attributed to the fact the body senses even the smallest changes in the environment. These changes include temperature, pain, textures among others. Touch has several fundamental roles to play in the body. This is the reason why the whole body has sensitivity to touch as opposed to other senses, which are localized in certain areas in the body. However, it has to be noted that different parts of the body have different levels of sensitivity to touch. This can be attributed to the fact that the number of sensory nerves varies from one body area to the other. This shows the reason why one will have very sensitive parts of the body such as his/her hands as opposed to the back. In addition, the sense of touch plays a fundamental role in communication especially for infants during their early years of development. This is because the tactile system develops before all the other forms of communication. Works cited Chapman, Calvin E. "Active versus passive touch: factors influencing the transmission of Somatosensory signals to primary somatosensory cortex." Canadian Journal of Physiology and Pharmacology, 72.5.1994, 558-70. Available Klatzky, Roberta L. Identifying objects by touch: An "expert system" Perception & Psychophysics, 37.4, (1985): 299-302. Available Williams, Leornard E, & Bargh John A. Experiencing physical warmth promotes interpersonal warmth. Science, 322.5901, (2008): 606-7. Available Read More