Which parts of human body are non painful when we cut them?
Pain is a function of neural response. When some part of our body get ruptured then ruptured cells of that part transmit strong neural messengers to brain cells that generate a sensation of pain. This signal transduction mechanism is same in every living creature including animals, so when we beat animals or slaughter them to eat it is equally painful for them also.
This article will try to example that why few parts of human body are not capable of generating painful sensation. In human body nails and hairs are two special parts that don’t generate pain when we cut them.
Normal human body posses 20 nails and no human being experience pain while cutting his/her nails. In fact it a normal hygiene exercise to cut nails at regular intervals. Cutting of nails never generate pain simply because they are structured through dead cells. They contain a very hard material called as keratin which is a type of attenuated protein. The roots of nails go deep inside the skin and elastic fibers of skin keep them at their fixed position. The area near the roots of nails is semicircular and white in appearance. Cutting the nails from edges never generate any pain because they are not part of signal transduction phenomena. But when we remove a complete nail from finger, it generates intense pain because elastic fibers of skin beneath the nails undergo disruption in the process. Moreover roots of nails are active part of signal transduction. So they produce instant pain messengers on disruption that generate intolerable sensation of pain. Normally nails grow at a rate of 1.9 inches per year.
Hairs are actually thread-like composite structures made up of keratin. Due to their structure they are not attached with any signal transduction linkage of body. So, we don’t feel any pain when we cut our hairs. Roots of hairs go deep inside skin, so when we remove them from roots it does generate a sensation of pain. Normal growth rate of hairs is 14 mm per month and around 45 hairs fall on a normal day. Maximum age of a hair on the head is 3 continues years after which the hair falls out simply to create space for a fresh one. As a bonus point, this article will also explain that why some people have straight hairs but other has curls. It is the shape of follicles (spaces in skin from where hairs grow out) that determine the appearance of hairs. So, follicles make one’s hairs curly, wavy or straight.