| PAR | participating provider; passive avoidance reaction; perennial allergic rhinitis; photosynthetically ... |
|---|---|
| PAS | para aminosalicylate; Parent Attitude Scale; patient administration system; patient appointments and... |
| PAV | percutaneous aortic valvuloplasty; poikiloderma atrophicans vasculare; posterior arch vein; proporti... |
| PBW | posterior bite wing |
| PCD | pacer-cardioverter-defibrillator; papillary collecting duct; paraneoplastic cerebellar degeneration;... |
| posterior cerebral artery | <anatomy, artery> Formed by the bifurcation of the basilar artery; it passes around the cerebral peduncle to reach the medial aspect of the hemisphere; for descriptive purposes it is divided into three parts: 1) the precommunical part (P1 segment of clinical terminology), the part before the junction with the posterior communicating artery, supplying parts of the thalamus, hypothalamus, and midbrain; 2) the postcommunical part (P2), supplying the thalamus, cerebral peduncles, and the choroid plexuses of the lateral and third ventricles; and 3) the terminal or cortical part, supplying the cortex of the temporal (P3) and occipital (P4) lobes. Synonym: arteria cerebri posterior. (05 Mar 2000) |
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| posterior cerebral commissure | A thin band of white matter, crossing from side to side beneath the habenula of the pineal body and over the aditus ad aqueductum cerebri; it is largely composed of fibres interconnecting the left and right pretectal region and related cell groups of the midbrain; dorsally, it marks the junction of the diencephalon and mesencephalon. Synonym: posterior cerebral commissure. (05 Mar 2000) |
| posterior cervical intertransversarii muscles | Origin, lateral part: posterior tubercle of cervical transverse process; medial part: transverse process; insertion, corresponding parts of next superior transverse process; action, abducts cervical vertebrae; nerve supply, lateral part: ventral primary rami of cervical spinal nerves; medial part: dorsal primary rami of cervical spinal nerves. Synonym: musculi intertransversarii posteriores cervicis, posterior cervical intertransverse muscles. (05 Mar 2000) |
| posterior cervical intertransverse muscles | Origin, lateral part: posterior tubercle of cervical transverse process; medial part: transverse process; insertion, corresponding parts of next superior transverse process; action, abducts cervical vertebrae; nerve supply, lateral part: ventral primary rami of cervical spinal nerves; medial part: dorsal primary rami of cervical spinal nerves. Synonym: musculi intertransversarii posteriores cervicis, posterior cervical intertransverse muscles. (05 Mar 2000) |
| posterior chamber of eye | The ringlike space, filled with aqueous humor, between the iris/pupil anteriorly and the lens and ciliary body posteriorly. Synonym: camera posterior bulbi, camera oculi minor, camera oculi posterior. (05 Mar 2000) |
| posterior choroidal artery | <anatomy, artery> One of several choroid branches of the P2 segment of the posterior cerebral artery that supply the choroid plexus of the body of the lateral ventricle and of the third ventricle. Synonym: arteria choroidea posterior. (05 Mar 2000) |
| posterior choroiditis | Disseminated choroiditis restricted to the central choroid. (05 Mar 2000) |
| posterior circumflex humeral artery | <anatomy, artery> Origin, axillary; distribution, muscles and structures of shoulder joint; anastomoses, anterior circumflex humeral, suprascapular, thoracoacromial, and profunda brachii. Synonym: arteria circumflexa humeri posterior, posterior humeral circumflex artery. (05 Mar 2000) |
| posterior column | The pronounced, dorsolaterally oriented ridge of gray matter in each lateral half of the spinal cord, corresponding to the posterior or dorsal horn appearing in transverse sections of the cord. Synonym: columna posterior, dorsal column of spinal cord, posterior column of spinal cord. (05 Mar 2000) |
| posterior column cordotomy | Division of the posterior column of the spinal cord. (05 Mar 2000) |
| posterior column of spinal cord | The pronounced, dorsolaterally oriented ridge of gray matter in each lateral half of the spinal cord, corresponding to the posterior or dorsal horn appearing in transverse sections of the cord. Synonym: columna posterior, dorsal column of spinal cord, posterior column of spinal cord. (05 Mar 2000) |
| posterior communicating artery | <anatomy, artery> Origin, internal carotid; distribution, optic tract, crus cerebri, interpeduncular region, and hippocampal gyrus; anastomoses, with posterior cerebral to form the cerebral arterial circle (circle of Willis). Synonym: arteria communicans posterior. (05 Mar 2000) |
| posterior condyloid foramen | The inconstant opening through the occipital bone posterior to the condyle on each side that transmits the occipital emissary vein. Synonym: canalis condylaris, posterior condyloid foramen. (05 Mar 2000) |
| posterior conjunctival artery | <anatomy, artery> One of a series of branches from the arterial arches of the upper and lower eyelids that supplies the conjunctiva. Synonym: arteria conjunctivalis posterior, conjunctival arteries. (05 Mar 2000) |
| posterior cord of brachial plexus | In the brachial plexus, the bundle of nerve fibres formed by the posterior divisions of the upper, middle and lower trunks which lies posterior to the axillary artery; it gives rise to the upper and lower subscapular and thoracodorsal nerves, terminates by dividing into the axillary, and radial nerves. Synonym: fasciculus posterior plexus brachialis. (05 Mar 2000) |