glomeruli are well developed and appear spherical form. The glomerulli is well vascularised. The arrangement of glomeruli is on the
peripheral part as well as deeper part of the lobule. The visceral layer abuts around the capillary
plexus and shows irregular cells with prominent nucleus. The parietal layer shows flattened cells
supported by Periodic acid – Schiff’s (PAS)
positive basement membrane.
convoluted tubules (PCTs) presented similar structures of the mammalian type.
The tubules are seen surrounding the glomerulus. The deeper part of the
proximal tubules in the medullary region is surrounded by lymphoid tissue. The
sections of proximal tubules appear round and oval. The lumen is wider and shows characteristic
brush border. The cells are pyramidal
shape with centrally placed round nucleus. The cytoplasm is acidophilic and no
distinct granules are observed. The pars recta of the proximal tubule are seen
in the peripheral part of the lobule as well as in the deeper part of the
lobule. The lumen is smaller and is
lined by columnar cells with less brush border. These tubules are surrounded by
lymphoid tissues. The collecting ducts are seen in the superficial and the medullary
part of the lobule shows collecting duct in ring or clump form around the thin
limbs of loop of Henle. The collecting
ducts are lined with tall columnar cells and shows cytoplasmic processes.
Development of AVIAN Kidney
the excretory system of chick is in accordance
with other amniotes and consists of three separate parts the pronephros,
mesonephros and metanephros. These parts develop in the order named and first
two have largely disappeared by the close of embryonic life and only the last remains
functional as the permanent excretory organ of adult.
comprises of two separate lobes (Right and Left) which are connected ventrally
by two folds of peritoneum.The lobes are situated at the floor of the abdominal
cavity. As the diaphragm is rudimentary the cranial ends of the lobes are very
close to heart. The parietal surfaces are convex and the visceral surface is
concave. This surface has impression of many viscera along with that of
stomach. Right lobe has a large gall bladder. The hepatocystic duct of the
right lobe and the hepato enteric duct of the left lobe open into the distal
part of ascending limb of the duodenum separately. (Purton MD, 1969)
of AVIAN Liver
Chick liver starts developing from second day. Just at posterior limit of
foregut behind the pharyngeal region, there appear two slight antero- ventrally
directed evaginations of the endoderm whose development is said to be depend on
contact with the veins in this region. These diverticula are not of course
suspended in space but pushed forward into mass of the splanchnic mesoderm
which unites the gut and ductus venosus in this vicinity. One of the
diverticula is a little in advance in position and in time of appearance too.
It presently pushes forward so as to lie just lie dorsal to the point of union
of vitelline veins while other at this period is barely distinguishable. These
two diverticula represent the rudiments of liver. These diverticula grow
somewhat forward and both also branch profusely. At the same time capillaries
from the ductus venosus begin to develop among the interstices of these
anastomosing branches; this is beginning of the main body of liver. (Romanoff AL, 1960)
SELECTION OF DRUGS EMPLOYED IN THE STUDY
In recent years many drugs have been removed
from the market because of adverse side-effects. Sandostene, an antihistamine,
damaged blood cells; and Flexin, a muscle relaxant, resulted in extensive liver
damage. These findings prompted a study (Fite
1965) of the effects of some drugs on chick embryo development.
More than 50% of pregnant women
take prescription or nonprescription (over-the-counter) drugs or consumesocial
drugs (like tobacco and alcohol) or illicit drugs at some time during
pregnancy, and use of drugs during pregnancy is increasing (Porter, 2004).
It has been reported that about
8% of pregnant women require medication
owing to several chronic diseases and pregnancy related complications. (Sharma et al, 2006)
A study in 2001 in United States
found that there was not enough information about the risk or safety of more
than 90% medications consumed during pregnancy that were approved by FDA in the
duration from 1980 to 2000. (Andrade et al, 2004) This makes it
difficult for women and health care providers to determine whether to prescribe
drugs during pregnancy or not.
So three out of commonly
drugs used by gravid ladies were selected to carry out this experimental study.