| primary cell wall | <plant biology> A plant cell wall that is still able to expand, permitting cell growth. Growth is normally prevented when a secondary wall has formed. Primary cell walls contain more pectin than secondary walls and no lignin is present until a secondary wall has formed on top of them. (06 Mar 1998) |
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| helicoidal cell wall | Type of plant cell wall in which each wall layer contains parallel microfibrils, but in which the orientation of the microfibrils changes by a fixed angle from one layer to the next. Gives a characteristic herringbone pattern in transmission electron microscopy. A similar architecture of fibrillar material is seen in some insect exoskeletons. (18 Nov 1997) |
| secondary wall | <plant biology> The part of the plant cell wall which is laid down on top of the primary wall after the wall has ceased to increase in surface area. Only occurs in certain cell types, for example tracheids, vessel elements and sclerenchyma. Differs from the primary wall both in composition and structure and is often diagnostic for a particular cell type. (18 Nov 1997) |
| hollow wall | A condition of the hoof wall in the toe region of horses, characterised by loss of substance and change in character of the horn, most often as a sequela of mild chronic laminitis. Synonym: dystrophia ungulae, hollow wall. (05 Mar 2000) |
| pulpal wall | One of the wall's of the pulp cavity, the wall of a cavity preparation adjacent to the pulp space; e.g., mesial pulpal wall. (05 Mar 2000) |
| hyaline degeneration of the elastic tissue of the arterial wall | Seen during involution of the uterus. (05 Mar 2000) |
| splanchnic wall | The wall of one of the viscera or the splanchnopleure from which it is formed. (05 Mar 2000) |
| sporulation-specific cell wall hydrolase | <enzyme> From bacillus subtilis; 255-amino acid protein mw 27.146 kD; hydrolyzes both vegetative cell walls and spore peptidoglycan genbank d14666 Registry number: EC 3.- Synonym: cwlc gene product (26 Jun 1999) |
| superior wall of orbit | Formed by the orbital plate of the frontal bone and the lesser wing of the sphenoid bone, the optic canal opens at its posterior limit; an indentation, the fossa for the lacrimal gland, is located in the anterolateral part of the roof. Synonym: paries superior orbitae, superior wall of orbit. (05 Mar 2000) |
| diffuse gallbladder wall thickening | <radiology> Criterion: gall bladder wall greater than 3 mm may appear thicker due to surrounding ascites, cholecystitis (acute or chronic), non-fasting state, chronic hypoalbuminaemia, hepatitis, congestive heart failure, fat in gall bladder fossa Cf: focal thickening (12 Dec 1998) |
| inferior wall of orbit | The floor of the orbit; the shortest of the four walls of the orbit, sloping upward from the orbital margin; it is comprised of the maxilla and orbital process of the palatine bone. Synonym: paries inferior orbitae, inferior wall of orbit. (05 Mar 2000) |
| inferior wall of tympanic cavity | The floor of the tympanic cavity; a thin plate of bone separating the tympanic cavity from the jugular fossa. Synonym: paries jugularis cavi tympani, fundus tympani, inferior wall of tympanic cavity, jugular wall of middle ear. (05 Mar 2000) |
| tegmental wall of middle ear | The superior wall, or roof, of the tympanic cavity, formed by the tegmen tympani of the temporal bone. Synonym: paries tegmentalis cavi tympani, tegmental wall of middle ear. (05 Mar 2000) |
| thoracic wall | In respiratory physiology, the total system of structures outside the lungs that move as a part of breathing; it includes the rib cage, diaphragm, abdominal wall, and abdominal contents. Synonym: thoracic wall. (05 Mar 2000) |
| enamel wall | In dentistry, the part of the wall of a cavity consisting of enamel. (05 Mar 2000) |