Excretion (Lat. _excerno_, to separate). The separation from the blood of the waste matters of the body; also the materials excreted.

Exosmosis (Gr. ???, without, and ????, to push). The current from within _outwards_ when diffusion of fluids takes place through a membrane.

Expiration (Lat. _expiro_, to breathe out). The act of forcing air out of the lungs.

Extension (Lat. _ex_, out, and _tendo_, to stretch). The act of restoring a limb, etc., to its natural position after it has been flexed or bent; the opposite of _flexion_.

Fauces. The part of the mouth which opens into the pharynx.

Fenestra (Lat.). Literally, "a window." Fenestra ovalis and fenestra rotunda, the oval and the round window; two apertures in the bone between the tympanic cavity and the labyrinth of the ear.

Ferment. That which causes fermentation, as yeast.

Fermentation (Lat. _fermentum_, boiling). The process of undergoing an effervescent change, as by the action of yeast; in a wider sense, the change of organized substances into new compounds by the action of a ferment. It differs in kind according to the nature of the ferment.

Fiber (Lat. _fibra_, a filament). One of the tiny threads of which many parts of the body are composed.

Fibrilla. A little fiber; one of the longitudinal threads into which a striped muscular fiber can be divided.

Fibrin (Lat. _fibra_, a fiber). An alb.u.minoid substance contained in the flesh of animals, and also produced by the coagulation of blood.

Flexion (Lat. _flecto_, to bend). The act of bending a limb, etc.

Follicle (Lat. dim. of _follis_, a money bag). A little pouch or depression.

Fomentation (Lat. _foveo_, to keep warm). The application of any warm, medicinal substance to the body, by which the vessels are relaxed.

Foramen. A hole, or aperture.

Frontal Sinus. A blind or closed cavity in the bones of the skull just over the eyebrows.

Fumigation (Lat. _fumigo_, to perfume a place). The use of certain fumes to counteract contagious effluvia.

Function (Lat. _functio_, a doing). The special duty of any organ.

Ganglion (Gr. ???????, a knot). A knot-like swelling in a nerve; a smaller nerve center.

Gastric (Gr. ?ast??, stomach). Pertaining to the stomach.

Gelatine (Lat. _gelo_, to congeal). An animal substance which dissolves in hot water and forms a jelly on cooling.

Germ (Lat. _germen_, a sprout, bud). Disease germ; a name applied to certain tiny bacterial organisms which have been demonstrated to be the cause of disease.

Germicide (_Germ_, and Lat. _caedere_, to kill). Any agent which has a destructive action upon living germs, especially _bacteria_.

Gland (Lat. _glans_, an acorn). An organ consisting of follicles and ducts, with numerous blood-vessels interwoven.

Glottis (Gr. ???tta, the tongue).

The narrow opening between the vocal cords.

Glucose. A kind of sugar found in fruits, also known as grape sugar.

Gluten. The glutinous alb.u.minoid ingredient of cereals.

Glycogen. Literally, "producing glucose." Animal starch found in liver, which may be changed into glucose.

Gram. Unit of metric system, 15.43 grains troy.

Groin. The lower part of the abdomen, just above each thigh.

Gustatory (Lat. _gusto_, _gustatum_, to taste). Belonging to the sense of _taste_.

Gymnastics (Gr. ??????, to exercise). The practice of athletic exercises.

Haemoglobin (Gr. a?a, blood, and Lat. _globus_, a globe or globule).

A complex substance which forms the princ.i.p.al coloring const.i.tuent of the red corpuscles of the blood.

Hemispheres (Gr. ??, half, and sfa??a, a sphere). Half a sphere, the lateral halves of the cerebrum, or brain proper.

Hemorrhage (Gr. a?a, blood, and ??????, to burst). Bleeding, or the loss of blood.

Hepatic (Gr. ?pa?, the liver). Pertaining to the liver.

Herbivorous (Lat. _herba_, an herb, and _voro_, to devour). Applied to animals that subsist upon vegetable food.

Heredity. The predisposition or tendency derived from one's ancestors to definite physiological actions.

Hiccough. A convulsive motion of some of the muscles used in breathing, accompanied by a shutting of the glottis.

Hilum, sometimes written Hilus. A small fissure, notch, or depression. A term applied to the concave part of the kidney.

h.o.m.ogeneous (Gr. ???, the same, and ?????, kind). Of the _same kind_ or quality throughout; uniform in nature,--the reverse of heterogeneous.

Humor. The transparent contents of the eyeball.

Hyaline (Gr. ?a???, gla.s.s). Gla.s.s-like, resembling gla.s.s in transparency.

Hydrogen. An elementary gaseous substance, which, in combination with oxygen, produces water.

Hydrophobia (Gr. ?d??, water, and f???a?, to fear). A disease caused by the bite of a rabid dog or other animal.

Hygiene (Gr. ???e?a health). The art of preserving health and preventing disease.

Hyoid (Gr. letter ?, and e?d??, form, resemblance). The bone at the root of the tongue, shaped like the Greek letter ?.

Hypermetropia (Gr. ?p?? over, beyond, ?t???, measure, and ???, the eye). Far-sightedness.