| dark-ground illumination | dark-field illumination |
|---|---|
| dark reaction | <biochemistry, plant biology> The reactions in photosynthesis that occur after NADPH and ATP production and that take place in the stroma of the chloroplast. By means of the reaction, carbon dioxide is incorporated into carbohydrate. (18 Nov 1997) |
| dark t2 lesion | <radiology> (short T2), acute haemorrhage (deoxyHb), haemosiderin, physiologic iron (basal ganglia, etc.), mucinous lesions (?) most abnormalities have long T1 and T2 (dark/bright). Compare: bright T1 lesion. (07 Mar 2000) |
| absorptive cells of intestine | Cell's on the surface of villi of the small intestine and the luminal surface of the large intestine that are characterised by having microvilli on their free surface. (05 Mar 2000) |
| air cells | Air-containing spaces in the skull. See: pulmonary alveolus. (05 Mar 2000) |
| air cells of auditory tube | Occasional small air cells in the inferior wall of the auditory tube, near the tympanic orifice, communicating with the tympanic cavity. Synonym: cellulae pneumaticae tubae auditivae, air cells of auditory tube. (05 Mar 2000) |
| Alpha cells | Alpha cell's of pancreas or of anterior lobe of hypophysis. (05 Mar 2000) |
| alpha cells of anterior lobe of hypophysis | Acidophil cell's that constitute about 35% of the cell's of the anterior lobe. There are two varieties: one that elaborates somatotropin, another that elaborates prolactin. (05 Mar 2000) |
| alpha cells of pancreas | Cell's of the islets of Langerhans that secrete glucagon. (05 Mar 2000) |
| amniogenic cells | Cell's from which the amnion develops. (05 Mar 2000) |
| anabiotic cells | Cell's that are capable of resuscitation after apparent death; the existence of anabiotic tumour cell's is postulated to explain the recurrence of a cancer after a very long symptomless period following operation. (05 Mar 2000) |
| angioblastic cells | Those cell's in the early embryo from which primitive blood cell's and endothelium develop. (05 Mar 2000) |
| anterior cells | The anterior group of air cells of the ethmoidal sinus's; each sinus communicates with the middle meatus of the nasal cavity. Synonym: sinus ethmoidales anteriores, anterior cells, anterior sinuses, cellulae anteriores. (05 Mar 2000) |
| anterior ethmoidal air cells | The anterior group of air cells of the ethmoidal sinus's; each sinus communicates with the middle meatus of the nasal cavity. Synonym: sinus ethmoidales anteriores, anterior cells, anterior sinuses, cellulae anteriores. (05 Mar 2000) |
| anterior horn cells | Motor neurons in the anterior (ventral) horn of the spinal cord which project to skeletal muscles. (12 Dec 1998) |