We generally find it irritating and hard when we experience pain but scientifically pain is good for an individual. It helps to locate any ill effect inside the body that is generally left negligible by us. If the exterior of our body have any kind of wound or cut we immediately notice it and get the treatment on time, but the interior portion of the body is not seen by our naked eyes, and if no pain is raised in case of infection or any damage to cell or tissue, we would be unaware of it and hence lastly death may occur due to no treatment.
Therefore, it can be clearly said that pain is very important that helps to locate any distortion in the inner of the body. There are certain receptors for pain that are called nociceptors. These nociceptor are free nerve ending that can be found in any tissue of the body excluding the brain. There are certain differences between the normal sensory neuron and the neurons for pain. Firstly, these neurons have no specialized ending like that of normal sensory neuron rather they have free nerve ending. Secondly, nociceptors are non- myelinated and the conduction is very slow in comparison to normal sensory neurons which are myelinated and conducts the impulse fast.
The signal for pain travels through the spinal cord and reaches the gray matter where synapses of neurons are established. The synapses occur within and outside the spinal cord. Now, the secondary neuron sends the message towards the upper portion that reaches the white matter. Therefore, form the spinal cord the information travels upward passing through the medulla and reaches the relay centre of the brain. Now when the information reaches the parts of the brain processing of the information is done. Finally, the result then moves downwards the motor cortex generating the impulses or the reactions.
1. Fast pain: this is the pain that travels faster and rapidly within some seconds and is very acute. This pain is generally not felt in deeper parts or tissues of the body.
2. Slow pain: this is the pain that travels slowly after a minute or more when the stimulus is applied to it. This pain is felt both in the inner portion of the body as well as the outside the body.
Presently, there are several medicines and drugs that help to get relieve from pain and get back the body in normal condition.
Thermo means the temperature; therefore thermo receptor refers to the sensory receptor that is sensitive to the change in temperature. Temperature can be either warm or the cold, the receptor for warmth are located in dermis whereas that of cold are located in the stratum basalae of the epidermis. Other organ for thermo reception is urinary bladder and cornea. The main area for thermo reception or thermoregulation is the hypothalamus present in the brain. The temperature 10 – 40 degree activates cold receptor whereas the temperature 32 – 48 activates warm receptor. The neurons of this receptor have free ending rather than any specialized ending. Skin is the main organ for thermo reception along with cornea and urinary bladder. When any stimulus related to this is received, it travels the spinal cord, from there the message is send to the lissauer’s tract where it synapses with secondary neuron that is present in the gray matter, and slowly it then joins to spinothalamic tract extending to the ventral nucleus of the thalamus.
Thermo reception and pain are both important for the body since they help to sense the external stimuli and react accordingly.