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.