Hearing and Chemical Senses Lecture Review

Flashcards covering key vocabulary terms related to hearing, chemical senses (smell and taste), skin sensations, and basic principles of perception, based on lecture notes.

Sound Stimulus

Waves of depression and refraction in some medium (e.g., air or water).

Amplitude (Sound)

The measure of energy in a sound wave, roughly equating to our perceptual experience of loudness.

Loudness

The perceptual experience corresponding to the amplitude of a sound wave.

Frequency (Sound)

The number of cycles in a particular period of time in a sound wave, roughly equating to pitch.

Pitch

The perceptual experience corresponding to the frequency of a sound wave; higher frequency means higher pitch, lower frequency means lower pitch.

Hertz (Hz)

The unit of measurement for frequency, representing cycles per second.

Decibels (dB)

The unit of measurement for amplitude.

Pinna

The oddly shaped structure sticking off the side of the head, which helps direct and capture sound energy for sound localization.

External Auditory Canal

The tube at the end of the pinna that leads into the skull, protecting delicate ear structures.

Tympanic Membrane

A membrane stretched across the end of the auditory canal (eardrum) that vibrates when hit by sound waves.

Middle Ear

An air-filled space on the other side of the tympanic membrane, containing the ossicles.

Ossicles

Three tiny bones in the middle ear: the malleus, incus, and stapes, which transmit vibrations from the tympanic membrane.

Malleus

The first ossicle, attached to the inside of the tympanic membrane; translates its vibrations.

Incus

The second ossicle, hinged with the malleus and stapes.

Stapes

The third ossicle, hinged with the incus and connected to the oval window of the inner ear.

Eustachian Tube

A tube that connects the middle ear to the sinuses, helping to equalize pressure.

Inner Ear

Composed of the cochlea, beginning at the oval window.

Cochlea

A snail-shell shaped bony structure in the inner ear containing three fluid-filled tunnels.

Oval Window

A membrane at the beginning of the inner ear that the stapes pushes on, causing fluid in the cochlea to vibrate.

Scala Tympani

The bottom tube within the cochlea where fluid vibrations wrap around.

Round Window

A pressure release valve at the far end of the scala tympani, preventing fluid from going back through the tubes.

Cochlear Canal

The middle section of the cochlea, which contains the organ of Corti.

Organ of Corti

A grouping of structures within the cochlear canal, including the tectorial and basilar membranes and hair cells, responsible for converting mechanical energy into neural signals.

Tectorial Membrane

A stiff and rigid membrane in the organ of Corti that does not move.

Basilar Membrane

A membrane in the organ of Corti that moves up and down in response to fluid waves, causing hair cells to flex.

Hair Cells

Sensory receptors lodged in the basilar membrane with projections called cilia, which generate neural signals when brushed against the tectorial membrane.

Cilia (Ear)

Fibers sticking out from hair cells; their bending opens ion channels, leading to neural signal generation.

Frequency Theory (Pitch Perception)

Theory stating that the basilar membrane and hair cells vibrate at the same frequency as the sound energy, explaining the perception of low-pitched sounds.

Place Theory (Pitch Perception)

Theory stating that different places on the basilar membrane resonate and bend significantly to specific pitches based on its thickness and width, explaining the perception of high-pitched sounds.

Conduction Deafness

Difficulty in conducting sound from the external world to the inner ear, often due to damage to the tympanic membrane or auditory ossicles.

Stimulation Deafness

Hearing loss caused by exposure to loud sounds, resulting in the shearing off of stereocilia from hair cells.

Tinnitus

Ringing in the ears, which can be a warning sign of cilia bending from loud sound exposure.

Hearing Aids

Devices that amplify sounds, particularly in the range of human speech, to assist with hearing loss.

Cochlear Implant

A device used for complete hearing loss that attempts to replicate the cochlea's function by generating nerve signals for the auditory nerve.

Chemical Senses

Smell (olfaction) and taste (gustation), which respond to chemicals and have specific receptors for them.

Olfaction

The sense of smell, which is our evolutionarily oldest sensory system, detecting volatile compounds in the air.

Pheromones

Odors released by other individuals of the same species that communicate information or directly control hormone responses.

Signaling Pheromone

Pheromones that convey information, such as territory boundaries or the presence of another animal.

Primary Pheromone

Pheromones that exert direct hormone control over the behavior of others of the same species (e.g., Bruce effect in mice, puberty suppression in naked mole rats).

Olfactory Bulb

A structure in the brain to which the olfactory nerve transmits signals, bypassing the thalamus, and tightly connected with the limbic system.

Gustation

The sense of taste, hypothetically made up of five different flavors, influenced by smell and pain.

Taste Receptors

Specialized receptors for basic flavors: sweet, bitter, sour, salty, and umami.

Umami

A fifth basic taste, often described as savory or brothy.

Supertasters

Individuals with a significantly higher number of taste receptors (up to 10,000).

Skin Sensations

Five types of sensations processed by the skin through different receptor types: light touch, pressure, hot, cold, and pain.

Visceral Pain

Pain that originates from internal organs.

Referred Pain

Pain that seems to originate from one location in the body but is actually occurring from someplace else.

Dynamic Touch

The experience of touch that includes not just sensations on the skin but also information from muscles, bones, and body movement through space.

Adaptation (Sensory)

The process where sensory receptors send a weaker and weaker signal to unchanging stimuli; occurs at the sensory receptor level.

Habituation

A reduced response to repeated stimuli that occurs at a higher cognitive level than sensory adaptation, allowing for selective focus.

Perception

The process of taking sensory information into the brain and making sense out of it.

Visual Cliff

An experimental apparatus with an apparent drop-off, used to demonstrate that babies can perceive depth by six months of age.

Size Constancy

A perceptual constancy where the perceived size of an object remains constant despite changes in its retinal image size as distance varies.

Shape Constancy

A perceptual constancy where the perceived shape of an object remains constant despite changes in its retinal image shape due to viewing angle variations.