Why human needs pain? Isn’t it good when one can’t feel pain?
Things happen in human for a reason. Structure follow function. It it is available in human then there must be somekind of function for it.
I am talking about the physical pain, emotional pain is more difficult to explain.
Pain is mechanical. There are receptors in our body to feel pain (called as nocireceptors). Why do we feel pain? To warn your body.
For example, your fingers touch hot pan and the normal reaction would be reflex to take the finger from the hot pan to avoid pain. It would be very bad when you don’t have pain. Congenital analgesia, is one or more rare condition in which a person cannot feel (and has never felt) physical pain (wikipedia). Imagine that, if you can’t feel pain when your finger are touching that hot pan, you will not realize that it hurts your finger (maybe until you see your finger is burnt?). Therefore it acts like a warning signal for the body.
The mechanism goes as follows:
Nociceptors are the specialised sensory receptors responsible for the detection of noxious (unpleasant) stimuli, transforming the stimuli into electrical signals, which are then conducted to the central nervous system. They are the free nerve endings of primary afferent Aδ and C fibres. These different nerve ending differ in the threshold. Meaning some are sensitive to pain some need the pain to be somewhat painful enough to be felt. (if that makes sense). These different receptors acts differently. The get-away-from-hot-plate type of reflex need quick response, also the receptors works for different kind of stimuli: mechanical, thermal and chemical. The stimulus accepted from the receptors are processed and if they get over the threshold then they will be brought to the brain via 2 tracts:
” 1. The spinothalamic tract: secondary afferent neurones decussate within a few segments of the level of entry into the spinal cord and ascend in the contralateral spinothalamic tract to nuclei within the thalamus. Third order neurones then ascend to terminate in the somatosensory cortex. There are also projections to the periaqueductal grey matter (PAG). The spinothalamic tract transmits signals that are important for pain localisation.
2. • The spinoreticular tract: fibres also decussate and ascend the contralateral cord to reach the brainstem reticular formation, before projecting to the thalamus and hypothalamus. There are many further projections to the cortex. This pathway is involved in the emotional aspects of pain” (1)
The link below could show you the pathway of pain. Which I really like because I wanted to know about neural pathways. Pain is rather well understood by now.
Blog entry for Ramadan day 10
- An introduction to pain pathways and mechanisms. accessed 6/16/2016https://www.ucl.ac.uk/anaesthesia/StudentsandTrainees/PainPathwaysIntroduction
2. Mechanism of pain. accessed 6/16/2016 http://www.ncbi.nlm.nih.gov/books/NBK32659/