sacrum: Latin os sacrum = sacred, via Greek hieron osteon = sacred bone. Called so either because the sacrum was the part of an animal offered in sacrifice or because of the belief that the soul of the man resides there. A different origin is suggested by an alternate translation of the heron, which can also mean Ôstrong,' and that the Latin stems from a mistranslation of Galen, who was calling it 'the strong bone.'
sagittal: adjective, Latin sagitta = arrow, because the sagittal suture is notched posteriorly, like an arrow, by the lambdoid sutures.
salpinx: Greek = trumpet; hence, the uterine or auditory tube, each of which is trumpet-shaped.
saphenous: adjective, Greek saphenes = obviously visible. The saphenous veins become very apparent when varicose.
sartorius: Latin = tailor; hence, sartorius muscles, which produce the posture in which tailors once worked, squatting on the floor.
scala: Latin = stairs; hence the parallel spiral passages which wind up to, or down from, the cupula of the bony cochlea.
scalene: adjective, Greek skalenos = uneven, hence a triangle with unequal sides, an apt description of the shape of scalenus anterior and scalenus medius muscles.
scalenus: adjective, Greek skalenos = uneven, hence a triangle with unequal sides, an apt description of the shape of scalenus anterior and scalenus medius muscles.
scaphoid: adjective, Greek skaphe = skiff, and eidos = shape or form; hence the carpal which is hollowed out on its distal surface for the head of the capitate; also the fossa occupied by tensor veli palatini muscle.
scapula: Greek skapto = I dig, because of the resemblance to a spade.
sciatic: adjective, Greek ischion = hip-joint. Ischiadikos meant pertaining to the ischium or hip - later changed to sciatic. (The ischium earns its name because it forms > 2/5 of the acetabulum, whereas the ilium contributes < 2/5, and the pubis only 1/5). The sciatic nerve lies on the ischium.
sclera: Greek skleros = hard; hence the tough, outer layer of the eyeball; adjective - scleral.
sclerotome: Greek skleros = hard, and tome = a cutting.
scoliosis: Greek skolios = crooked or curve, and -osis = condition, hence, the lateral curvature of the spine.
scrotum: possibly derived from Latin scorteus = leather; adjective - scrotal.
secrete: Latin secretus = separated; hence, to produce a chemical substance by glandular activity - adjective, secretory; noun, secretion.
stria: Latin = furrow, applied to a streak or stripe.
striatum: adjective, Latin striatus = furrowed; hence, corpus striatum, the caudate and lentiform nuclei connected by grey strands which traverse the internal capsule, giving the strands a striated appearance.
stroma: Greek = bed or mattress, deep to the covers; hence, the supporting framework of an organ, as distinct from its special parenchyma.
styloid: adjective, Greek stylos = an instrument for writing, and eidos = shape or form; hence a pen- or pencil-like structure.
subclavian: Latin sub = under or below, and clavis = a key, hence under the clavicle.
sustentaculum: Latin = a support, which sustains; sustentaculum tali - the ledge on the calcaneus supporting part of the talus.
suture: Latin sutura = a seam; the fibrous joints between cranial bones.
sympathetic: Greek syn = with, and pathos = feeling; hence, the peripheral part of the autonomic nervous system which arises in the thoracolumbar region of the spinal cord and communicates with other nerves.
symphysis: Greek syn = with, and physis = growth; hence a joint where union between the bones is by fibrocartilage - used for median joints. (Symphysis of the mandible is exceptional, the 2 halves fusing before the age of 2).
synapse: Greek syn = with, and aptein = to join; hence, the zone through which an impulse passes from one neuron to another.
synchondrosis: Greek syn = with, and chondros = cartilage; hence, the union of 2 bones by cartilage.
syncytium: Greek syn = with, and kytos = cell, hence a multinucleate mass of protoplasm, formed by the merging of cells.
syndesmosis: Greek syn = with, and desmos = a band; hence, the union of 2 bones by fibrous tissue.
syndrome: Greek syn = with, and dromos = running; hence, a group of signs and symptoms which is characteristic of a certain pathology.
synergist: Greek syn = with, and ergon = work; hence a muscle which cooperates with others in producing a given movement.
synovia: Greek syn = with, and ovum = egg; hence the fluid in freely movable joints resembling egg-white; adjective, synovial.
synovial: adjective, Greek syn = with, and ovum = egg; hence pertaining to the fluid in freely movable joints resembling egg-white.
systole: Greek = contraction; hence the contraction of cardiac muscle.