| AR | absolute risk; accounts receivable; achievement ratio; actinic reticuloid [syndrome]; active resista... |
|---|---|
| ARAO | angiographic area of right anterior oblique projection |
| ARV | acquired immunodeficiency syndrome-related virus; anterior right ventricle; avian reovirus |
| ASA | acetylsalicylic acid; active systemic anaphylaxis; Adams-Stokes attack; American Society of Anesthes... |
| asc | ascending; anterior subcapsular |
| anterior layer of rectus abdominis sheath | The portion of the rectus sheath that lies anterior to the muscle, consisting in its upper two-thirds of contributions from the aponeuroses of the external and internal oblique muscles, and in its lower third (below the arcuralt line) of contributions from the aponeuroses of all three muscles of the anterolateral abdominal wall. Synonym: lamina anterior vaginae musculi recti abdominis. (05 Mar 2000) |
|---|---|
| anterior ligament of head of fibula | A ligament uniting the anterior part of the head of the fibula to the tibia. Synonym: ligamentum capitis fibulae anterius. (05 Mar 2000) |
| anterior ligament of Helmholtz | See: anterior ligament of malleus. (05 Mar 2000) |
| anterior ligament of malleus | Consists of two portions: Meckel's band, passing from the base of the anterior process to the spine of the sphenoid through the petrotympanic fissure; and the anterior ligament of Helmholtz, extending from the anterior aspect of the neck of the malleus to the anterior boundary of the tympanic notch. Synonym: ligamentum mallei anterius. (05 Mar 2000) |
| anterior limb of internal capsule | The portion of the internal capsule between the head of the caudate nucleus and the putamen; it lies anterior to the genu of the internal capsule. Synonym: crus anterius capsulae internae. (05 Mar 2000) |
| anterior limb of stapes | The anterior of the two delicate curving limbs of the stapes that pass from the head of the bone to the base or footplate. Synonym: crus anterius stapedis, anterior limb of stapes. (05 Mar 2000) |
| anterior limiting layer of cornea | A transparent homogeneous acellular layer, 6 to 9 um thick, lying between the basal lamina of the outer layer of stratified epithelium and the substantia propria of the cornea; considered to be a basement membrane. Synonym: lamina limitans anterior corneae, anterior elastic layer, Bowman's membrane, lamina elastica anterior, limiting layers of cornea. (05 Mar 2000) |
| anterior limiting ring | The periphery of the cornea marking the termination of Descemet's membrane and the anterior border of the trabecular meshwork; an important landmark in gonioscopy. Synonym: Schwalbe's ring. (05 Mar 2000) |
| anterior lingual gland | One of the small mixed glands deeply placed near the apex of the tongue on each side of the frenulum. Synonym: glandula lingualis anterior, apical gland, Bauhin's gland, Blandin's gland, Nuhn's gland. (05 Mar 2000) |
| anterior lip of uterine os | The portion of the vaginal part of the uterine cervix that bounds the ostium anteriorly intervening between the ostium and the anterior vaginal fornix. It is slightly shorter than labium posterius. Synonym: labium anterius ostii uteri. (05 Mar 2000) |
| anterior lobe of hypophysis | An alternate term for adenohypophysis. (05 Mar 2000) |
| anterior longitudinal ligament | <anatomy> The wide fibrous band interconnecting the anterior surfaces of the vertebral bodies. Synonym: lacertus medius, ligamentum longitudinale anterius. (05 Mar 2000) |
| anterior lunate lobule | The part of the superior surface of the cerebellar hemisphere lying rostral to the horizontal fissure, and adjoining the folium of the vermis. Synonym: lobulus semilunaris superior, anterior lunate lobule, crus I. (05 Mar 2000) |
| anterior margin | The ventral or most forward margin of a structure. Synonym: anterior margin, ventral border. (05 Mar 2000) |
| anterior medial malleolar artery | <anatomy, artery> Origin, anterior tibial; distribution, ankle joint and neighboring integument; anastomoses, branches of posterior tibial. Synonym: arteria malleolaris anterior medialis. (05 Mar 2000) |