| haemorrhoids, internal | Haemorrhoids that occur above the dentate line in the anal canal which separates two types of anal skin. The skin above the dentate line is not sensitive to pain. Internal haemorrhoids, being above the dentate line, are therefore usually painless. They can cause bleeding or they may push out of (prolapse) the anal opening when they become quite large. (07 Jan 1998) |
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| sternal branches of internal thoracic artery | <anatomy, artery> Branches of internal thoracic artery which pass medially to supply the transversus thoracis muscle and posterior sternum. Synonym: rami sternales arteriae thoracicae internae, sternal arteries. (05 Mar 2000) |
| sublenticular limb of internal capsule | The part of the internal capsule below the caudal third of the lentiform nucleus that contains the auditory radiation as well as that part of the optic radiation representing the upper part of the contralateral half of the binocular visual field. Synonym: pars sublentiformis capsulae internae, sublenticular limb of internal capsule. (05 Mar 2000) |
| sublenticular part of internal capsule | The part of the internal capsule below the caudal third of the lentiform nucleus that contains the auditory radiation as well as that part of the optic radiation representing the upper part of the contralateral half of the binocular visual field. Synonym: pars sublentiformis capsulae internae, sublenticular limb of internal capsule. (05 Mar 2000) |
| superior internal parietal artery | <anatomy, artery> The largest cortical branch of the pericallosal artery supplying the medial and superolateral surface of the parietal lobe posterior to the paracentral lobule; rarely does it extend to supply part of the occipital lobe. Synonym: arteria parieto-occipitalis, superior internal parietal artery. (05 Mar 2000) |
| 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) |