How does the brain receive pain?
The brain receives pain through nociceptive stimuli which activates pain receptors on neurons called nociceptors. Nociceptors can be placed into two categories: A-delta (Aδ) fibres and C-fibres. A-delta fibres are small, myelinated, neurons that transmit signals fast and mediate sharp pain. C-fibres are smaller unmyelinated neurons that slowly transmit signals. They mediate dull, aching pain. Both types of fibres stimulate secondary neurons that establish the ascending pathway which projects to the Thalamus in the brain. Sensations of pain are controlled by the ascending and descending pathways in the central nervous system. The feelings of pain are conducted through the peripheral nerves, through the spinal cord and the brain stem and finally into the brain itself.
The Descending pathway
The descending pathway is triggered during pain. The is an example of …show more content…
These neurotransmitters also encourage the production of glutamate which can either excite or inhibit the function of neurones to either allow the body to be aware of the pain or to numb the pain. Bradykinin production is also reduced as it mediates pain associated with inflammation.
Opioid system
The opioid system consists of distant neurons that produce endogenous opioids such as: endorphins, enkephalins, dynorphins, endomorphins. These opioids act on opioid receptors on neurons [3], activation of opioid receptors in the brain can reduce the perception of pain by regulating the activity of the receptors allowing their activity and can produce analgesia. The opioid system also controls the reward and addiction pathway therefore suggests why opioid drugs such as Morphine are addictive.
Exogenous