| OPLL | ossification of posterior longitudinal ligament |
|---|---|
| PLL | peripheral light loss; phase-locked loop; poly-L-lysine; pressure length loop; posterior longitudina... |
| riMLF | rostral interstitial median longitudinal fasciculus |
| T1 | longitudinal relaxation time |
| T1 | spin-lattice or longitudinal relaxation time; tricuspid first sound |
| longitudinal pontine bundles | The massive bundles of corticofugal fibres passing longitudinally through the ventral part of pons; they are composed of corticopontine, corticobulbar, and corticospinal fibres. Synonym: fasciculi longitudinales pontis, longitudinal pontine bundles. (05 Mar 2000) |
|---|---|
| longitudinal pontine fasciculi | The massive bundles of corticofugal fibres passing longitudinally through the ventral part of pons; they are composed of corticopontine, corticobulbar, and corticospinal fibres. Synonym: fasciculi longitudinales pontis, longitudinal pontine bundles. (05 Mar 2000) |
| longitudinal relaxation | In nuclear magnetic resonance, the return of the magnetic dipoles of the hydrogen nuclei (magnetization vector) to equilibrium parallel to the magnetic field, after they have been flipped 90 |
| longitudinal section | A section that is cut along the long axis of a structure. The opposite is a cross-section. (12 Dec 1998) |
| longitudinal sinus | See: inferior sagittal sinus, superior sagittal sinus. Longitudinal vertebral venous sinus, large, plexiform veins forming portions of the anterior internal vertebral venous plexus lying on the posterior surfaces of the vertebral bodies on either side of the posterior longitudinal ligament. Synonym: sinus vertebrales longitudinales. Luschka's sinus, venous sinus in the petrosquamous suture. (05 Mar 2000) |
| longitudinal studies | Studies in which variables relating to an individual or group of individuals are assessed over a period of time. (12 Dec 1998) |
| longitudinal study | <epidemiology> A study taking place over time. If individuals are followed, this is a longitudinal cohort study. If individuals are not followed, but classes (usually age classes) are restudied, this is a longitudinal cross-sectional study. The converse of a horizontal study. (05 Dec 1998) |
| longitudinal sulcus of heart | See: anterior interventricular groove, posterior interventricular groove. (05 Mar 2000) |
| longitudinal wave | <physics> Waves where the variation of the field is partially or totally in the direction of propagation (parallel to wavennumber, k [a vector]). Examples include sound waves and Langmuir waves. Contrasted with transverse waves, where the variation is perpendicular to the direction of propagation, such as light waves. (13 Nov 1997) |
| abdominal part of thoracic duct | The part of the thoracic duct between the cisterna chyli and the aortic hiatus of the diaphragm. Synonym: pars abdominalis ductus thoracici. (05 Mar 2000) |
| accessory pancreatic duct | The excretory duct of the head of the pancreas, one branch of which joins the pancreatic duct, the other opening independently into the duodenum at the lesser duodenal papilla. Synonym: ductus pancreaticus accessorius, Bernard's canal, Bernard's duct, ductus dorsopancreaticus, Santorini's canal, Santorini's duct. (05 Mar 2000) |
| adenoma, bile duct | A benign tumour of the intrahepatic bile ducts. (12 Dec 1998) |
| alveolar duct | The part of the respiratory passages distal to the respiratory bronchiole; from it arise alveolar sacs and alveoli, the smallest of the intralobular duct's in the mammary gland, into which the secretory alveoli open. Synonym: ductulus alveolaris. (05 Mar 2000) |
| alveolar duct emphysema | Emphysema in which the primary involvement is in the alveolar ducts and respiratory bronchioles, as opposed to panacinar emphysema. (05 Mar 2000) |
| amniotic duct | The transitory opening between the seroamniotic folds in birds just before they fuse to form the seroamniotic raphe. (05 Mar 2000) |