Exploratory System

When the coffee is finished, our coffee maker’s beeping creates pressure changes, which move away from the machine and radiate to the individual’s location across the room. The waves reach the outer ear, which contains structures known as the pinnae, angled such that sound waves bounce off them and resonate. They enter the auditory canal after being significantly amplified before reaching the tympanic membrane. The waves strike the membrane and cause it to vibrate, which subsequently transmits them to the middle ear. The ossicles are three bones (malleus, incus and stapes) of the middle ear through which the vibrations pass. The stapes transmits the vibrations to the membrane-covered oval window successfully through balancing pressure, which
The inner ear contains the cochlea, filled with fluid essential to sound transmission. Stapes movement on the oval window causes the liquid to vibrate and travel up the spiraling structure, passing through the upper (scala vestibuli) and lower portion (scala tympani) to the round window, causing movement of the basilar membrane. This triggers movement of the organ of Corti, which contains cilia (hair cells) that bend from the subsequent, horizontal movements of the neighboring tectorial membrane. Cilia collectively bend due to their junction by tip links, opening ion channels in the cell, creating an inward flow of ions, while returning to their original position to close the ion channels. Repeated bending results in alternating transmission of electrical signal which releases neurotransmitters from the cells across the synapse to auditory nerve fibers. The signals are sent through a series of subcortical structures: the cochlear nucleus, superior olivary nucleus in the brainstem (signals from both ears meet here), inferior colliculus (mid-brain) and medial geniculate nucleus
The coffee in this instance is our odor object (the source of the odor), and our olfactory mucosa and bulb (roof of nose) accepts odorant molecules carried into the nose by the air. Odorant molecules pass over the mucosa and come into contact with olfactory receptor neurons (ORNs) sensitive to specific odorant types. Each contains an olfactory receptor, similar to the retinal photoreceptors in the visual pathway. The olfactory receptor activates and sends a signal from the ORN to the glomeruli in the olfactory bulb, which receives sensory input, matches it to and fires for a particular odorant association. Odors leave the olfactory bulb after being mapped to the glomeruli and head to the piriform cortex, the main site for olfaction, where associations are made from learning. Chemotopic activation in the olfactory bulb and subsequently scattered ORN activation results in a pattern of neural activation in the piriform cortex across various cortices, from which we establish representations of odor for recognition, linking this pattern of activation with the associated odorant. Secondary olfactory processing is also done in the orbitofrontal cortex