A small bone. Auditory ossicles or chain of small bones found in the
middle ear. They are the incus, stapes, and malleus.
Ossification. From the Latin words os, "a bone;" facere, "to make.")
The process of bone formation.
Osteoblasts. Cells concerned in the formation of bony tissue
steoclasts. The multinuclear (many nuclei) cells found against
the surface of bone in little eroded depressions (Howship's fovea),
and concerned in the removal of bone.
Ostium Uterinum or Uteri. The mouth of the uterus (womb) .
Ovum. (From the Latin word ovum, "an egg.") The reproductive
cell of an animal or vegetable, an egg.
Oxidation. (From the Greek word meaning sharp.) The act or
process of combining with oxygen, as the hemoglobin of the red cells
does during respiration, and the cells of the tissues combine with it
as the hemoglobin of the red cells in the blood gives it up upon reaching
them. Oxidation is essential to body metabolism.
Oxygen. Is a colorless, tasteless, odorless gas, one of the non-
metallic elements. It constitutes one-fifth of the atmosphere, eight-
ninths of water, three-fourths of organized bodies, and about one-half
the crust of the globe. It is essential to combustion or burning with
the elimination of heat and light when oxidation takes place. It is not
a food, but is essential to the act of respiration. Its absence causes
asphyxia or suffocation.
Palate. The roof of the mouth.
Palmaris Brevis (muscle). The short one of the palm.
Palmaris Longus (muscle). The long one of the palm.
Palpebral. Pertaining to the eyelid.
Papilla (pi. se). (From the Latin papilla, "a nipple.") A small
Parietal. (From the Latin word paries, "a wall.") Forming or
pertaining to the wall of a cavity, or portion of a membrane attached to
it, as parietal peritoneum, etc.
Pars Intermedius. The part between, referring to the nervus
intermedius.) (See N. intermedius.)
Parturition. (From the Latin word parturitio, from partuire, "to
bring forth.") The act of giving birth to the young.
Patella (bone). (From the Latin word a dim. of patera, "a shallow
dish.") The knee-pan, or knee-cap; a round small bone in front of
the knee, developed in the tendon of the quadriceps extensor muscle.
Pectoral. (From the Latin word pectus, "a breast.") Pertaining
to the chest.
Pectoralis Major (muscle). The larger one of the chest.
Pectoralis Minor (muscle). The smaller one of the chest.
Pedicle. (From the Latin word pediculus, dim. of pes, pedis, "a
foot.") A slender process acting as a foot or stem.
Peduncle. (From pedunculus, a dim. of pes, "a foot.") A narrow
part acting as a support.
Pelvic. Pertaining to the pelvis.
Pelvis. (From the Latin word pelvis, "a basin.") A basin-shaped
cavity. The bony ring formed by the two innominate bones and the
sacrum and coccyx.
Peptone. The final protein body or substance formed by the action
of ferments on albumins during gastric and pancreatic digestion.
Peri. A Greek prefix signifying around.
Pericardium. (Around the heart.) The serous membrane sur-
rounding the heart.
Perichondrium. The fibrous connective tissue surrounding the
surface of cartilage.
Perimysium. (Around a muscle.) The connective tissue surrounding
the primary bundles of muscle fibers.
Perineum. That portion of the body corresponding to the struc-
tures overlying the outlet of the pelvis.
Periosteum. (Around bone.) A fibrous membrane investing the
surface of bones.
Peripheral. Pertaining to or placed near the periphery.
Periphery. (From the Greek words meaning around, to carry.)
The circumference; the external surface, or extreme portions of the
body or an organ.
Peristalsis. A peculiar wave-like movement seen in tubes provided
with longitudinal, transverse, and oblique muscle fibers, as the intes-
tinal canal, stomach, etc.
Peristaltic. Pertaining to peristalsis.
Peritendineum. (Around a tendon.) The fibrous sheath investing
the small bundles of tendon fibers.
Peritoneum. (From the Greek words meaning around, to stretch.)
The serous membrane lining the interior of the abdominal cavity and
surrounding the contained viscera. It forms folds for the support of
organs called ligaments (of liver, uterus, etc.); attaches organs to
each other, as omentum when another organ is connected to the
stomach, thus gastrqsplenic omentum; as the intestines are held to
the posterior abdominal wall: thus the mesentery; as the colon is
attached to the wall of the abdomen : thus the mesocolon. The organs
behind the peritoneum are spoken of as retroperitoneal organs.
Peroneal. Pertaining to the fibula bone. The region overlying the
Peroneus Brevis (muscle). The short peroneal.
Peroneus Longus (muscle). The long peroneal.
Pes Anserinus. (From the Latin word pes, "a foot;" anserinus, "a
goose"). A goose foot; named, as the branches of the facial nerve are
supposed to spread like the toes of a goose foot.
Petrous. (From Greek word meaning rock, stony, of the hardness
Phalanx (pi. phalanges). One of the bones of the fingers or toes.
Pharynx. (From the Greek word meaning throat). The musculo-
membranous tube situated back of the nose, mouth, and larynx.
Phrenic. Pertaining to the diaphragm or diaphragmatic region,
Pia Mater. (From the Latin words pia, " tender;" mater, "mother.")
The tender mother. The vascular membrane enveloping the surface
of the brain and spinal cord.
Pigment. (From the Latin word pingere, "to paint.") A coloring
matter, or dye-stuff. Pigments may be in solution or in the form of
granules or crystals; as the pigment of skin in negroes, etc.; iris of eye.
Pisiform (bone). (From the Latin words pisum, "a pea;" forma,
"form.") Pea-shaped. A bone of the wrist.
Placenta. (From the Greek word meaning a cake.) The organ on
the wall of the uterus to which the embryo is attached by means of
the umbilical cord and from which it receives its nourishment and
excretes the waste products from about the third month of gestation
to the birth of the child (parturition). It is called the "after-birth"
by the laity.
Placental. Referring to the placenta.
Plantar. (From the Latin word planta, "the sole of the foot.")
Referring to the sole of the foot.
Plasma. The fluid part of the blood and lymph.
Platysma Myoides (muscle) . . The broad muscle (from the Greek) .
Pleura. (From the Greek word meaning a rib.) The serous mem-
brane covering the lungs and inner surface of the wall of the thoracic
Pollicis. (From the Latin word pollen, pollicis, "the thumb.")
Of the thumb.
Polygonal. Having many angles.
Polyhedral. Having many sides.
Potential (energy). (From the Latin word potens, "able.") Capable
of acting or doing work.
Poupart's Ligament. The ligament extending from the anterior
superior spine of the iliac bone to the spine of the pubic bone. It is
the lower border of the aponeurosis of the external oblique muscle of
Pretracheal. In front of the trachea.
Prevertebral. In front of the vertebral column.
Proligerous (disk). (From the Latin word proles, "offspring;"
gere, "to bear.") Producing offspring. The layer of cells in the
membrana granulosa of the Graafian follicle that surrounds the ovum.
Pronation. (From the Latin word pronare, "to bend forward.")
The act of turning the palm downward; the opposite of supination.
Pronator Quadratus (muscle). Square pronator. See pronation.
Pronator Radii Teres (muscle). The round pronator of the radius.
Protein or Proteid. Any one of the important and essential con-
stituents of animal and vegetable tissues containing nitrogen.
Proteo lysis. The change produced in proteins or proteids by fer-
ments that convert them into diffusible bodies.
Proteolytic Ferments. Pertaining to those ferments which are
characterized or effect proteolysis.
Proteose. Any one of a group of bodies formed in gastric digestion
intermediate between the food proteins and peptones, called anti-
Protoplasm. The viscid material constituting the essential sub-
stance of living cells, upon which all the vital functions of nutrition,
secretion, growth, reproduction, irritability, motility depend.
Proximal. (From the Latin word proximus, ' ' the nearest . " ) Nearest
to the body, or the median line of the body. Proximal phalanx: The
nearest bone of the finger.
Proximate (principles) . (From the Latin word proximus, ' ' nearest . " )
Nearest. Proximate principles, substances which can exist under
their own form in the animal solids or fluids, and that can be extracted
by means not altering or destroying their chemic properties.
Puberty. From the Latin word pubertas, from puber, "adult.")
The period at which the generative organs become active in both
sexes, and become capable of reproduction.
Pubes. The hairy region covering the os pubis (pubic bone).
Pubic. Pertaining to the pubes.
Pubis (Os). The bone of the pubes. The lower and anterior part
of the innominate bone.
Pyloric. Pertaining to the pylorus of the stomach, as pyloric artery,
Pylorus. (From the Greek word meaning gate-keeper.) The
circular opening of the stomach into the duodenum.
Pyramidal. Shaped like a pyramid.
Pyramidalis (muscle). The muscle shaped like a pyramid found
at the lower part and inserted into the linea alba of the abdominal
wall. There are two.
Pyramidalis Nasi (muscle). The pyramidal one of the nose.
Quadratus. Squared; four-sided.
Quadrangular. Having four angles.
Quadriceps (extensor tendon). The four-headed extensor tendon.
Racemose. (From the Latin word racemus, "a bunch of grapes.")
Resembling a bunch of grapes.
Radius (bone). (From the Latin word radius, "the spoke of a
wheel.") The outer bone of the forearm.
Rami Communicantes. (From the Latin words ramus (pi. i), "a
branch;" communicans (pi. antes), "communicating.") Communi-
cating branches. The branches of a spinal nerve connecting it with
the sympathetic ganglia.
Reflex (action). (From the Latin words re, "back;" flectere, "to
bend.") Anything bended or thrown back. Reflex act: An act
following immediately upon a stimulus without the intervention
of the will.
Refractory (apparatus). (From the Latin words re, "back;" fran-
gere, "to break.") Literally, to break the natural course of, as rays
of light; to cause them to deviate from a direct course, as the refractory
apparatus of the eye deviates the rays of light as to how they shall
fall upon the retina (diffuse or concentrated), based upon the nearness
or distance of an object to or from the eye.
Renal. (From the Latin word ren, "a kidney.") Pertaining to
Renalis (fascia). Fascia of the kidney.
Renes (pi. of ren.). The kidneys.
Reticular. (From the Latin word reticulum, dim. of rete, "a net.")
Resembling a net, formed by a net-work, as reticular tissue.
Reticulum. A net-work.
Retiform. Having the form of a net.
Rhythmical. Pertaining to rhythm. In speaking of the heart and
pulse it refers to the dividing of their actions (contraction and relaxa-
tion) into short portions or periods by a regular succession of motions.
Rima Glottidis. The chink of the glottis. The cleft or narrow
opening between the true vocal cords in the larynx.
Risorius (muscle). (From the Latin word ridere, "to laugh.")
The laughing muscle.
Rotation. (From the Latin words rotare, "to turn;" from rota, "a
wheel.") The act of turning about an axis, passing through the centre
of a body or extremity.
Rugae. (Plural of ruga, "a fold or ridge.") Folds.
Saccharoses. (From the Greek word meaning sugar.) A group of
carbohydrates occurring in the juice of many plants, chiefly sugar-cane,
some varieties of maple and beet-sugar.
Sacrum (bone). (From the Latin word sacer, "sacred;" os, under-
Sagittal. (From the Latin word sagitta, "an arrow.") Arrow-like,
as the sagittal suture of the skull. Referring to the anteroposterior
middle plane of the body, or organ, etc.
Saphenous. Apparent, superficial; applied to the saphenous vein
of the thigh and leg, lying just beneath the skin and superficial
Sarcolemma. The delicate membrane enveloping a muscle fiber.
Sarcoplasm. The finely granular material between the fibrils of
Sartorius (muscle). (From the Latin word sartor, "a, tailor.")
The tailor muscle. Named after the ancient method the tailor assumed
while at work, squatting with his knees bent, and the feet and leg
Scaphoid (bone). Boat-shaped. A bone of the wrist and instep.
Scapula (bone). (From the Latin.) A shoulder-blade.
Secretion. (From the Latin word secernere, "to secrete, separate.")
1. The act of secreting or forming from materials furnished by the
blood a certain substance which is either eliminated by the body or
is used in carrying on certain functions. 2. The substance secreted,
as bile, sweat, etc.
Secretor or Secretory. Pertaining to or performing secretion of a
Sella Turcica. (A Turkish saddle.) The pituitary fossa of the
body of the sphenoid bone, lodging the pituitary body.
Semilunar. (From the Latin words semi, "half;" luna, "moon.")
Resembling a half -moon in shape.
Semimembranosus (muscle). Half-membrane.
Semitendinosus (muscle). Half -tendon.
Septum (pi. septa). (From the Latin word sepire, "to hem in.")
A partition, a dividing wall, as nasal septum, etc.
Sensor or Sensory. (From the Latin word sentire, "to feel.")
Pertaining to or conveying sensation, as a sensor nerve.
Serous (membrane). Pertaining to or resembling serum.
Serum. (From the Latin word serum, "serum.") 1. The clear,
yellowish fluid separating from the blood after the coagulation of the
fibrin. 2. Any clear fluid resembling the serum of the blood.
Sigmoid. Shaped like the Greek letter 2.
Sinus. A hollow or cavity.
Soleus (muscle). A flat muscle of the calf.
Solitary. (From the Latin word solitarius, "solitary.") Single,
Specific Gravity. The measured weight of a substance compared
with that of an equal volume of another taken as a standard.
Spheric. Having the shape of a sphere.
Sphincter. A muscle surrounding and closing an orifice; as sphincter
Spicule. A minute, sharp-pointed body, as a spicule of bone.
Spinal (nerve). 1. Pertaining to the spine. 2. Pertaining to the
Spinus. (From the Latin word spina, "a spine or thorn.") Resem-
bling or pertaining to a spine.
Squamous. (From the Latin word squamosis, "scaly.") Of the
shape of a scale.
Stellate. (From the Latin word stella, "a star.") Star-shaped.
Sternohyoid (muscle). From the sternum to the hyoid bone.
Sternomastoid (muscle). From the sternum to the rnastoid.
Sternothyroid (muscle) . From the sternum to the thyroid cartilage.
Sternum. Breast bone.
Stratified. (From the Latin word stratum, "a layer;" facere, "to
make.") Formed into a layer or layers.
Stratum Germinatum. The sprouting layer (skin).
Stratum Granulosum. The granular layer (skin).
Stratum Lucidum. The clear layer (skin) .
Stratum Mucosum. The mucous layer (skin).
Stroma. The tissue forming the frame-work for the necessary part
of an organ or tissue.
Stylohyoid. Pertaining to the styloid process of the temporal bone
and the hyoid bone.
Styloid. Resembling a pillar.
Sub. A prefix denoting under or beneath.
Subaponeurotic. Beneath the aponeurosis.
Subclavian. Beneath the clavicle.
Subclavius (muscle). Beneath the clavicle.
Subcostal. Beneath a rib.
Subcutaneous. Beneath the skin.
Subendpthelial. Beneath the endothelium. (See endothelium.)
Subpubic. Beneath the symphysis pubes.
Sulcus. A furrow or groove. (From the Latin )
Sulcus Pulmonalis. The groove of the lung.
Superciliary. (From the Latin words super, " above;" cilium, "an
eyelash.) Pertaining to the eyebrow.
Supination. (From the Latin word supinus, "on the back.") The
act of turning the palm of the hand upward. The condition of being
on the back. Opposite of pronation.
Supinator Brevis (muscle). The short supinator (assists to turn the
Supinator Longus (muscle). The long supinator (assists to turn
the palm upward).
Supracondylar. Above the condyle.
Suprapatellar. Above the patella.
Suprarenal. Above the kidney.
Sutural. (From the Latin word sutura, "a suture;" from sutere,
"to sew or stitch.") Pertaining to suture.
Suture. A suture. The seam or joint which unites the bones of
Symphysis (pubes). The line of junction of two bones Sym-
physis pubis: The line of junction of the two bodies of the pubic bones
located at the front of the true pelvis.
Synarthrosis. A form of joint or articulation in which the bones
are firmly bound together and are immovable. They have no synovial
Synchondrosis. A joint in which the surfaces of bones are connected
by a cartilage.
Syndesmosis. A form of joint in which the bones are held together
Synovia. The clear, alkaline, lubricating fluid secreted by the cells
of a synovial membrane, found within a synovial sac.
Synovial. Pertaining to the synovia.
Systole. (From the Greek words together, to place.) The con-
traction of the heart muscle. Auricular systole, the contraction of
the auricle of the heart; ventricular systole, the contraction of the
ventricle of the heart.
Tactile. (From the Latin word tactus, from tangere, "to touch.")
Pertaining to the sense of touch.
Tarsus. The instep.
Temporal (bone). (From the Latin word tempus, "time (temple).")
Pertaining to the temple, as temporal bone, artery, etc.
Tendo Achillis. The tendon of Achilles. (Tendon, from the Latin
word tendere, "to stretch.") The common tendon of the gastrocne-
mius and soleus muscles.
Tendo Oculi. The tendon of the eyeball.
Tensor Vaginae or Fasciae Femoris. The stretcher of the sheath
(fascia lata) of the thigh.
Tentorium Cerebelli. The tent of the cerebellum. The partition
of dura mater between the cerebrum and cerebellum.
Thenar. (From the Greek word meaning palm.) 1. The palm of
the hand. 2. The fleshy prominence of the palm corresponding to the
base of the thumb; also called thenar eminence (ball of the thumb).
Thermal. Pertaining to heat.
Thermic. Pertaining to heat.
Thoracic. Pertaining to or situated in the thorax or chest.
Thorax. From the Greek word meaning chest.
Thyrohyoid (muscle). From the thyroid cartilage to the hyoid bone,
as thyrohyoid muscle and membrane.
Thyroid. Shield-shaped. Pertaining to the thyroid gland, cartilage,
Tibia (bone). (From the Latin word tibia, "a shin.") The large
bone on the inner side of the leg.
Tibiofibular (articulation). Pertaining to the tibia and fibula.
Tissue. (From the Latin word texere, "to weave.") An arrange-
ment of similar cells and fibers, forming a distinct structure, and
entering as such into the formation of an organ or organism.
Tonicity. The condition of normal tone or tension of organs; a
state of tone.
Tonus. The normal state of tension of a part or of the body.
Trabecula (pi. se). (From the Latin word trabecula, "a small
beam.") Any one of the fibrous bands extending from the capsule
into the interior of an organ.
Transitional. Denoting a change from one shape to another.
Trapezium (bone). (Named after the resemblance it bears to a
trapezium; shaped like an irregular four-sided figure.) The first
bone of the second row of the wrist.
Trapezius (muscle). Resembles a trapezium in shape.
Trapezoid (bone). Resembles a trapezoid a four-sided geometric
figure having two parallel and two diverging sides.
Triceps (muscle). Three-headed.
Tricuspid. Having three cusps or points.
Trochanters. The processes on the upper extremity of the femur.
Trochlear. Pertaining to or having the nature of a pulley.
Trophic. (From the Greek word meaning nourishment.) Pertaining
to nutrition. Trophic centre, a collection of ganglion cells regulating
the nutrition of a nerve, and thus through the latter the part it
Tuber Cinereum. A tract of gray matter at the base of the cere-
brum, extending from the optic chiasm to the corpora mammillaria, and
forming part of the floor of the third ventricle.
Tuberculum or Tubercle. (From the Latin word tuberculum, "a
tubercle.") A small nodule.' A rounded prominence on a bone.
Tuberosity. (From the Latin word tuber, "a swelling.") A pro-
tuberance on a bone.
Tubular. From the Latin word tubulus, a dim. of tubus, "a tube.")
Shaped like a tube. Pertaining to a tube.
Tubule. From the Latin word tubulus, "a small tube."
Tunica. (From the Latin word tunica, " tunic.") A coat or mem-
Tunica Adyentitia. The outer coat of an artery or vein.
Tunica Intima. The inner coat of an artery or vein.
Tunica Media. The middle coat of an artery or vein.
Tympanic (membrane). Pertaining to the tympanum.
Tympanum. (From the Greek word meaning "a drum.") The
Ulna (bone). (From the Latin word ulna, "a cubit.") The bone
on the inner side of the forearm.
Unciform (bone). (From the Latin word uncus, "a hook;" forma,
"form.") Hook-shaped. A hook-shaped bone in the second row of
Unipolar. (From the Latin words imus, "one;" polus, "a pole.")
Having but one pole or process. As a unipolar nerve cell.
Urea. The chief nitrogenous constituent of the urine, and principal
end-product of tissue metabolism.
Uriniferous (tubules). (From the Latin words urina, "urine;" ferre,
"to bea;\") The tubules which carry or convey urine from the kidney
substance to the pyramids of the kidney.
Uvula. (From the Latin word uvula, from the dim. of uva, "a
grape.") The cone-shaped appendage hanging from the free edge of
the soft palate.
Vagina. (From the Latin word vagina, "a sheath.") 1. A sheath.
2. The musculomernbranous canal extending from the vulval opening
to the mouth of the cervix of the uterus (ostium externum), ensheathing
the latter and the penis (male) during coitus. (See Coitus.)
Vaginal. 1. Pertaining to or of the nature of a sheath. 2. Relating
to the vagina.
Valvulae Conniventes. The small transverse folds of mucous mem-
brane of the small intestine.
Vasa Brevia. The short vessels. The small branches of the splenic
artery which pass to the fundus of the stomach.
Vasoconstrictor (nerves). (From the Latin words vas, "vessel;"
constringere, "to constrict.") Nerves which when stimulated cause
a contraction of the bloodvessels.
Vasodilator. (From the Latin words vas, "a vessel;" dilator, "a
dilator.") Nerves which when stimulated cause a dilatation of the
Vasomotor. (From the Latin words vas, "a vessel;" motor, from
movere, "to move." Regulating the tension of the bloodvessels.
Venae Cavae. (Literally, the hollow veins.) The two large veins
that open into the right auricle of the heart.
Venae Comites. (Accompanying veins.) Veins that accompany an
artery in its course.
Venae Cordis Minimi. The smallest veins of the heart.
Ventral. (From the Latin word venter, "belly.") Pertaining to
the belly. Or used in meaning in front, as ventral aspect.
Ventricle. A small cavity or pouch. (From the Latin ventriculus,
a dim. of venter, "a belly.")
Venule. A small vein.
Vermiform (appendix). (From the Latin word vermis, "a worm;"
forma, "form.") Worm-shaped appendix.
Vernix Caseosa. (A cheesy varnish.) The sebaceous deposit
covering the surface of the fetus. Seen on delivery.
Vertebra. (From the Latin word vertere, "to turn." A single bone
of the spinal column.
Vertebral. Referring to or characteristic of the vertebra.
Vertex. (That which turns or revolves about itself, from the Latin
word vertere, "to turn.") The crown or top of the head or skull.
Vesica Urinaris. The urinary bladder.
ViUus (pi. villi). (From the Latin word, "a tuft of hair.") The
minute club-shaped projections from the mucous membrane of the
small intestine, consisting of a lacteal vessel, an arteriole, and a venule,
enclosed in a layer of epithelial cells.
Virgin. A woman who has never had sexual intercourse.
Viscera Plural of viscus, meaning the organs of the abdomen, etc.
Visceral. Relating to viscera, the stomach, liver, etc.
Vitreous (humor). (From the Latin word vitreus, from vitrum,
"glass.") The transparent, jelly-like substance filling the posterior
chamber of the eye.
Volatile. (From the Latin word volatilis, from volare, "to fly.")
Passing into vapors at ordinary temperatures; evaporating.
Voluntary. Under the control of the will. Voluntary muscles, etc.