Appendix D: Glossary and Acronym List

conducting toward the center; for neurons, conducting nerve impulses toward the spinal cord and brain

total or partial loss of the ability to use or understand language; usually caused by stroke, brain disease, or injury

a speech disorder, also known as verbal apraxia or dyspraxia, in which a person has trouble speaking because of inability to execute a voluntary movement despite normal muscle function

products, devices, or equipment that help maintain, increase, or improve the functional capabilities of people with disabilities

eighth cranial nerve that connects the inner ear to the brainstem and is responsible for hearing and balance

the outer, middle, and inner ear, along with the neurons and brain regions involved in hearing

a spectrum of developmental disorders that begin in early childhood and persists throughout adulthood; autism spectrum disorders affect three crucial areas of development: communication, social interaction, and creative or imaginative play

colonies of antibiotic-resistant bacteria that are present in the middle ears of most children with chronic ear infections

a specific physical trait or a measurable biologically produced change in the body connected with a disease or health condition

neural circuitry and brain regions involved in processing sound

the “feel” of a chemical; the term describes chemically provoked irritation

taste and smell; see “gustation” and “olfaction”

see “inner ear”

a medical device that bypasses damaged structures in the inner ear and directly stimulates the auditory nerve, allowing some people who are deaf or HoH to learn to hear and interpret sounds and speech

the existence of one or more co-occurring disorders in addition to a primary disorder

conducting away from the center; for neurons, conducting outward from the spinal cord and brain

cells that are derived from the inner cell mass of blastocyst stage embryos, are capable of dividing without differentiating for a prolonged period in culture, and are known to develop into cells and tissues of the three primary germ layers

the study of heritable changes caused by the activation and deactivation of genes without any change in the underlying DNA sequence of the organism

a small passageway that connects the upper part of the throat to the middle ear; its job is to supply fresh air to the middle ear, drain fluid, and keep air pressure at a steady level between the nose and the ear

the process by which the information encoded in a gene is used to direct the assembly of a protein molecule; different subsets of genes are expressed in different cell types or under different conditions

the study of particular genes, DNA, and heredity

the study of the genome (the entire genetic makeup) of an organism

tasting; the sensation produced by a stimulus applied to the gustatory nerve endings in the tongue

sensory cells of the inner ear, which are topped with hair-like structures (stereocilia) and which transform the mechanical energy of sound waves into nerve impulses

an electronic device that brings amplified sound to the ear; it usually consists of a microphone, amplifier, and receiver

relating to a disease or disorder that arises spontaneously or without a known cause

a type of pluripotent stem cell, similar to an embryonic stem cell, formed by the introduction of certain embryonic genes into a somatic cell

a sub-discipline of biology and computer science concerned with the acquisition, storage, analysis, and dissemination of biological data (most often DNA and amino acid sequences) to determine gene and protein functions, establish evolutionary relationships, and predict the three-dimensional shapes of proteins

part of the ear that contains both the organ of hearing (the cochlea) and the organ of balance (the labyrinth)

an organism that has been genetically engineered to lack one or more specific genes; scientists study knockout organisms to determine the impact of the missing gene(s) so as to understand the function of the missing gene(s)

valve structure between the trachea (windpipe) and the pharynx (the upper throat) that is the primary organ of voice production

inner ear disorder that can affect both hearing and balance and causes a sensation of fullness in the ear along with episodes of vertigo, hearing loss, and tinnitus

animal species used in medical research to mimic aspects of a disease found in humans

a change in a DNA sequence that can result from DNA copying mistakes made during cell division, exposure to ionizing radiation, exposure to chemical mutagens, or infection by viruses

devices such as the cochlear implant that substitute for an injured or diseased part of the nervous system

smell; to perceive odor or scent through stimuli affecting the olfactory nerves

inflammation of the middle ear caused by infection

the development of a disease or condition, particularly the cellular and molecular origins and causes of disease development

the components of the outer, middle, and inner ear involved in hearing

an individual’s physical and behavioral characteristics

one of two or more variants of a particular DNA sequence that can correlate with disease, drug response, and other phenotypes; the most common type of polymorphism involves variation at a single base pair (single nucleotide polymorphism) of DNA

the ability to sense the position, location, orientation, and movement of the body and its parts

the study of the relationship between physical stimulus and perception

inflammation of the mucous membranes of the nose, generally accompanied by discharge (runny nose) and usually caused by a virus infection (e.g., the common cold) or by an allergic reaction (e.g., hay fever)

inflammation or infection of one of the air-filled nasal sinuses

momentary disruption of voice caused by involuntary movements of one or more muscles of the larynx

the group of nerve cells that serve the sense of hearing by sending a representation of sound from the cochlea to the brain; the cell bodies of the spiral ganglion neurons are found in the spiral structure of the cochlea

see “hair cells”

specialized epithelium lining the cochlear duct that maintains the ion homeostasis of the fluid within the cochlea

a speech disorder in which sounds, syllables, or words are repeated or prolonged, disrupting the normal flow of speech

sensation of a ringing, roaring, or buzzing sound in the ears or head when no actual sound stimulus is present in the environment

the spatial arrangement of where sounds of different frequency are processed in the brain. For example – the auditory nerves that carry signals from adjacent portions of the cochlea project their information to adjacent portions of the auditory cortex

the process by which stimuli in the environment are converted into electrical (neural) signals by sensory receptors

having one or more DNA sequences from another species introduced by artificial means

illusion of movement; a sensation as if the external world were revolving around an individual (objective vertigo) or as if the individual were revolving in space (subjective vertigo)