The Univeristy of Melbourne The Royal Melbourne Hopspital

A joint venture between The University of Melbourne and The Royal Melbourne Hospital


30 Nov 2020

Setting it Straight: Sensing and responding

Setting it Straight - Issue #35

The higher vertebrates have two immensely complex (and still partly understood) internal networks that operate to recognise, and respond to, a seemingly limitless diversity of specific challenges to our health and wellbeing (#19). Only one, the nervous system (NS), functions at the level of consciousness, though rational decisions concerning, say, medical interventions, can affect the operation of the other, the immune system (IS). Simplistically, neurological input reflects that chemical/electrical signals travel along nerve fibres following the activation of various sensing receptors located in the eyes, the ears, the nose, the skin (for pain, pressure, heat, cold) and so forth to register in that central processing unit (CPU) we call the brain. The resultant perceptions of pleasure, pain, danger, safety, or some other familiar sensation or situation causes us to make choices expressed via outgoing signals that speed along other nerves to innervate the muscles of, for example, the mouth (smile, grimace) or the legs and arms (fight or flight), leading to a response that seems right for that time and place. Later, we may, as humans, reflect on, even agonise, about the choice we made. Do other animals ever do that? I’ll leave that question to the neuroscientists!