FLEXOR (L. _flecto_, to bend). A muscle which bends the part into which it is inserted. Its antagonist is termed _extensor_. FLUIDS. Substances which have the quality of fluidity, and are, in consequence, of no fixed shape. FOLLICLE (L. dim. of _follis_, a pair of bellows). Literally, a little bag or scrip of leather. In anatomy, a very minute secreting cavity. FORAMEN (L. _foro_, to pierce). An opening. FOSSA (L. _fodio_, to dig). A ditch or trench; a little depression, or sinus. FUNCTION (L. _fungor_, to discharge an office). The office of an organ in the animal or vegetable economy; as of the heart in circulation, of the leaf in respiration, &c. G GALL-BLADDER. A membranous reservoir, lodged in a fissure on the under surface of the right lobe of the liver, and containing the bile. GALL-DUCTS. These are the _cystic_, proceeding from the gall-bladder; the _hepatic_, proceeding from the liver; and the _ductus communis choledochus_, resulting from the union of the two preceding. GANGLION (Gr. _gangglíon_, a nerve-knot). A small nervous center, or an enlargement in the course of a nerve, sometimes termed a _diminutive brain_. GASTER. The Greek term for stomach. GASTRIC (Gr. _gaster_, the stomach). Pertaining to the stomach; as the gastric juice, &c. GASTRIC JUICE. The peculiar digestive fluid secreted by the stomach. GELATINE (L. _gelu_, frost). The principle of jelly. It is found in the skin, cartilages, tendons, membranes and bones. The purest variety of gelatine is _isinglass_. GLAND (L. _glans_, _glandis_, an acorn). A soft body, composed of various tissues, vessels, nerves, &c., usually destined to separate some fluids from the blood. GLENOID (Gr. _glēne_, a cavity, _eīdos_, likeness). The name of a part having a shallow cavity; as the socket of the shoulder joint. GLOBULES RED (L. dim. of _globus_, a ball). The red coloring matter of the blood; a peculiar animal principle. GLOSSA, or GLOTTA (Gr. _glōtta_). The tongue; the organ of speech. _Glosso._ Terms compounded of this word belong to nerves or muscles attached to the tongue. GLOTTIS. The aperture of the larynx between the arytænoïd cartilages. It is covered by a cartilage called the _epi-glottis_. GRANULE. A small particle. H HÆMATOSIN (Gr. _haima_, blood). A characteristic constituent of the blood, derived from the globules. HÆMORRHAGE. A rupture of a blood-vessel; a bursting forth of blood; loss of blood. HEPATIC. A term applied to any part belonging to the liver. HUMERUS. The bone of the upper arm. HUMOR (L. _humeo_, to be moist). An aqueous substance; as the humors of the eye. HYGIENE (Gr. to be well). Health; the preservation of health; that part of medicine which regards the preservation of health. HYOIDES (the Greek letter _upsilon_). A bone situated between the root of the tongue and the larynx.