Sensorineural hearing loss is permanent and often results from the loss or damage to hair cells or the nerve from the ear to the brain. For this reason, it occurs from damage to the inner ear, where the nerve and hair cells are located. Damage to the middle ear would result in conductive hearing loss. Damage to the outer ear, would likely result in decreased sound localization. 

Sound waves are pressure changes and loudness is related to the amplitude of the wave. It is quantified by the decibel (dB). Pascal is the standard unit for pressure. Whereas, Hertz is used to quantify frequencies and an octave is a doubling in frequency. Meters/second describes the speed at which sound propagates.

Addison's disease, a chronic disorder of the endocrine system, is caused by an inability of the adrenal glands to produce sufficient steroid hormones (specifically, two types of necessary natural corticosteroids). In addition to causing renal insufficiency and muscle weakness, Addison's has been known to idiopathically—through an unknown mechanism—hyper-sensitize one or more senses in the body, most commonly taste.

The receptors for salty and sour are believed to be ion sensors. MSG stimulates receptors corresponding to unami. PROP causes an intense bitter sensation in "supertasters." Sweet and bitter receptors are believed to be similar to odorant receptors because molecules dock on transmembrane receptors in order to initiate an action potential.

Assuming that a food critic or wine taster most values their ability to perceive the flavors and aromas of these consumable items, then a loss of their sense of smell—olfactory loss—would be the greatest of these misfortunes they could suffer. The vestibular sense is that which informs us as to the orientation of our bodies in space. The semicircular canals contribute to this sense, and are housed within the inner ears. The loss of this sense might not compromise a food critic or wine taster as severely in their professional life. The striate cortex is a key component of the visual cortex, and damage therein would likely result in partial or total blindness. This would not hinder the food critic or wine taster's abilities to perceive their foods or wines however.

There are about three hundred and fifty receptor types involved in olfaction. Each receptor responds to more than one molecule, but with different strengths. Receptors make their first synapse with glomeruli, but each glomerulus receives input from only one type of receptor.

The Moro reflex (also called the "startle reflex") generally lasts in newborns until the age of six months. When startled, a newborn exhibiting the Moro reflex will throw its head back and its arms and legs out simultaneously, cry, then pull its limbs back in.

The somatosensory system is a sense system based around information about the physical body. This includes the senses of touch, of heat, of pain, pressure, and vibration; of orientation and balance; and of muscular movement. The tactile and skin senses, the vestibular sense, and the kinesthetic sense comprise it. The tactile sense is that of touch. Other skin senses include detection of heat, pain, pressure, and vibration. The vestibular sense is that which detects the body's orientation in space, and contributes to our sense of balance and motion. The kinesthetic sense is based off the movements and positions of our muscles, and may also be referred to as proprioception. This sense is how we can close our eyes yet remain aware of where our limbs are positioned in space, or why we don't need to follow our legs and arms with our eyes to direct them while we walk or reach for objects out of view. The other answer choices do not involve correct groupings of senses to summarize the somatosensory system.

An action potential describes the event of an electrical impulse being activated by a given neuron once it is sufficiently polarized. We may think of an experience such as pain. If I prick my finger with a needle, I feel a small amount of pain. If, however, I unfortunately lose my fingertip due to a mechanical accident of some sort, I will feel much more pain. This difference in pain is not due to the strength of any one given action potential. An action potential either leads to an electrical impulse or it does not (in other words, it is all-or-none). There are no gradients in strength or degree; however, the number of action potentials occurring across neurons can have a cumulative effect (e.g., greater number of nerve cells involved in the more serious injury of losing a finger tip equates to a greater experience of pain).

While potassium—alongside sodium—plays a vital role in the functioning of neurons and in the exchange of neurotransmitters, it is not a neurotransmitter. Rather, it is involved in the shifting of polarity in the neuron that leads to an action potential. In other words, the amount of potassium present in a given neuron directly impacts meeting the threshold of an action potential. Serotonin, dopamine, and norepinephrine are neurotransmitters released by these action potentials.