There is definitely no shortage of information and vocabulary to unpack regarding the senses. Therefore, at the 50,000 foot level, this post will cover some basics info about three of the five major senses: auditory, somatosenses, and olfactory. In addition, I will briefly explore the idea of additional senses that don’t quite fit into the original five, yet are associated.
Auditory sense: The components of our auditory sense are not only quite complex, but our ear structure alone could be covered in an entire book—or so I’ve heard. (pun intended). From the intricate connections among ossicles, malleus, and tympanic membrane in the middle ear, to the cochlea’s interaction with the basilar membrane in the inner ear — auditory sensory information, as with other neurological processes, must go through a series of checkpoints to communicate with the auditory cortex within the temporal lobe.
For instance, the cochlea is a key component that helps convert auditory input into a liquid mechanism understood by the brain. Additionally, the cochlea has hair-like cells, called celia, with receptors that help transport audition to the brain via bipolar neurons and a common cellular process of attaching dendrites to synapses.
Next up – Somatosenses: This section was quite stimulating to me. (pun intended again). The skin, which functions as an organ in itself, relies heavily on cutaneous senses. These particular senses have to parse out different forms of contact – e.g., a touch on the shoulder, putting a cold glass up against your forehead, rubbing your hands together when you are cold, dealing with many forms of pain, etc. – and then activate receptors to form a kinetic response. For instance, mechanoreceptors are neurons that facilitate touch response, mostly from pressure applied to the skin.
Now, hold your nose for this next one (yes, I’m on a roll today.) – the Olfactory Sense: Our olfactory sense, similar to our visual sense, has a heavy infrastructure of receptors that employ bipolar neurons across a pattern of dendrites attached to synapses. This appears to be a common pattern with all of the senses: cellular and neuron processes are always involved with attaching sensory information to receptors and processing them accordingly. Also, from one of the first stops inside the olfactory bulbs, axons engage various parts of the brain, including the limbic cortex and the hypothalamus.
And I now am sensing another sense (Ok, I’ll quit now, I promise.) — Proprioception. Basically, this sense allows you to make movements without visually paying attention to every single one of them. Example: Your alarm goes off in the morning, and instead of opening your eyes and looking at the alarm clock to hit the snooze button (for the sixth time in a row), your perceived sense of space takes over and knows how to approximate where the button is located.
Makes sense? (Sorry, I couldn’t resist.)
Carlson, N. R. (2013). Physiology of Behavior (11th ed.). Retrieved from https://phoenix.vitalsource.com
Bradford, A. (2017). The Five (and More) Senses. Retrieved from https://www.livescience.com/60752-human-senses.html