Question 1

Receptors for hearing are located in the ________.

Accepted Answer

Receptors for hearing are located in the cochlea, which is a spiral-shaped structure in the inner ear. The tympanic membrane, vestibule, and semicircular canals are all structures involved in balance and/or detecting motion, but not specifically for hearing.

Question 2

If you shine a light into one eye both pupils will constrict. The best explanation for this is________.

Accepted Answer

Sensory input from the retinas of both eyes converges at the optic chiasm and information from each eye is delivered to both the left and right sides of the brain. This is why shining a light into one eye will cause both pupils to constrict.

Question 3

Overlap in the visual fields of our eyes ________.

Accepted Answer

Overlap in the visual fields of our eyes allows us to subconsciously estimate the distance of objects based on the different angles the image strikes our two retinas. This is called binocular vision and is important for depth perception.

Question 4

Which of the follow types of neurons are replaced throughout adult life?

Accepted Answer

Olfactory receptor cells are the only type of neurons that are continuously generated throughout adult life, as they have the ability to regenerate every 30-60 days. The other options listed do not undergo significant replacement in adult life.

Question 5

Bitter taste is elicited by ________.

Accepted Answer

Bitter taste is primarily elicited by alkaloids, which are naturally occurring compounds often found in plants.

Question 6

Tom is a 45-year-old male that has lost his ability to hear high frequency sounds. The most likely explanation for this would be ________.

Accepted Answer

Damage to the hair cells near the oval window in the cochlear duct is the most likely cause of losing the ability to hear high frequency sounds, as these hair cells are responsible for detecting high frequency sounds.

Question 7

Select the statement below that is not true with regards to the process of light a daptation.

Accepted Answer

Visual acuity actually improves during light adaptation as the eye adjusts to high levels of illumination, allowing for better detail recognition and color perception.

Question 8

Flavor preferences, our likes and dislikes are said to have a "homeostatic value". Which of the following is the best example of this homeostatic value for taste preferences?

Accepted Answer

The presence of bitter taste receptors may warn us of potential toxicity, allowing us to avoid consuming harmful substances. Therefore, our preference for bitter tastes has a homeostatic value as it ensures our safety by avoiding potentially dangerous foods.

Question 9

What structure regulates the amount of light passing to the visual receptors of the eye?

Accepted Answer

The iris controls the size of the pupil, which regulates the amount of light passing through to the visual receptors of the eye.

Question 10

Photoreceptors are modified neurons. However, they differ from most neurons in the fact that________.

Accepted Answer

Photoreceptors differ from most neurons in the fact that they will hyperpolarize when stimulated, while most neurons will depolarize. This is due to the fact that photoreceptors are specialized to detect changes in light and need to be able to signal this information to the brain in a specific way. They also release neurotransmitters, so option B is incorrect. Option A is partially correct, as photoreceptors are sensitive to changes in light energy, but this alone does not fully differentiate them from other neurons. Option C is incorrect, as photoreceptors do have fluctuations in membrane potential, but those fluctuations are different from those of other neurons.

Question 11

Dancers will use a technique called "spotting" when they perform spins of the body. Byholding their head and eyes on a fixed point in front of them as their body spins they reduce the amount of head spinning and this prevents dizziness. Which of the following is the most likely explanation for why this works?

Accepted Answer

The answer of Dancers will use a technique called "spotting"...

Question 12

What is the main function of the rods in the eye?

Accepted Answer

The main function of the rods in the eye is vision in dim light. Rod cells are responsible for visual perception in conditions of low light intensity, such as during nighttime or in dark environments. They contain a pigment called rhodopsin, which is more sensitive to light than the pigment in cone cells, which are responsible for color vision and high-acuity vision. Therefore, rod cells enable us to see shapes and movements in low light conditions.

Question 13

The sensation of loudness or the volume of a sound is detected by ________.

Accepted Answer

Greater movement of the basilar membrane results in greater deflection of the hair cells, which is interpreted by the brain as increased loudness or volume of sound.

Question 14

Labyrinthitis is a medical condition often caused by viral infection, resulting in swelling and inflammation of the membranous labyrinth. Which of the following symptoms would you most associate with the condition of labyrinthitis?

Accepted Answer

Labyrinthitis affects the inner ear, which is responsible for balance and spatial orientation, leading to symptoms like loss of balance and dizziness.

Question 15

The receptor for static equilibrium is the ________.

Accepted Answer

The macula is the receptor for static equilibrium. It is located in the utricle and saccule of the inner ear. The macula is a small, round patch of sensory cells that are covered by a gelatinous membrane. The membrane is studded with tiny crystals of calcium carbonate, called otoconia. When the head is tilted, the otoconia move and stimulate the sensory cells, which send signals to the brain. The brain uses these signals to determine the position of the head and to maintain balance.

Question 16

Humans can smell as many as 10,000 different odors but have significantly fewer types of olfactory receptors. Which of the following is the best explanation for why humans candistinguish so many smells?

Accepted Answer

The sensation of a single, distinct smell is a combination of a variety of chemicals that stimulate different combinations of olfactory receptor cells all at once.

Question 17

Color vision has much greater resolution than night vision (vision that is mostly in shades of gray). Which of the following is the best explanation for why this is so?

Accepted Answer

A single cone photoreceptor often connects to a single bipolar cell and a single ganglion cell, allowing for high-resolution color vision, while the convergence of many rods onto a single ganglion cell results in lower-resolution night vision.

Question 18

A patient has a loss of hearing in only one ear. Which of the following is likely to be a result?

Accepted Answer

Localization of sound requires input from both ears, so a person with unilateral hearing loss will have difficulty determining where a sound is coming from.

Question 19

The elasticity of the lens decreases with age. This leads to which of the following?

Accepted Answer

As the elasticity of the lens decreases with age, it becomes more difficult for the lens to adjust its shape to focus on nearby objects. This results in less accommodation of the lenses, leading to difficulty focusing on nearby objects.

Question 20

Humans can see several thousand shades of color but have cone photoreceptors that aresensitive to only three (perhaps four) wavelengths of light. What is the best explanation for why we see so many colors?

Accepted Answer

Color perception is achieved by activation of various combinations between the three cone types. This is called trichromatic color vision and it allows us to perceive a wide range of colors by combining the signals from our red, green, and blue cones in different proportions. Additionally, our brains also take into account other visual cues such as brightness and contrast to enhance our perception of color.

Quiz 13: The Peripheral Nervous System and Reflex Activity