Glossary: Anxiety Disorder

Content provided by the Faculty of the Harvard Medical School

Glossary

adrenal glands: Two glands on top of the kidneys that secrete the hormones cortisol and norepinephrine.

agoraphobia: Fear and avoidance of open spaces and public spaces.

amygdala: A region of the brain that processes emotionally charged memories, including fear.

autonomic nervous system: The set of nerve pathways, starting with the hypothalamus in the brain, that controls vital functions like heart rate, body temperature, and blood pressure. It includes the sympathetic and parasympathetic nervous systems.

axon: The part of a neuron that carries impulses and stores neurotransmitters that convey signals to other neurons.

benzodiazepines: Medications that work by attaching to benzodiazepine-GABA receptors, helping to maintain levels of the neurotransmitter GABA in the brain.

brain imaging: A variety of technologies, such as magnetic resonance imaging (MRI), functional MRI (fMRI), and positron emission tomography (PET), used to examine the structure or function of the brain.

cognitive behavioral therapy: A form of therapy designed to correct ingrained patterns of negative thoughts or behaviors.

corticotropin-releasing factor (CRF): A hormone secreted by the hypothalamus that helps rouse the body to defend against a physical or emotional threat.

cortisol: A glucocorticoid, or steroid hormone, released by the adrenal glands. It helps trigger the "fight-or-flight" response and similar responses.

dendrites: The parts of a neuron that receive signals sent via neurotransmitters from other neurons.

gamma-aminobutyric acid (GABA): Chief inhibitory neurotransmitter in the brain. As an inhibitory neurotransmitter, it instructs the next neuron not to fire. GABA may help quell anxiety.

hippocampus: Part of the brain that plays a central role in processing long-term memories. It is smaller than normal in some people with post-traumatic stress disorder.

hypothalamic-pituitary-adrenal (HPA) axis: A system that governs a multitude of hormonal activities, including the body's response to stress.

hypothalamus: Part of the brain that regulates vital body functions (such as blood pressure and temperature). It receives signals from the body and secretes hormones that influence the production of other hormones.

limbic system: A group of brain structures associated with emotions, such as anger, pleasure, sorrow, fear, and sexual arousal.

locus ceruleus: An area of the brainstem that helps determine which stimuli are worth paying attention to. A malfunction of the locus ceruleus may contribute to anxiety.

neuron: A nerve cell.

neurotransmitters: Chemicals such as serotonin or norepinephrine that convey messages across the gap, or synapse, between adjoining neurons.

norepinephrine: A neurotransmitter that plays a role in the regulation of anxiety, mood, and responses to stress. Sometimes called noradrenaline.

pituitary gland: An endocrine gland tucked into a bony space beneath the brain. It receives input and influence from the hypothalamus. It produces adrenocorticotropic hormone (ACTH), which controls the secretion of cortisol by the adrenal glands. This helps trigger the "fight-or-flight" response.

selective serotonin reuptake inhibitors (SSRIs): Antidepressants that block the reabsorption of serotonin by the neurons that release it, leaving more serotonin available to nerve cell receptors.

serotonin: A neurotransmitter involved in regulating moods, sleep, and appetite, and inhibiting pain.

synapse: A tiny gap between neurons that neurotransmitters cross in conveying nerve impulses.

Last updated:	September 05, 2008