Aqueduct
L. aqua = water, and ductus = a canal. In Latin the word was spelled aquaeductus, therefore the spelling with an e.
Arachnoid
Gr. arachne = spider, and eidos = resemblance. From this root came the Latin term arachnoides = spider-like. Used to describe the coweb-like membrane covering the brain and spinal cord.
Arenavirus
L. arena = "sand". Viewed in cross-section, arenaviruses contain grainy particles that are ribosomes acquired from their host cells. It is from this characteristic that they acquired the name arena,…
Areola
L. area = a courtyard or space, and diminiutive suffix –ola. A term used in several ways, but especially applied to the pigmented area around the nipple.
Articulation
L. articulus, diminuitive or arthus = joint, and atio = a suffix, originally denoting action.
Atrium
L. atrium = a hall, or an entrance. Used for the upper chamber of the heart.
Auricula
L. Auricula, diminuitive of auris = ear. Used in anatomy of any ear-shaped structure, but applied especially to the appendage of the upper chamber of each side of the heart, because they bear…
Axis
L. axis = axle or pivot. Also refers to the second cervical vertebrae (C2).