Skin Receptors Reaction To Pain

How do skin receptors' distribution change one’s reaction to pain in different areas of your body?
Aim:
Our senses are responsible for receiving information in the outside environment and sending it to our central nervous system, where this information is then interpreted. Organs such as the skin, known as sense organs, have specific neurons named receptors, which are each responsible for responding to specific types of stimulus. The receptors responsible for identifying our sense of touch are distributed over the skin entire surface area. However the receptors are grouped together closer in some specific areas of the body compared to others. Not only that but these receptors also may be more sensible in one area and therefore respond more
severely to receptors in an alternative part of the body.
Throughout this investigation we will need to study the concentration in different parts of the human body of receptor cells. We will be taking samples of the body’s response to stimulus on the outside of your forearm, the upper back and the index fingertip, document it and afterwards analyze it.

Research: The skin in our body has a network of nerve endings and touch receptors in our skin that are part of the somatosensory system; it is responsible for the control of the sense of touch in our body. This is responsible for all the sensations we feel, such as cold, warmth, smoothness, roughness, pressure, tickles, itches, pain, vibrations, etc. In the somatosensory system, there are four main types of receptors called, the mechanoreceptors, the thermo receptors, the pain receptors, and the proprioceptors. A touch receptor is considered rapidly adapting if it responds to a change in stimulus immediately. However, rapidly adapting receptors can't sense how long the skin is touching an object, they sense best the vibrations that occur on or inside the skin. A touch receptor can be considered slowly adapting if it does not respond to a change in stimulus as fast as is considered normal. These receptors are very good at sensing a nonstop pressure of an object touching or nicking the skin but are not very good at identifying when the stimulus started or ended. There are 4 different receptors the mechanoreceptors, the thermoreceptors, the pain receptor and the proprioceptors. The Mechanoreceptors recognize sensations such as vibrations, texture, and pressure. The Pacinian corpuscles, Ruffini's corpuscles, Merkel's disks and Meissner's corpuscles are four known types of mechanoreceptors whose purpose is to identify indentions and vibrations of the skin. The most sensitive mechanoreceptors are the Merkel's disks and Meissner's corpuscles, which are found in the top layers of the dermis and epidermis, generally in non-hairy skin such as the tongue, palms, the soles of feet, fingertips, the face, lips, and eyelids. Merkel's disks are slowly adapting receptors while Meissner's corpuscles are rapidly adapting receptors therefore the skin can known when it is touching something and how long the it is touching the skin. Your brain gets information about the feel of objects through your fingertips because the ridges of the finger (our fingerprints) are full of these sensitive mechanoreceptors. Deeper in the dermis and with the tendons, joints, and muscles are Pacinian corpuscles and Ruffini's corpuscles. These mechanoreceptors feel sensations and vibrations traveling down your bones and your tendons, your rotational movement of limbs, and the stretching of your skin. Helping the ability to do physical activities such as walking and or throwing a ball in basketball game.
Thermoreceptors recognize sensations related to the temperature of objects in the skin, found in the dermis layer of the skin, there are two groups of thermoreceptors: hot and cold receptors.
The Cold receptors start to understand cold when the skin’s surface drops below 35°C, but are most alerted when the surface of the skin is at 25°C and stop being stimulated when the surface of the skin drops below 5°C. This is why one would feel their hands or feet start to go numb when submerged in extremely cold water for a long period of time. The Hot receptors start to identify hot sensations when skin’s surface rises over 30°C and but are most alerted when at 45°C. But past 45°C, pain receptors take over the senses to avoid any damage from being done to the skin and it’s underlying tissues. The Thermoreceptors can be found all over the body, however cold receptors are found in a greater concentration than its opposed receptors. The face and ears have the highest concentration of thermoreceptors, which is why the nose and ears get colder at a more rapid rate than the rest of your body in low temperatures. Pain receptors or nocireceptor detect pain or stimuli that causes any damage to the skin and/or any other tissues in our body. The body has over three million pain receptors, which are found in bones, skin, muscles, some organs and blood vessels. They are able to detect pain caused by mechanical stimuli, such as a cut or a scrape, chemical stimuli like a poison from an insect sting, or thermal stimuli such as a burn. The receptors cause a feeling of sharp pain so that the brain knows that the body needs to move away from a harmful stimulus such as a hot stove stop or a broken piece of glass immediately. They are also responsible for causing a dull pain in an area that has been recently injured so the body knows not to use or touch body part or member until the area has healed. These receptors play an important part in keeping the body safe from serious injury or damage by
sending early warning signals to the brain before injuries can worsen. The proprioceptors receptors sense the position of the different parts of the body relative to each other and it’s environment. The proprioceptors are found in muscles, tendons, and joint capsules, the location in the body is able to allow these special cells to be able to spot variations in muscle tension and muscle length. Without the proprioceptors, the body would not be able to remember to do things such as eating or clothing itself. We have many receptors in our skin however one specific one is never the only one active when we feel something. When you sense something with our skin we are able use many at the same time, so we can know how long, how strong we are holding something, if it hurting us, if it too hot or too cold. However some parts of our body has a larger density of receptor cells than others, as we have seen, our face has more thermoreceptors than in other parts of our body, and our finger tips have more touch receptors, which is why our fingers have the ridges for a our finger tips to facilitate the sensing of our skin. All these are signaled to our central nervous system, including our brain and spinal cord. So the brain can be alerted of what is going on with the rest of our body and how it can protect it from harm.

Hypothesis With Background Info
If I use the apparatus made out of toothpicks and apply even pressure to it while it is on my colleague’s skin whilst his/her eyes are closed then we will notice that the skin on the upper back and outer forearm will be the less sensitive ones while the index fingertip will be the most sensitive one, therefore he/she will feel less pain this will happen because the skin on your fingertips has more receptor cells than in other parts of the body, which are in charge of registering what is happening on the surface of your body and then sending signals to your spinal cord and brain, therefore the brain will be more aware of the pain in these areas