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English Dictionary of Medical Terms (02)

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No:20 - activate

1.to render activity. 2.to become active. 3.to convert (a compound, as a provitamin or enzyme) into an active form or different compound, esp. into one that has a particular biological action (e.g. ergosterol by irradiation to vitamin D2 for use in treating rickets).

No:21 - active

characterized by action; not passive; not expectant.

No:22 - activity

1. the state of being active; the ability to produce some effect; the extent of some function or action. 2. a thermodynamic quantity that represents the effective concentration of a solute in a nonideal solution; if concentrations are replaced by activities, the equations for equilibrium constants, electrode potentials, osmotic pressure, boiling point elevation, freezing point depression, and vapour pressures of volatile solutes are converted from approximations that hold only for dilute solutions to exact equations that hold for all concentrations. The activity is equal to the product of the concentration and the activity coefficient, a dimensionless number measuring deviation from nonideality. Symbol a. 3. radioactivity; the number of disintegrations per unit time of a radioactive material, measured in curies or becquerels. Symbol A. 4. optical activity.

No:23 - acuity

(L. acuitas sharpness) clarity or clearness, especially of the vision.

No:24 - acute

(L. acutus sharp) 1. sharp, poignant. 2. having a short and relatively severe course.

No:25 - adaptation

(L. adaptare to fit) 1. the adjustment of an organism to its environment, or the process by which it enhances such fitness. 2. the normal ability of the eye to adjust itself to variations in the intensity of light; the adjustment to such variations. 3. the decline in the frequency of firing of a neuron, particularly of a receptor, under conditions of constant stimulation. 4. in dentistry, (a) the proper fitting of a denture, (b) the degree of proximity and interlocking of restorative material to a tooth preparation, (c) the exact adjustment of bands to teeth. 5. in microbiology, the adjustment of bacterial physiology to a new environment.

No:26 - addiction

the state of being given up to some habit, especially strong dependence on a drug.

No:27 - additional

existing or coming by way of addition; added, further.

No:28 - additive

1. characterized by addition. 2. a substance, as a flavouring agent, preservative, or vitamin, added to another substance to improve its appearance, increase its nutritional value, etc.

No:29 - adenitis

inflammation of a gland.

No:30 - adenoma

(adeno- + -oma) a benign epithelial tumour in which the cells form recognizable glandular structures or in which the cells are clearly derived from glandular epithelium.

No:31 - adequate

satisfactory in quantity or quality; sufficient.

No:32 - adhesion

(L. adhaesio, from adhaerere to stick to) 1. the property of remaining in close proximity, as that resulting from the physical attraction of molecules to a substance, or the molecular attraction existing between the surfaces of contacting bodies. 2. the stable joining of parts to each other, which may occur abnormally. 3. a fibrous band or structure by which parts abnormally adhere.

No:33 - adjuvant

(L. adjuvans aiding) a substance which aids another, such as an auxiliary remedy; in immunology, nonspecific stimulator (e.g., BCG vaccine) of the immune response.

No:34 - adnexitis

inflammation of the adnexa uteri.

No:35 - adolescent

an individual during the period of adolescence.

No:36 - adrenergic

activated by, characteristic of, or secreting epinephrine or substances with similar activity; the term is applied to those nerve fibres that liberate norepinephrine at a synapse when a nerve impulse passes, i.e., the sympathetic fibres.

No:37 - adrenolytic

(adreno + Gr. lysis a loosening) inhibiting the action of adrenergic nerves; inhibiting the response to epinephrine.

No:38 - adsorption

(L. ad to + sorbere to suck) the attachment of one substance to the surface of another; the concentration of a gas or a substance in solution in a liquid on a surface in contact with the gas or liquid, resulting in a relatively high concentration of the gas or solution at the surface. Cf. absorption.

No:39 - adult

(L. adultus grown up) a living organism which has attained full growth or maturity.

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