colloid

colloid
1. Aggregates of atoms or molecules in a finely divided state (submicroscopic), dispersed in a gaseous, liquid, or solid medium, and resisting sedimentation, diffusion, and filtration, thus differing from precipitates. SEE ALSO: hydrocolloid. 2. Gluelike. 3. A translucent, yellowish, homogeneous material of the consistency of glue, less fluid than mucoid or mucinoid, found in the cells and tissues in a state of c. degeneration. SYN: colloidin. 4. The stored secretion within follicles of the thyroid gland. For individual colloids not listed below, see the specific name. [G. kolla, glue, + eidos, appearance]
- bovine c. SYN: conglutinin.
- emulsion c. SYN: emulsoid.
- hydrophil c., hydrophilic c. SYN: emulsoid.
- irreversible c. a c. that is not again soluble in water after having been dried at ordinary temperature. SYN: unstable c..
- lyophilic c. SYN: emulsoid.
- protective c. a c. that has the power of preventing the precipitation of suspensoids under the influence of an electrolyte.
- c. pseudomilium SYN: c. milium.
- reversible c. a c. that is again soluble in water after having been dried at ordinary temperature. SYN: stable c..
- stable c. SYN: reversible c..
- styptic c. SYN: styptic collodion.
- thyroid c. the semifluid material that occupies the lumen of thyroid follicles; it mainly contains thyroglobulin.
- unstable c. SYN: irreversible c..

* * *

col·loid 'käl-.ȯid n
1) a gelatinous or mucinous substance found in tissues in disease or normally (as in the thyroid)
2 a) a substance consisting of particles that are dispersed throughout another substance and are too small for resolution with an ordinary light microscope but are incapable of passing through a semipermeable membrane
b) a mixture (as smoke) consisting of a colloid together with the medium in which it is dispersed
col·loi·dal kə-'lȯid-əl, kä- adj
col·loi·dal·ly -əl-ē adv

* * *

col·loid (kolґoid) [Gr. kollōdēs glutinous] 1. glutinous or resembling glue. 2. a substance comprising very small, insoluble particles, usually 1 to 1000 nm in diameter, that are uniformly dispersed or suspended in a finely divided state throughout a continuous dispersion medium, not settling readily; the phase may be solid, liquid, or gas. The particles are often called the dispersed phase and the dispersion medium the continuous phase. Colloid can refer specifically to the particles or to the system of particles plus dispersion medium. 3. thyroid c. colloidal adj

Medical dictionary. 2011.

Игры ⚽ Поможем сделать НИР

Look at other dictionaries:

  • Colloid — Col loid, n. 1. (Physiol. Chem.) A substance (as albumin, gum, gelatin, etc.) which is of a gelatinous rather than a crystalline nature, and which diffuses itself through animal membranes or vegetable parchment more slowly than crystalloids do;… …   The Collaborative International Dictionary of English

  • Colloid — Col loid, a. [Gr. ko lla glue + oid. Cf. {Collodion}.] Resembling glue or jelly; characterized by a jellylike appearance; gelatinous; as, colloid tumors. [1913 Webster] …   The Collaborative International Dictionary of English

  • colloid — [käl′oid΄] n. [< Gr kolla, glue + OID; coined by T. Graham (1805 69), Scot chemist] 1. a) a solid, liquid, or gaseous substance made up of very small, insoluble particles (as single large molecules or masses of smaller molecules) that remain… …   English World dictionary

  • colloid — 1847, from Fr. colloide (1845), from Gk. kolla glue + oeides form (see OID (Cf. oid)) …   Etymology dictionary

  • colloid — ► NOUN 1) a homogeneous substance consisting of submicroscopic particles of one substance dispersed in another, as in an emulsion or gel. 2) a gelatinous substance. DERIVATIVES colloidal adjective. ORIGIN from Greek kolla glue …   English terms dictionary

  • Colloid — Milk is an emulsified colloid of liquid butterfat globules dispersed within a water based solution. A colloid is a substance microscopically dispersed evenly throughout another substance.[1] A colloidal system consists of two separate phases: a… …   Wikipedia

  • colloid — noun Etymology: International Scientific Vocabulary coll + oid Date: circa 1852 1. a gelatinous or mucinous substance found normally in the thyroid and also in diseased tissue 2. a. a substance that consists of particles dispersed …   New Collegiate Dictionary

  • colloid — /kol oyd/, n. 1. Physical Chem. a substance made up of a system of particles with linear dimensions in the range of about 10 7 to 5 × 10 5 cm dispersed in a continuous gaseous, liquid, or solid medium whose properties depend on the large specific …   Universalium

  • colloid — 1. adjective /ˈkɒlɔɪd/ Glue like. 2. noun /ˈkɒlɔɪd/ a) A stable system of two phases, one of which is dispersed in the other in the form of very small droplets or particles. b) An intimate mixture of two substances one of which, called the… …   Wiktionary

  • colloid — koloidinė sistema statusas T sritis chemija apibrėžtis Heterogeninė sistema, kurios dispersinės fazės dalelių matmenys 10⁻⁹–10⁻⁷ m. atitikmenys: angl. colloid; colloidal system rus. коллоид; коллоидная система ryšiai: sinonimas – koloidas …   Chemijos terminų aiškinamasis žodynas

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”