LIGAMENT (L. _ligo_, to bind). A membrane of a flexible but compact texture, which connects the articular surfaces of bones and cartilages; and sometimes protects the joints by a capsular envelope. LINGUA (L. _lingo_, to lick). The tongue; the organ of taste and speech. LIVER. The largest glandular apparatus in the body, the office of which is to secrete the bile. LUMBI. The loins; the inferior part of the back; whence _Lumbar_, the designation of nerves, arteries, veins, &c., belonging to the region of the loins. LUNGS. The organs of respiration. LUXATION (L. _luxo_, to put out of joint). Dislocation; or the removal of the articular surface of bones out of their proper situation. LYMPH (L. _lympha_, water). A colorless liquid which circulates in the lymphatics. LYMPHATICS (L. _lympha_, water). Minute tubes which pervade every part of the body, which they _absorb_, or take up, in the form of _lymph_. M MAGNESIUM. A metal having the color and lustre of silver. MASSETER (Gr. to chew). A muscle which assists in chewing. MASTOID (Gr. a breast). Shaped like the breast or nipple; as applied to a _process_, and a _foramen_ of the temporal bone. MEATUS (L. _meo_, to pass, to flow). Literally, a passage. MEDULLA. Marrow; a kind of fixed oil, occupying the cavities of bones. MEDULLA OBLONGATA. The upper enlarged portion of the spinal cord. MEDULLA SPINALIS. The spinal marrow or cord. MEDULLARY. The designation of the _white_ substance of the brain. MESENTERY (Gr. between the bowels). The membrane which connects the small intestines and the posterior wall of the abdomen. META-CARPUS (Gr. after, the wrist). That part of the hand which is situated between the carpus and the fingers. META-TARSUS. That part of the foot which is situated between the tarsus and the toes. MIDRIFF. _Diaphragm._ The muscle which divides the body into the thorax and the abdomen. MITRAL VALVES (L. _mitra_, a mitre). The name of two valves which guard the left ventricle of the heart. MOLAR (L. _mola_, a mill-stone). The double or grinding teeth. Those with two fangs are called bicuspid, or false molars. MOTOR (L. _moveo_, to move). A mover; a part whose function is _motion_. MUCUS. The liquid secreted by the mucous surfaces, as of the nostrils, intended as a protection to the parts exposed to external influences. N NARCOTICS (Gr. stupor). Medicines which induce sleep or stupor, as opiates. NASUS. The nose, or organ of smell; whence _nasal_, belonging to the nose. NERVES (L. _nervus_, a string). White cords arising from the brain or the spinal marrow, and distributed to every part of the system. NEURON (Gr.) A nerve; a cord arising from the brain or spinal marrow. Whence _Neurilemma_, the sheath of a nerve; and _Neurology_, the doctrine of the nerves.