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Appendix D: Glossary and Acronym List

Glossary

Term Definition
afferent

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

 

aphasia

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

 

apraxia of speech

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

 

assistive technologies

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

 

auditory nerve

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

 

auditory system

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

 

autism spectrum disorders

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

 

biofilm

communities of bacteria, such as the potentially antibiotic-resistant bacterial communities that are present in the middle ears of most children with chronic ear infections

 

biomarker

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

 

chemesthesis

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

 

chemical senses

taste and smell

 

cochlea

the organ of hearing

 

cochlear implant

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

 

comorbid

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

 

efferent

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

 

embryonic stem cells

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

 

epidemiology

the branch of medical science that investigates all the factors that determine the presence or absence of diseases and disorders in a population

 

epigenetics

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

 

eustachian tube

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

 

gene expression

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

 

genetics

the study of particular genes, DNA, and heredity

 

genomics

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

 

hair cells

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

 

hearing aid

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

 

idiopathic

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

 

inner ear

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

 

knockout

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, which helps determine its the function

 

larynx

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

 

model organism

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

 

mutation

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

 

neural prostheses

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

 

nociceptors

the relatively unspecialized nerve cell endings that initiate the sensation of pain

 

olfaction 

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

 

otitis media

inflammation of the middle ear caused by infection

 

ototoxic

a drug or compound such as a special class of antibiotics, aminoglycoside antibiotics, that can damage the hearing and balance organs located in the inner ear for some individuals

 

pathogenesis

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

 

phenotype

an individual’s physical and behavioral characteristics

 

pheromone

chemical substance secreted by an animal that elicits a specific behavioral or physiological response in another animal of the same species

 

polymorphism

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

 

psychoacoustics

the study of sound perception

 

rhinitis

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)

 

sinusitis

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

 

spasmodic dysphonia

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

 

spiral ganglion

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

 

stereocilia

see “hair cells”

 

stria vascularis

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

 

stuttering

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

 

synapse

a junction between two nerve cells

 

tinnitus

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

 

tonotopic

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

 

transduction

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

 

vertigo

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)

 

vestibular system system in the body that is responsible for maintaining balance, posture, and the body’s orientation in space; this system also regulates locomotion and other movements and keeps objects in visual focus as the body moves

 

Acronymn List

Acronymn Definition
ACC Autism Coordinating Committee
ARRA American Recovery and Reinvestment Act
ASD Autism Spectrum Disorder
DEA Division of Extramural Activities
DIR Division of Intramural Research
DNA Deoxyribonucleic Acid
DSP Division of Scientific Programs
EHDI Early Hearing Detection and Intervention
FY Fiscal Year
HHS Department of Health and Human Services
HPP High Program Priority
IACC Interagency Autism Coordinating Committee
ICOs Institutes, Centers, and Offices
M.D. Doctor of Medicine
NDCD National Deafness and Other Communication Disorders
NF2 Neurofibromatosis 2
NICHD Eunice Kennedy Shriver National Institute of Child Health and Human Development
NIDCD National Institute on Deafness and Other Communication Disorders
NIH National Institutes of Health
Ph.D. Doctor of Philosophy
Plan NIDCD Strategic Plan
SLI Specific Language Impairment
SPPB Science Policy and Planning Branch
T2R Type 2 Taste Receptors

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Last Updated Date: 
January 27, 2017