Abdomen (Lat. abdo, abdere, to conceal). The largest cavity of the body, containing the liver, stomach, intestines, and other organs.

Abductor (Lat. abduco, to draw from). A muscle which draws a limb from the middle line of the body, or a finger or toe from the middle line of the foot or hand.

Absorbents (Lat. absorbere, to suck up). The vessels which take part in the process of absorption.

Absorption. The process of sucking up nutritive or waste matters by the blood-vessels or lymphatics.

Accommodation of the Eye. The alteration in the shape of the crystalline lens, which accommodates, or adjusts, the eye for near or remote vision.

Acetabulum (Lat. acetabulum, a small vinegar-cup). The cup-shaped cavity of the innominate bone for receiving the head of the femur.

Acid (Lat. acidus, from acere, to be sour). A substance usually sour, sharp, or biting to the taste.

Acromion (Gr. ἀκρον the tip, and ᾧμος, the shoulder). The part of the scapula forming the tip of the shoulder.

Adam’s Apple. An angular projection of cartilage in the front of the neck. It may be particularly prominent in men.

Adductor (Lat. adduco, to draw to). A muscle which draws towards the middle line of the body, or of the hand or foot.

Adenoid (Gr. ἀδήν, a gland). Tissue resembling gland tissue.

Afferent (Lat. ad, to, and fero, to convey). Vessels or nerves carrying the contents or impulses from the periphery to the center.

Albumen, or Albumin (Lat. albus, white). An animal substance resembling the white of an egg.

Albuminuria. A combination of the words “albumin” and “urine.” Presence of albumen in the urine.

Aliment (Lat. alo, to nourish). That which affords nourishment; food.

Alimentary (Lat. alimentum, food). Pertaining to aliment, or food.

Alimentary Canal (Lat. alimentum). The tube in which the food is digested or prepared for reception into the blood.

Alkali (Arabic al kali, the soda plant). A name given to certain substances, such as soda, potash, and the like, which have the power of combining with acids.

Alveolar (Lat. alveolus, a little hollow). Pertaining to the alveoli, the cavities for the reception of the teeth.

Amoeba (Gr. ἀμείβω, to change). A single-celled, protoplasmic organism, which is constantly changing its form by protrusions and withdrawals of its substance.

Amoeboid. Like an amoeba.

Ampulla (Lat. ampulla, a wine-flask). The dilated part of the semicircular canals of the internal ear.

Anabolism (Gr. ἀναβάλλω, to throw or build up). The process by means of which simpler elements are built up into more complex.

AnÆsthetics (Gr. ἀν, without, and αἰσθησία, feeling). Those medicinal agents which prevent the feeling of pain, such as chloroform, ether, laughing-gas, etc.

Anastomosis (Gr. ἀνά, by, and στόμα, a mouth). The intercommunication of vessels.

Anatomy (Gr. ἀνατέμνω, to cut up). The science which describes the structure of living things. The word literally means dissection.

Antiseptic (Lat. anti, against, and sepsis, poison). Opposing or counter-acting putrefaction.

Antrum (Lat. antrum, a cave). The cavity in the upper jaw.

Aorta (Gr. ἀορτή, from ἀείρο, to raise up). The great artery that rises up from the left ventricle of the heart.

Aponeurosis (Gr. ἀπό, from, and νεῦρον, a nerve). A fibrous membranous expansion of a tendon; the nerves and tendons were formerly thought to be identical structures, both appearing as white cords.

Apoplexy (Gr. ἀποπληξία, a sudden stroke). The escape of blood from a ruptured blood-vessel into the substance of the brain.

Apparatus. A number of organs of various sizes and structures working together for some special object.

Appendages (Lat. ad and pendeo, to hang from). Something connected with a part.

Aqueous Humor (Lat. aqua, water). The watery fluid occupying the space between the cornea and crystalline lens of the eye.

Arachnoid Membrane (Gr. ἀράχνη, a spider, and εἰδώς, like). The thin covering of the brain and spinal cord, between the dura mater and the pia mater.

Arbor VitÆ. Literally, “the tree of life”; a name given to the peculiar appearance presented by a section of the cerebellum.

Areolar (Lat. areola, a small space, dim. of area). A term applied to a connective tissue containing small spaces.

Artery (Gr. ἀήρ, air, and τερέω, to contain). A vessel by which blood is carried away from the heart. It was supposed by the ancients to contain only air, hence the name.

Articulation (Lat. articulo, to form a joint). The more or less movable union of bones, etc.; a joint.

Arytenoid Cartilages (Gr. ἀρύταινα, a ladle). Two small cartilages of the larynx, resembling the mouth of a pitcher.

Asphyxia (Gr. ἀ, without, and σφίξις, the pulse). Literally, “without pulse.” Condition caused by non-oxygenation of the blood.

Assimilation (Lat. ad, to, and similis, like). The conversion of food into living tissue.

Asthma (Gr. ἆσθμα, a gasping). Spasmodic affection of the bronchial tubes in which free respiration is interfered with, owing to their diminished caliber.

Astigmatism (Gr. ἀ, without, and στίγμα, a point). Irregular refraction of the eye, producing a blurred image.

Atrophy (Gr. ἀ, without, and τροφή, nourishment). Wasting of a part from lack of nutrition.

Auditory Nerve (Lat. audio, to hear). The special nerve of hearing.

Auricle (Lat. auricula, a little ear). A cavity of the heart.

Azygos (Gr. ἀ, without, and ζυγός, a yoke). Without fellow; not paired.

Bacteria (βακτήριον, a staff). A microscopic, vegetable organism; certain species are active agents in fermentation, while others appear to be the cause of infectious diseases.

Bactericide (Bacterium and Lat. caedere, to kill). Same as germicide.

Bile. The gall, or peculiar secretion of the liver; a viscid, yellowish fluid, and very bitter to the taste.

Biology (Gr. βίος, life, and λόγος, discourse). The science which treats of living bodies.

Bladder (Saxon bleddra, a bladder, a goblet). A bag, or sac, serving as a receptacle of some secreted fluid, as the gall bladder, etc. The receptacle of the urine in man and other animals.

Bright’s Disease. A group of diseases of the kidney, first described by Dr. Bright, an English physician.

Bronchi (Gr. βρόγχος, windpipe). The first two divisions, or branches, of the trachea; one enters each lung.

Bronchial Tubes. The smaller branches of the trachea within the substance of the lungs terminating in the air cells.

Bronchitis. Inflammation of the larger bronchial tubes; a “cold” affecting the air passages.

Bunion. An enlargement and inflammation of the first joint of the great toe.

Bursa. A pouch; a membranous sac interposed between parts which are subject to movement, one on the other, to allow them to glide smoothly.

Callus (Lat. calleo, to be thick-skinned). Any excessive hardness of the skin caused by friction or pressure.

Canal (Lat. canalis, a canal). A tube or passage.

Capillary (Lat. capillus, hair). The smallest blood-vessels, so called because they are so minute.

Capsule (Lat. capsula, a little chest). A membranous bag enclosing a part.

Carbon Dioxid, often called carbonic acid. The gas which is present in the air breathed out from the lungs; a waste product of the animal kingdom and a food of the vegetable kingdom.

Cardiac (Gr. καρδία, the heart). The cardiac orifice of the stomach is the upper one, and is near the heart; hence its name.

Carnivorous (Lat. caro, flesh, and voro, to devour). Subsisting upon flesh.

Carron Oil. A mixture of equal parts of linseed oil and lime-water, so called because first used at the Carron Iron Works in Scotland.

Cartilage. A tough but flexible material forming a part of the joints, air passages, nostrils, ear; gristle, etc.

Caruncle (Lat. caro, flesh). The small, red, conical-shaped body at the inner angle of the eye, consisting of a cluster of follicles.

Casein (Lat. caseus, cheese). The albuminoid substance of milk; it forms the basis of cheese.

Catarrh. An inflammation of a mucous membrane, usually attended with an increased secretion of mucus. The word is often limited to nasal catarrh.

Cauda Equina (Lat., horse’s tail). The collection of large nerves descending from the lower end of the spinal cord.

Cell (Lat. cella, a storeroom). The name of the tiny miscroscopic elements, which, with slender threads or fibers, make up most of the body; they were once believed to be little hollow chambers; hence the name.

Cement. The substance which forms the outer part of the fang of a tooth.

Cerebellum (dim. for cerebrum, the brain). The little brain, situated beneath the posterior third of the cerebrum.

Cerebrum. The brain proper, occupying the upper portion of the skull.

Ceruminous (Lat. cerumen, ear wax). A term applied to the glands secreting cerumen, or ear wax.

Chloral. A powerful drug and narcotic poison used to produce sleep.

Chloroform. A narcotic poison generally used by inhalation; of extensive use in surgical operations. It produces anÆsthesia.

Chondrin (Gr. χονδρός, cartilage). A kind of gelatine obtained by boiling cartilage.

ChordÆ TendineÆ. Tendinous cords.

Choroid (Gr. χορίον, skin, and εἶδος, form). The middle coat of the eyeball.

Chyle (Gr. χυλός, juice). The milk-like fluid formed by the digestion of fatty articles of food in the intestines.

Chyme (Gr. χυμός, juice). The pulpy liquid formed by digestion in the stomach.

Cilia (pl. of cilium, an eyelash). Minute hair-like processes found upon the cells of the air passages and other parts.

Ciliary Muscle. A small muscle of the eye which assists in accommodation.

Circumvallate (Lat. circum, around, and vallum, a rampart). Surrounded by a rampart, as are certain papillÆ of the tongue.

Coagulation (Lat. coagulo, to curdle). Applied to the process by which the blood clots or solidifies.

Cochlea (Lat. cochlea, a snail shell). The spiral cavity of the internal ear.

ColumnÆ CarneÆ. Fleshy projections in the ventricles of the heart.

Commissure (Lat. con, together, and mitto, missum, to put). A joining or uniting together.

Compress. A pad or bandage applied directly to an injury to compress it.

Concha (Gr. κόγχη, a mussel shell). The shell-shaped portion of the external ear.

Congestion (Lat. con, together, and gero, to bring). Abnormal gathering of blood in any part of the body.

Conjunctiva (Lat. con, together, and jungo, to join). A thin layer of mucous membrane which lines the eyelids and covers the front of the eyeball, thus joining the latter to the lids.

Connective Tissue. The network which connects the minute parts of most of the structures of the body.

Constipation (Lat. con, together, and stipo, to crowd close). Costiveness.

Consumption (Lat. consumo, to consume). A disease of the lungs, attended with fever and cough, and causing a decay of the bodily powers. The medical name is phthisis.

Contagion (Lat. con, with, and tango or tago, to touch). The communication of disease by contact, or by the inhalation of the effluvia of a sick person.

Contractility (Lat. con, together, and traho, to draw). The property of a muscle which enables it to contract, or draw its extremities closer together.

Convolutions (Lat. con, together, and volvo, to roll). The tortuous foldings of the external surface of the brain.

Convulsion (Lat. convello, to pull together). A more or less violent agitation of the limbs or body.

CoÖrdination. The manner in which several different organs of the body are brought into such relations with one another that their functions are performed in harmony.

Coracoid (Gr. κόραξ, a crow, εἶδος, form). Shaped like a crow’s beak.

Cornea (Lat. cornu, a horn). The transparent horn-like substance which covers a part of the front of the eyeball.

Coronary (Lat. corona, a crown). A term applied to vessels and nerves which encircle parts, as the coronary arteries of the heart.

Coronoid (Gr. κορώνη, a crow). Like a crow’s beak; thus the coronoid process of the ulna.

Cricoid (Gr. κρίκος, a ring, and εἶδος, form). A cartilage of the larynx resembling a seal ring in shape.

Crystalline Lens (Lat. crystallum, a crystal). One of the humors of the eye; a double-convex body situated in the front part of the eyeball.

Cumulative. A term applied to the violent action from drugs which supervenes after the taking of several doses with little or no effect.

Cuticle (Lat. dim. of cutis, the skin). Scarf skin; the epidermis.

Cutis (Gr. σκῦτος, a skin or hide). The true skin, also called the dermis.

Decussation (Lat. decusso, decussatum, to cross). The crossing or running of one portion athwart another.

Degeneration (Lat. degenerare, to grow worse, to deteriorate). A change in the structure of any organ which makes it less fit to perform its duty.

Deglutition (Lat. deglutire, to swallow). The process of swallowing.

Deltoid. Having a triangular shape; resembling the Greek letter Δ (delta).

Dentine (Lat. dens, dentis, a tooth). The hard substance which forms the greater part of a tooth; ivory.

Deodorizer. An agent which corrects any foul or unwholesome odor.

Dextrin. A soluble substance obtained from starch.

Diabetes Mellitus (Gr. διά, through, βαίνω, to go, and μέλι, honey). Excessive flow of sugar-containing urine.

Diaphragm (Gr. διαφράσσω, to divide by a partition). A large, thin muscle which separates the cavity of the chest from the abdomen.

Diastole (Gr. διαστέλλω, to dilate). The dilatation of the heart.

Dietetics. That part of medicine which relates to diet, or food.

Diffusion of Gases. The power of gases to become intimately mingled.

DiplÖe (Gr. διπλόω, to double, to fold). The osseous tissue between the tables of the skull.

Dipsomania (Gr. δίψα, thirst, and μανία, madness). An insatiable desire for intoxicants.

Disinfectants. Agents used to destroy the germs or particles of living matter that are believed to be the causes of infection.

Dislocation (Lat. dislocare, to put out of place). An injury to a joint in which the bones are displaced or forced out of their sockets.

Dissection (Lat. dis, apart, and seco, to cut). The cutting up of an animal in order to learn its structure.

Distal (Lat. dis, apart, and sto, to stand). Away from the center.

Duct (Lat. duco, to lead). A narrow tube.

Duodenum (Lat. duodeni, twelve). The first division of the small intestines, about twelve fingers’ breadth long.

Dyspepsia (Gr. -δύς, ill, and πέπτειν, to digest). A condition of the alimentary canal in which it digests imperfectly. Indigestion.

Dyspnoea (Gr. δύς, difficult, and πνέω, to breathe). Difficult breathing.

Efferent (Lat. effero, to carry out). Bearing or carrying outwards, as from the center to the periphery.

Effluvia (Lat. effluo, to flow out). Exhalations or vapors coming from the body, and from decaying animal or vegetable substances.

Element. One of the simplest parts of which anything consists.

Elimination (Lat. e, out of, and limen, liminis, a threshold). The act of expelling waste matters. Signifies, literally, “to throw out of doors.”

Emetic (Gr. ἐμέω, to vomit). A medicine which causes vomiting.

Emulsion (Lat. emulgere, to milk). Oil in a finely divided state, suspended in water.

Enamel (Fr. Émail). Dense material covering the crown of a tooth.

Endolymph (Gr. ἔνδον, within, and Lat. lympha, water). The fluid in the membranous labyrinth of the ear.

Endosmosis (Gr. ἔνδον, within, and ὠθέω, to push). The current from without inwards when diffusion of fluids takes place through a membrane.

Epidemic (Gr. ἐπί, upon, and δέμος, the people). An extensively prevalent disease.

Epiglottis (Gr. ἐπί, upon, and γλόττις, the entrance to the windpipe). A leaf-shaped piece of cartilage which covers the top of the larynx during the act of swallowing.

Epilepsy (Gr. ἐπίληψις, a seizure). A nervous disease accompanied by fits in which consciousness is lost; the falling sickness.

Ether (Gr. αἰθήρ, the pure, upper air). A narcotic poison. Used as an anÆsthetic in surgical operations.

Eustachian (from an Italian anatomist named Eustachi). The tube which leads from the throat to the middle ear, or tympanum.

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

Exosmosis (Gr. ἔξω, without, and ᾀθέω, 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 albuminoid 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. γάγγλιν, a knot). A knot-like swelling in a nerve; a smaller nerve center.

Gastric (Gr. γαστήρ, 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. γλόττα, 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 albuminoid 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. γυμνάξω, to exercise). The practice of athletic exercises.

HÆmoglobin (Gr. αἷμα, blood, and Lat. globus, a globe or globule). A complex substance which forms the principal coloring constituent of the red corpuscles of the blood.

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

Hemorrhage (Gr. αἷμα, blood, and ῥήγνυμι, to burst). Bleeding, or the loss of blood.

Hepatic (Gr. ἧπαρ, 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.

Homogeneous (Gr. ὁμός, the same, and γένος, kind). Of the same kind or quality throughout; uniform in nature,—the reverse of heterogeneous.

Humor. The transparent contents of the eyeball.

Hyaline (Gr. ὕαλος, glass). Glass-like, resembling glass in transparency.

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

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

Hygiene (Gr. ὑγἰεια health). The art of preserving health and preventing disease.

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

Hypermetropia (Gr. ὑπέρ over, beyond, μέτρον, measure, and ώ̓ψ, the eye). Far-sightedness.

Hypertrophy (Gr. ὑπέρ, over, and τροφή, nourishment). Excessive growth; thickening or enlargement of any part or organ.

Incisor (Lat. incido, to cut). Applied to the four front teeth of both jaws, which have sharp, cutting edges.

Incus. An anvil; the name of one of the bones of the middle ear.

Indian Hemp. The common name of Cannabis Indica, an intoxicating drug known as hasheesh and by other names in Eastern countries.

Inferior Vena Cava. The chief vein of the lower part of the body.

Inflammation (Lat. prefix in and flammo, to flame). A redness or swelling of any part of the body with heat and pain.

Insalivation (Lat. in and saliva, the fluid of the mouth). The mingling of the saliva with the food during the act of chewing.

Inspiration (Lat. inspiro, spiratum, to breathe in). The act of drawing in the breath.

Intestine (Lat. intus, within). The part of the alimentary canal which is continuous with the lower end of the stomach; also called the bowels.

Iris (Lat. iris, the rainbow). The thin, muscular ring which lies between the cornea and crystalline lens, giving the eye its special color.

Jaundice (Fr. jaunisse, yellow). A disorder in which the skin and eyes assume a yellowish tint.

Katabolism (Gr. καταβάλλω, to throw down). The process by means of which the more complex elements are rendered more simple and less complex. The opposite of anabolism.

Labyrinth. The internal ear, so named from its many windings.

Lacrymal Apparatus (Lat. lacryma, a tear). The organs for forming and carrying away the tears.

Lacteals (Lat. lac, lactis, milk). The absorbent vessels of the small intestines.

Laryngoscope (Gr. λάρυγξ, larynx, and σκοπέω, to behold). An instrument consisting of a mirror held in the throat, and a reflector to throw light on it, by which the interior of the larynx is brought into view.

Larynx. The cartilaginous tube situated at the top of the windpipe.

Lens. Literally, a lentil; a piece of transparent glass or other substance so shaped as either to converge or disperse the rays of light.

Ligament (Lat. ligo, to bind). A strong, fibrous material binding bones or other solid parts together.

Ligature (Lat. ligo, to bind). A thread of some material used in tying a cut or injured artery.

Lobe. A round, projecting part of an organ, as of the liver, lungs, or brain.

Lymph (Lat. lympha, pure water). The watery fluid conveyed by the lymphatic vessels.

Lymphatic Vessels. A system of absorbent vessels.

Malleus. Literally, the mallet; one of the small bones of the middle ear.

Marrow. The soft, fatty substance contained in the cavities of bones.

Mastication (Lat. mastico, to chew). The act of cutting and grinding the food to pieces by means of the teeth.

Meatus (Lat. meo, meatum, to pass). A passage or canal.

Medulla Oblongata. The “oblong marrow”; that portion of the brain which lies upon the basilar process of the occipital bone.

Meibomian. A term applied to the small glands between the conjunctiva and tarsal cartilages, discovered by Meibomius.

Membrana Tympani. Literally, the membrane of the drum; a delicate partition separating the outer from the middle ear; it is sometimes popularly called “the drum of the ear.”

Membrane. A thin layer of tissue serving to cover some part of the body.

Mesentery (Gr. μέσος, middle, and ἔντερον, the intestine). A duplicature of the peritoneum covering the small intestine, which occupies the middle or center of the abdominal cavity.

Metabolism (Gr. μεταβολή, change). The changes taking place in cells, whereby they become more complex and contain more force, or less complex and contain less force. The former is constructive metabolism, or anabolism; the latter, destructive metabolism, or katabolism.

Microbe (Gr. μικρός, little, and βίος, life). A microscopic organism, particularly applied to bacteria.

Microscope (Gr. μικρός, small, and σκοπέω, to look at). An optical instrument which assists in the examination of minute objects.

Molar (Lat. mola, a mill). The name applied to the three back teeth at each side of the jaw; the grinders, or mill-like teeth.

Molecule (dim. of Lat. moles, a mass). The smallest quantity into which the mass of any substance can physically be divided. A molecule may be chemically separated into two or more atoms.

Morphology (Gr. μόρφη, form, and λόγος, discourse). The study of the laws of form or structure in living beings.

Motor (Lat. moveo, motum, to move). The name of the nerves which conduct to the muscles the stimulus which causes them to contract.

Mucous Membrane. The thin layer of tissue which covers those internal cavities or passages which communicate with the external air.

Mucus. The glairy fluid secreted by mucous membranes.

Myopia (Gr. μύω, to shut, and ὤψ, the eye). A defect of vision dependent upon an eyeball that is too long, rendering distant objects indistinct; near sight.

Myosin (Gr. μῶς, muscle). Chief proteid substance of muscle.

Narcotic (Gr. ναρκάω, to benumb). A medicine which, in poisonous doses, produces stupor, convulsions, and sometimes death.

Nerve Cell. A minute round and ashen-gray cell found in the brain and other nervous centers.

Nerve Fiber. An exceedingly slender thread of nervous tissue.

Nicotine. The poisonous and stupefying oil extracted from tobacco.

Nostril (Anglo-Saxon nosu, nose, and thyrl, a hole). One of the two outer openings of the nose.

Nucleolus (dim. of nucleus). A little nucleus.

Nucleus (Lat. nux, a nut). A central part of any body, or that about which matter is collected. In anatomy, a cell within a cell.

Nutrition (Lat. nutrio, to nourish). The processes by which the nourishment of the body is accomplished.

Odontoid (Gr. ὀδούς, a tooth, εἶδσ, shape). The name of the bony peg of the second vertebra, around which the first turns.

Œsophagus. Literally, that which carries food. The tube leading from the throat to the stomach; the gullet.

Olecranon (Gr. ὠλένη, the elbow, and κρανίον, the top of the head). A curved eminence at the upper and back part of the ulna.

Olfactory (Lat. olfacio, to smell). Pertaining to the sense of smell.

Optic (Gr. ὀπτεύω, to see). Pertaining to the sense of sight.

Orbit (Lat. orbis, a circle). The bony socket or cavity in which the eyeball is situated.

Organ (Lat. organum, an instrument or implement). A portion of the body having some special function or duty.

Osmosis (Gr. ὠσμός, impulsion). Diffusion of liquids through membranes.

Ossa Innominata, pl. of Os Innominatum (Lat.). “Unnamed bones.” The irregular bones of the pelvis, unnamed on account of their non-resemblance to any known object.

Otoconia (Gr. οὖς, an ear, and κονία, dust). Minute crystals of lime in the vestibule of the ear; also known as otoliths.

Palate (Lat. palatum, the palate). The roof of the mouth, consisting of the hard and soft palate.

Palpitation (Lat. palpitatio, a frequent or throbbing motion). A violent and irregular beating of the heart.

Papilla. The small elevations found on the skin and mucous membranes.

Paralysis (Gr. παραλύω, to loosen; also, to disable). Loss of function, especially of motion or feeling. Palsy.

Parasite. A plant or animal that grows or lives on another.

Pelvis. Literally, a basin. The bony cavity at the lower part of the trunk.

Pepsin (Gr. πέπτω, to digest). The active principle of the gastric juice.

Pericardium (Gr. περί, about, and καρδία, heart). The sac enclosing the heart.

Periosteum (Gr. περί, around, ὀστέον, a bone). A delicate fibrous membrane which invests the bones.

Peristaltic Movements (Gr. περί, round, and στέλλω, to send). The slow, wave-like movements of the stomach and intestines.

Peritoneum (Gr. περιτείνω, to stretch around). The investing membrane of the stomach, intestines, and other abdominal organs.

Perspiration (Lat. perspiro, to breathe through). The sweat.

Petrous (Gr. πέτρα, a rock). The name of the hard portion of the temporal bone, in which are situated the drum of the ear and labyrinth.

Phalanges (Gr. φάλαγξ, a body of soldiers closely arranged in ranks and files). The bones of the fingers and toes.

Pharynx (Gr. φάρμγξ, the throat). The cavity between the back of the mouth and the gullet.

Physiology (Gr. φύσις, nature, and λόγος, a discourse). The science of the functions of living, organized beings.

Pia Mater (Lat.). Literally, the tender mother; the innermost of the three coverings of the brain. It is thin and delicate; hence the name.

Pinna (Lat. a feather or wing). External cartilaginous flap of the ear.

Plasma (Gr. πλάσσω, to mould). Anything formed or moulded. The liquid part of the blood.

Pleura (Gr. πλευρά, the side, also a rib). A membrane covering the lung, and lining the chest.

Pleurisy. An inflammation affecting the pleura.

Pneumogastric (Gr. πνεύμων, the lungs, and γαστήρ, the stomach). The chief nerve of respiration; also called the vagus, or wandering nerve.

Pneumonia. An inflammation affecting the air cells of the lungs.

Poison (Fr. poison). Any substance, which, when applied externally, or taken into the stomach or the blood, works such a change in the animal economy as to produce disease or death.

Pons Varolii. Bridge of Varolius. The white fibers which form a bridge connecting the different parts of the brain, first described by Varolius.

Popliteal (Lat. poples, poplitis, the ham, the back part of the knee). The space behind the knee joint is called the popliteal space.

Portal Vein (Lat. porta, a gate). The venous trunk formed by the veins coming from the intestines. It carries the blood to the liver.

Presbyopia (Gr. πρέσβυς, old, and ὤψ, the eye). A defect of the accommodation of the eye, caused by the hardening of the crystalline lens; the “far sight” of adults and aged persons.

Process (Lat. procedo, processus, to proceed, to go forth). Any projection from a surface; also, a method of performance; a procedure.

Pronation (Lat. pronus, inclined forwards). The turning of the hand with the palm downwards.

Pronator. The group of muscles which turn the hand palm downwards.

Proteids (Gr. πρῶτος, first, and εἶδος, form). A general term for the albuminoid constitutents of the body.

Protoplasm (Gr. πρῶτος, first, and πλάσσω, to form). A first-formed organized substance; primitive organic cell matter.

Pterygoid (Gr. πτέρων, a wing, and εἶδος, form, resemblance). Wing-like.

Ptomaine (Gr. πτῶμα, a dead body). One of a class of animal bases or alkaloids formed in the putrefaction of various kinds of albuminous matter.

Ptyalin (Gr. σίαλον, saliva). A ferment principle in saliva, having power to convert starch into sugar.

Pulse (Lat. pello, pulsum, to beat). The throbbing of an artery against the finger, occasioned by the contraction of the heart. Commonly felt at the wrist.

Pupil (Lat. pupilla). The central, round opening in the iris, through which light passes into the interior of the eye.

Pylorus (Gr. πυλουρός, a gatekeeper). The lower opening of the stomach, at the beginning of the small intestine.

Reflex (Lat. reflexus, turned back). The name given to involuntary movements produced by an excitation traveling along a sensory nerve to a center, where it is turned back or reflected along motor nerves.

Renal (Lat. ren, renis, the kidney). Pertaining to the kidneys.

Respiration (Lat. respiro, to breathe frequently). The function of breathing, comprising two acts,—inspiration, or breathing in, and expiration, or breathing out.

Retina (Lat. rete, a net). The innermost of the three tunics, or coats, of the eyeball, being an expansion of the optic nerve.

Rima Glottidis (Lat. rima, a chink or cleft). The opening of the glottis.

Saccharine (Lat. saccharum, sugar). The group of food substances which embraces the different varieties of sugar, starch, and gum.

Saliva. The moisture, or fluids, of the mouth, secreted by the salivary glands; the spittle.

Sarcolemma (Gr. σάρξ, flesh, and λέμμα, a husk). The membrane which surrounds the contractile substance of a striped muscular fiber.

Sclerotic (Gr. σκληρός, hard). The tough, fibrous, outer coat of the eyeball.

Scurvy. Scorbutus,—a disease of the general system, having prominent skin symptoms.

Sebaceous (Lat. sebum, fat). Resembling fat; the name of the oily secretion by which the skin is kept flexible and soft.

Secretion (Lat. secerno, secretum, to separate). The process of separating from the blood some essential, important fluid; which fluid is also called a secretion.

Semicircular Canals. Three canals in the internal ear.

Sensation. The perception of an external impression by the nervous system.

Serum. The clear, watery fluid which separates from the clot of the blood.

Spasm (Gr. σπασμός, convulsion). A sudden, violent, and involuntary contraction of one or more muscles.

Special Sense. A sense by which we receive particular sensations, such as those of sight, hearing, taste, and smell.

Sputum, pi. Sputa (Lat. spuo, sputum, to spit). The matter which is coughed up from the air passages.

Stapes. Literally, a stirrup; one of the small bones of the middle ear.

Stimulant (Lat. stimulo, to prick or goad on). An agent which causes an increase of vital activity in the body or in any of its parts.

Striated (Lat. strio, to furnish with channels). Marked with fine lines.

Styptics (Gr. στυπτικός astringent). Substances used to produce a contraction or shrinking of living tissues.

Subclavian Vein (Lat. sub, under, and clavis, a key). The great vein bringing back the blood from the arm and side of the head; so called because it is situated underneath the clavicle, or collar bone.

Superior Vena Cava (Lat., upper hollow vein). The great vein of the upper part of the body.

Suture (Lat. sutura, a seam). The union of certain bones of the skull by the interlocking of jagged edges.

Sympathetic System of Nerves. A double chain of nervous ganglia, situated chiefly in front of, and on each side of, the spinal column.

Symptom (Gr. σύν, with, and πίπτω, to fall). A sign or token of disease.

Synovial (Gr. σύν, with, and ὠόν, an egg). The liquid which lubricates the joints; joint-oil. It resembles the white of a raw egg.

System. A number of different organs, of similar structures, distributed throughout the body and performing similar functions.

Systemic. Belonging to the system, or body, as a whole.

Systole (Gr. συστέλλω, to contract). The contraction of the heart, by which the blood is expelled from that organ.

Tactile (Lat. tactus, touch). Relating to the sense of touch.

Tartar. A hard crust which forms on the teeth, and is composed of salivary mucus, animal matter, and a compound of lime.

Temporal (Lat. tempus, time, and tempora, the temples). Pertaining to the temples; so called because the hair begins to turn white with age in that portion of the scalp.

Tendon (Lat. tendo, to stretch). The white, fibrous cord, or band, by which a muscle is attached to a bone; a sinew.

Tetanus (Gr. τείνω, to stretch). A disease marked by persistent contractions of all or some of the voluntary muscles; those of the jaw are sometimes solely affected; the disorder is then termed lockjaw.

Thorax (Gr. θώραξ, a breast-plate). The upper cavity of the trunk of the body, containing the lungs, heart, etc.; the chest.

Thyroid (Gr. εἶδος, a shield, and εἶ̓δος, form). The largest of the cartilages of the larynx: its projection in front is called “Adam’s Apple.”

Tissue. Any substance or texture in the body formed of various elements, such as cells, fibers, blood-vessels, etc., interwoven with each other.

Tobacco (Indian tabaco, the tube, or pipe, in which the Indians smoked the plant). A plant used for smoking and chewing, and in snuff.

Trachea (Gr. τραχύς, rough). The windpipe.

Tragus (Gr. τράγος, a goat). The eminence in front of the opening of the ear; sometimes hairy, like a goat’s beard.

Transfusion (Lat. transfundo, to pour from one vessel to another). The operation of injecting blood taken from one person into the veins of another.

Trichina Spiralis. (A twisted hair). A minute species of parasite, or worm, which infests the flesh of the hog: may be introduced into the human system by eating pork not thoroughly cooked.

Trochanter (Gr. τροχάω, to turn, to revolve). Name given to two projections on the upper extremities of the femur, which give attachment to the rotator muscles of the thigh.

Trypsin. The ferment principle in pancreatic juice, which converts proteid material into peptones.

Tubercle (Lat. tuber, a bunch). A pimple, swelling, or tumor. A morbid product occurring in certain lung diseases.

Tuberosity (Lat. tuber, tuberis, a swelling). A protuberance.

Turbinated (Lat. turbinatus, from turbo, turbinis, a top). Formed like a top; a name given to the bones in the outer wall of the nasal fossÆ.

Tympanum (Gr. τύμπανον, a drum). The cavity of the middle ear, resembling a drum in being closed by two membranes.

Umbilicus (Lat., the navel.) A round cicatrix or scar in the median line of the abdomen.

Urea (Lat. urina, urine). Chief solid constitutent of urine. Nitrogenous product of tissue decomposition.

Ureter (Gr. οὐρέω, to pass urine). The tube through which the urine is conveyed from the kidneys to the bladder.

Uvula (Lat. uva, a grape). The small, pendulous body attached to the back part of the palate.

Vaccine Virus (Lat. vacca, a cow, and virus, poison). The material derived from heifers for the purpose of vaccination,—the great preventive of smallpox.

Valvulae Conniventes. A name given to transverse folds of the mucous membrane in the small intestine.

Varicose (Lat. varix, a dilated vein). A distended or enlarged vein.

Vascular (Lat. vasculum, a little vessel). Pertaining to or possessing blood or lymph vessels.

Vaso-motor (Lat. vas, a vessel, and moveo, motum, to move). Causing motion to the vessels. Vaso-motor nerves cause contraction and relaxation of the blood-vessels.

VenÆ CavÆ, pl. of Vena Cava. “Hollow veins.” A name given to the two great veins of the body which meet at the right auricle of the heart

Venous (Lat. vena, a vein). Pertaining to, or contained within, a vein. Ventilation. The introduction of fresh air into a room or building in such a manner as to keep the air within it in a pure condition.

Ventral (Lat. venter, ventris, the belly). Belonging to the abdominal or belly cavity.

Ventricles of the Heart. The two largest cavities of the heart.

Vermiform (Lat. vermis, a worm, and forma, form). Worm-shaped.

Vertebral Column (Lat. vertebra, a joint). The backbone; also called the spinal column and spine.

Vestibule. A portion of the internal ear, communicating with the semicircular canals and the cochlea, so called from its fancied resemblance to the vestibule, or porch, of a house.

Villi (Lat. villus, shaggy hair). Minute, thread-like projections upon the internal surface of the small intestine, giving it a velvety appearance.

Virus (Lat., poison). Foul matter of an ulcer; poison.

Vital Knot. A part of the medulla oblongata, the destruction of which causes instant death.

Vitreous (Lat. vitrum, glass). Having the appearance of glass; applied to the humor occupying the largest part of the cavity of the eyeball.

Vivisection (Lat. vivus, alive, and seco, to cut). The practice of operating upon living animals, for the purpose of studying some physiological process.

Vocal Cords. Two elastic bands or ridges situated in the larynx; the essential parts of the organ of voice.

Zygoma (Gr. ζυγώς, a yoke). The arch formed by the malar bone and the zygomatic process of the temporal bone.