| PIRS | plasma immunoreactive secretion |
|---|---|
| PS | pacemaker syndrome; paired stimulation; paradoxical sleep; paraspinal; parasympathetic; Parkinson sy... |
| PTHS | parathyroid hormone secretion [rate] |
| Se | secretion; selenium |
| SIADH | syndrome of inappropriate secretion of antidiuretic hormone |
| internal carotid nerve | <anatomy, nerve> The cephalic arterial ramus conveying postsynaptic sympathetic fibres from the superior cervical ganglion to the internal carotid artery to form the internal carotid plexus. Synonym: nervus caroticus internus. (05 Mar 2000) |
|---|---|
| internal carotid (nervous) plexus | An autonomic plexus surrounding the internal carotid artery in the carotid canal and cavernous sinus, and sending branches to the tympanic plexus, sphenopalatine ganglion, abducens and oculomotor nerves, the cerebral vessels, and the ciliary ganglion. Synonym: internal carotid venous plexus. (05 Mar 2000) |
| internal carotid venous plexus | A venous network around the internal carotid artery in the carotid canal of the temporal bone, connecting with the cavernous sinus and internal jugular vein. Synonym: plexus venosus caroticus internus, internal carotid (nervous) plexus, plexus caroticus internus. (05 Mar 2000) |
| internal cephalic version | Version performed by means of one hand within the vagina. See: cephalic version. (05 Mar 2000) |
| internal cerebral veins | Paired veins passing caudally near the midline in the tela choroidea of the third ventricle, formed by the union of the choroid vein, thalamostriate (terminal) vein, and vein of septum pellucidum, and uniting caudally so as to form the great cerebral vein. Synonym: venae cerebri internae, veins of Galen. (05 Mar 2000) |
| internal collateral ligament of the wrist | A ligament that passes from the styloid process of the ulna to the pisiform and triquetrum. Synonym: ligamentum collaterale carpi ulnare, internal collateral ligament of the wrist, medial ligament of wrist. (05 Mar 2000) |
| internal conjugate | Distance from the promontory of the sacrum to the upper posterior edge of the pubic symphysis. Synonym: anteroposterior diameter of the pelvic inlet, conjugata vera, conjugate axis, conjugate diameter of pelvic inlet, diameter mediana, internal conjugate, true conjugate. (05 Mar 2000) |
| internal conversion electron | An electron, similar to an Auger electron, released from one of the electron orbits of the atom upon activation by a gamma-ray from that atom's nucleus; the electron has kinetic energy equal to the net energy transition of the disintegration. (05 Mar 2000) |
| internal decompression | Removal of intracranial tissue, usually tumour or brain tissue. To relieve pressure. (05 Mar 2000) |
| internal ear | internal ear |
| internal energy | <chemistry> A property of a system that can be changed by a flow of work, heat or both, it is represented by the symbol E (E represents the change in internal energy of a system) and is given in units of energy (Joules). (09 Jan 1998) |
| internal-external control | A general principle that man's attempts to control his personal environment are influenced by internal or external factors. (12 Dec 1998) |
| internal female genital organs | The internal feminine genital organs, the ovaries, uterine tubes, uterus, and vagina. Synonym: organa genitalia feminina interna. (05 Mar 2000) |
| internal fistula | A fistula between hollow viscera. (05 Mar 2000) |
| internal fixation | The use of internal metal plates, screws or rods to stabilise bone fragments. A procedure used to correct serious orthopaedic bone fractures that cannot be stabilised by casting or splinting. See: external fixation. (27 Sep 1997) |