Adrenergic, sometimes spelled with an "l" as in adrenalnergic, refers to a type of neuron that releases adrenaline or a related hormone. The proper spelling is "adrenergic" with only one "l". This can be seen in the International Phonetic Alphabet (IPA) transcription: /ˌæd.rə.ˈnɜː.dʒɪk/. The "l" in adrenal no longer appears in the medical term despite its previous derivation from the adrenal gland, an endocrine organ that secretes adrenaline, noradrenaline, and other hormones.
Adrenergic refers to any substance, process, or effect that is related to or involves the action of epinephrine (also known as adrenaline) or norepinephrine (noradrenaline), hormones released by the adrenal glands. These hormones are part of the sympathetic nervous system and play a crucial role in the body's fight or flight response, which prepares an individual to handle stressful or dangerous situations.
Adrenergic substances refer to drugs or chemical compounds that mimic or enhance the actions of epinephrine and norepinephrine, either by directly binding to the same receptors or by increasing their release. These substances can have various effects on the body, such as increasing heart rate, constricting blood vessels, dilating airways, and increasing blood pressure. The adrenergic system influences multiple bodily functions, including cardiovascular function, respiratory function, metabolism, and regulation of stress responses.
Adrenergic receptors are specialized protein molecules located on the surface of various cells throughout the body, particularly in organs and tissues targeted by the sympathetic nervous system. There are two main types of adrenergic receptors - alpha-adrenergic receptors and beta-adrenergic receptors. Each type can be further divided into subtypes. These receptors mediate the physiological responses to epinephrine and norepinephrine by binding to them, initiating a cascade of events within the cell that ultimately leads to the desired effect.
Overall, the term "adrenergic" encompasses the hormones, receptors, and substances involved in the sympathetic nervous system's regulation of vital bodily functions and stress responses.
The word "adrenergic" is derived from the combination of two terms: "adrenal" and "erg".
- "Adrenal" refers to the adrenal glands, which are small triangular-shaped glands located on top of the kidneys. These glands play a crucial role in secreting various hormones, including adrenaline (also known as epinephrine).
- "Erg" is a combining form derived from the Greek word "ergon", meaning work or action.
Therefore, "adrenergic" literally translates to "related to adrenaline action or function". It is used to describe substances or processes that are influenced by or affect the actions of adrenaline or similar compounds.