Lumen Sentence Examples
Externally, the nephridium opens by a straight part of the tube, which is often very wide, and here the intracellular lumen becomes intercellular.
In Polynoe the nephridia are short tubes with a slightly folded funnel whose lumen is intercellular, and this intercellular lumen is characteristic of the Polychaetes as contrasted with leeches and Oligochaetes.
On Easter Eve new fire is made 3 with a flint and steel, and blessed; from this three candles are lighted, the lumen Christi, and from these again the Paschal Candle.
Nephridia generally paired, often very numerous in each segment, in the form of long, much-coiled tubes with intracellular lumen.
The nephridia in this group are invariably coiled tubes with an intracellular lumen and nearly invariably open into the coelom by a funnel.Advertisement
In one family, the Ptychoderidae, the medullary tube of the collar is connected at intermediate points with the epidermis by means of a variable number of unpaired outgrowths from its dorsal wall, generally containing an axial lumen derived from and in continuity with the central canal.
They consist of a pair of tubules with an intracellular lumen running up the sides of the body, at times merely sinuous, at others considerably convoluted.
Close to them is the remarkable dart-sac ps, a thick-walled sac, in the lumen of which a crystalline four-fluted rod or dart consisting of carbonate of lime is found.
At the end of each twig is a membrane pierced by pores, and a number of cilia depend into the lumen of the tube; these cilia maintain a constant motion.
Although an integral portion of the gut, it has ceased to assist in alimentation, its epithelium undergoes vacuolar differentiation and hypertrophy, and its lumen becomes more or less vestigial.Advertisement
The small opening among the fimbriae by which the tube communicates with the peritoneal cavity is known as the ostium abdominale, and from this the lumen of the tube runs from four to four and a half inches, until it opens into the cavity of the uterus by an extremely small opening.
About the fifth week of human embryonic life the tunica albuginea appears in the male, from which septa grow to divide the testis into lobules, while the epithelial cords form the seminiferous tubes, though these do not gain a lumen until just before puberty.
In many cases the swollen cell-walls serve as reserves, and sometimes the substance is so thickly deposited in strata as to obliterate the lumen, and the hyphae become nodular (Polyporus sacer, P. rhinoceros, Lentinus Woermanni).
Into the former the ovaries project, though the lumen of the lateral body-cavity is quite shut off from the lumina of the ovaries or uteri.
In his Synopsis physicae ad lumen divinum reformatae he gives a physical theory of his own, said to be taken from the book of Genesis.Advertisement
The secondary wood of Ephedra consists of tracheids, vessels and parenchyma; the vessels are characterized by their wide lumen and by the large simple or slightly-bordered pits on their oblique end-walls.
Some of the blood vessels have collapsed post mortem and the gut lumen is often distended with gas.
In asthma, the bronchial epithelium is often damaged, with shedding of the columnar cells into the airway lumen.
A benchtop model was constructed reproducing the nitrite chemistry occurring within the lumen of the upper gastrointestinal tract where saliva encounters acidic gastric juice.
The transit peptide is very similar in structure to a family of nuclear proteins imported into the thylakoid lumen.Advertisement
The desquamation of such cells into the intestinal lumen leads to the excretion of the copper.
The space within the er is called the ER lumen.
Next, pass the needle from inside to out and back in to the vessel lumen.
In bowel obstruction fluid is secreted into the bowel lumen.
Therefore a 3600 lumen projector is twice as bright visually as a 900, not 1800 as you would expect.Advertisement
In its earlier conception, this view embraced as homologous organs (so far as the present group is concerned) not only the nephridia of Oligochaeta and Hirudinea, which are obviously closely similar, but the wide tubes with an intercellular lumen and large funnels of certain Polychaeta, and (though with less assurance) the gonad ducts in Oligochaeta and Hirudinea.
There are no renal organs with a wide intercellular lumen, such as occur in the Polychaeta, nor is there ever any permanent association between nephridia and ducts connected with the evacuation of the generative products, such as occur in Alciope, Saccocirrus, &c. In these points the Oligochaeta agree with the Hirudinea.
Externally, the nephridium opens by a vesicle, as in many Oligochaetes whose lumen is intercellular.
The inner surface of the intestinal caeca is ciliated, the caeca themselves are some times - especially in the UT hindermost portion of the body - of a considerably smaller lumen than the intermediate genital spaces; sometimes, however, the reverse is the case, and in both cases it is the smaller lumen that appears enclosed between and suspended by the transverse fibres constituting the muscular dissepiments above mentioned.
When examined with the microscope, by means of the usual section method, they are seen to consist of a labyrinthine tube lined with peculiar cells, each cell having a deep vertically striated border on the surface farthest from the lumen, as is seen in the cells of some renal organs.
The polypeptide chains synthesized by the ribosomes bound to the rough E.R. enter the endoplasmic reticulum lumen.
These proteins are extruded into the lumen of the E.R. as they are synthesized by ribosomes bound to docking proteins on the cytoplasmic surface.
They act by attracting and holding water in the intestinal lumen, and may produce a watery stool.
In newborns, congenital duodenal obstruction can occur when the duodenal channel (duodenal lumen) is not correctly formed (recanalized) during fetal development.
The duodenum may have a membrane reducing the channel size (lumen), or two blind pouches instead of one duodenal channel, or a gap or flap of tissue may be present.
Duodenal atresia can occur with other conditions such as a narrowing of the duodenal lumen (duodenal stenosis) or twisting of the duodenum around itself (duodenal volvulus).
Malrotation may also involve the presence of Ladd's bands, abnormal folds or bands of tissue under tension across the lumen of the duodenum.
It involves opening the duodenum channel along its length from the stomach to the next portion of intestine, correcting the duodenal lumen end to end (gastrojejunal anastomosis) so that it is a fully open channel.
Appendicitis is usually caused by a blockage of the inside of the appendix, which is called the lumen.
Most often, the lumen is blocked by fecal material.
In addition, genetics may play a role in appendicitis; some children may inherit genes that make them more susceptible to blockage of the appendiceal lumen.
Essentially, a nephridium is a tube, generally very long and much folded upon itself, composed of a string of cells placed end to end in which the continuous lumen is excavated.
Frequently the lumen is branched and may form a complicated anastomosing network in these cells.
Rarely the nephridium does not communicate with the coelom; in such cases the nephridium ends in a single cell, like the "flame cell" of a Platyhelminth worm, in which there is a lumen blocked at the coelomic end by a tuft of fine cilia projecting into the lumen.
The Polychaeta, however, present us with another form of nephridium seen, for example, in Arenicola, where a large funnel leads into a short and wide excretory tube whose lumen is intercellular.
In all these cases we have a duct which has a usually wide, always intercellular, lumen, generally, if not always, ciliated, which opens directly into the coelom on the one hand and on to the exterior of the body on the other.
Nephridia always paired, rarely (Pontobdella) forming a network communicating from segment to segment; lumen of nephridia always intracellular, funnels pervious or impervious.
Two layers are specially obvious in its walls - the inner layer bordering the lumen being composed of smaller ciliated cells, the outer thicker one containing numerous granular cells and having a more glandular character.
Fibre-like hyphae with the lumen almost obliterated by the thick walls occur in mycelial cords (Merulius).