| mIU | milli-international unit; one-thousandth of an international unit |
|---|---|
| MRU | mass radiography unit; minimal reproductive unit |
| PFU | plaque-forming unit; pock-forming unit |
| PICU | pediatric intensive care unit; pulmonary intensive care unit |
| PSU | photosynthetic unit; primary sampling unit |
| inferior internal parietal artery | <anatomy, artery> The last cortical branch of the pericallosal artery; it supplies the inferior part of the precuneus. Synonym: arteria precunealis, inferior internal parietal artery. (05 Mar 2000) |
|---|---|
| internal | <anatomy> Situated or occurring within or on the inside, many anatomical structures formerly called internal are now correctly termed medial. Origin: L. Internus (18 Nov 1997) |
| internal acoustic foramen | The inner opening of the internal acoustic meatus on the posterior surface of the petrous part of the temporal bone. Synonym: porus acusticus internus, internal acoustic foramen, internal acoustic pore, auditory pore, internal auditory foramen, orifice of internal acoustic meatus. (05 Mar 2000) |
| internal acoustic pore | The inner opening of the internal acoustic meatus on the posterior surface of the petrous part of the temporal bone. Synonym: porus acusticus internus, internal acoustic foramen, internal acoustic pore, auditory pore, internal auditory foramen, orifice of internal acoustic meatus. (05 Mar 2000) |
| internal adhesive pericarditis | Extensive adhesion between parietal and visceral layers of the pericardium with partial or complete obliteration of the pericardial cavity. Synonym: internal adhesive pericarditis, synechia pericardii. (05 Mar 2000) |
| internal anal sphincter | <anatomy> A smooth muscle ring, formed by an increase of the circular fibres of the rectum, situated at the upper end of the anal canal, internal to the outer voluntary external anal sphincter. This sphincter is maximally-contracted when the rectal ampulla is at rest -empty or relaxed to accommodate a distending faecal mass. It is inhibited with filling of the ampulla, increased distension and peristalsis. Synonym: musculus sphincter ani internus, internal sphincter muscle of anus. (05 Mar 2000) |
| internal arcuate fibres | <anatomy> Fibres that arise in the cuneate and gracile nuclei, pass in a curving course across the midline of the medulla oblongata, and form the contralateral medial lemniscus. It also designates other fibres such as those of the olivocerebellar tract that arch through the substance of the medulla and form sensory decussation. Synonym: fibrae arcuatae internae. (05 Mar 2000) |
| internal attachment | A frictional or mechanically retained unit used in fixed or removable prosthodontics, consisting of closely fitting male and female parts, an attachment that may be rigid in function or may incorporate a movable stress control unit to reduce the torque on the abutment. Synonym: frictional attachment, internal attachment, key attachment, keyway attachment, parallel attachment, slotted attachment. (05 Mar 2000) |
| internal auditory artery | <anatomy, artery> Internal acoustic meatal branch. A branch of the basilar artery that enters the labyrinth through the internal acoustic meatus. Synonym: arteria labyrinthi, ramus meatus acustici interni, arteria auditiva interna, artery of labyrinth, internal auditory artery. (05 Mar 2000) |
| internal auditory canal | <anatomy> Abnormal if difference in diameter greater than 2 mm, schematic: 7 8-sv anterior posterior 8-c 8-iv, 7 facial nerve (VII), 8-c cochlear division of VIII, 8-sv superior vestibular division, 8-iv inferior vestibular division (12 Dec 1998) |
| internal auditory foramen | The inner opening of the internal acoustic meatus on the posterior surface of the petrous part of the temporal bone. Synonym: porus acusticus internus, internal acoustic foramen, internal acoustic pore, auditory pore, internal auditory foramen, orifice of internal acoustic meatus. (05 Mar 2000) |
| internal auditory meatus | internal acoustic meatus |
| internal auditory veins | One or more veins accompanying the labyrinthine artery; they drain the internal ear, pass out through the internal acoustic meatus, and empty into the transverse sinus or the inferior petrosal sinus. Synonym: venae labyrinthi, internal auditory veins. (05 Mar 2000) |
| internal axis of eye | <anatomy> That part of the optic axis from the midpoint of the posterior surface of the cornea to the anterior surface of the retina opposite the posterior pole. Synonym: axis bulbi internus. (05 Mar 2000) |
| internal base of skull | <anatomy> The interior aspect of the skull base on which the brain rests; the floor of the cranial cavity. See: base of skull. Synonym: basis cranii interna. (05 Mar 2000) |