Theglomeruli are well developed and appear spherical form. The glomerulli is well vascularised. The arrangement of glomeruli is on theperipheral part as well as deeper part of the lobule. The visceral layer abuts around the capillaryplexus and shows irregular cells with prominent nucleus.
The parietal layer shows flattened cellssupported by Periodic acid – Schiff’s (PAS)positive basement membrane.The proximalconvoluted tubules (PCTs) presented similar structures of the mammalian type.The tubules are seen surrounding the glomerulus.
The deeper part of theproximal tubules in the medullary region is surrounded by lymphoid tissue. Thesections of proximal tubules appear round and oval. The lumen is wider and shows characteristicbrush border. The cells are pyramidalshape with centrally placed round nucleus. The cytoplasm is acidophilic and nodistinct granules are observed. The pars recta of the proximal tubule are seenin the peripheral part of the lobule as well as in the deeper part of thelobule.
The lumen is smaller and islined by columnar cells with less brush border. These tubules are surrounded bylymphoid tissues. The collecting ducts are seen in the superficial and the medullarypart of the lobule shows collecting duct in ring or clump form around the thinlimbs of loop of Henle. The collectingducts are lined with tall columnar cells and shows cytoplasmic processes. Development of AVIAN Kidneythe excretory system of chick is in accordancewith other amniotes and consists of three separate parts the pronephros,mesonephros and metanephros. These parts develop in the order named and firsttwo have largely disappeared by the close of embryonic life and only the last remainsfunctional as the permanent excretory organ of adult.
Avian LiverThe livercomprises of two separate lobes (Right and Left) which are connected ventrallyby two folds of peritoneum.The lobes are situated at the floor of the abdominalcavity. As the diaphragm is rudimentary the cranial ends of the lobes are veryclose to heart. The parietal surfaces are convex and the visceral surface isconcave.
This surface has impression of many viscera along with that ofstomach. Right lobe has a large gall bladder. The hepatocystic duct of theright lobe and the hepato enteric duct of the left lobe open into the distalpart of ascending limb of the duodenum separately. (Purton MD, 1969) Developmentof AVIAN LiverChick liver starts developing from second day. Just at posterior limit offoregut behind the pharyngeal region, there appear two slight antero- ventrallydirected evaginations of the endoderm whose development is said to be depend oncontact with the veins in this region. These diverticula are not of coursesuspended in space but pushed forward into mass of the splanchnic mesodermwhich unites the gut and ductus venosus in this vicinity. One of thediverticula 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 unionof vitelline veins while other at this period is barely distinguishable.
Thesetwo diverticula represent the rudiments of liver. These diverticula growsomewhat forward and both also branch profusely. At the same time capillariesfrom the ductus venosus begin to develop among the interstices of theseanastomosing branches; this is beginning of the main body of liver.
(Romanoff AL, 1960) SELECTION OF DRUGS EMPLOYED IN THE STUDYIn recent years many drugs have been removedfrom the market because of adverse side-effects. Sandostene, an antihistamine,damaged blood cells; and Flexin, a muscle relaxant, resulted in extensive liverdamage. These findings prompted a study (Fite1965) of the effects of some drugs on chick embryo development.
More than 50% of pregnant womentake prescription or nonprescription (over-the-counter) drugs or consumesocialdrugs (like tobacco and alcohol) or illicit drugs at some time duringpregnancy, and use of drugs during pregnancy is increasing (Porter, 2004).It has been reported that about8% of pregnant women require medicationowing to several chronic diseases and pregnancy related complications. (Sharma et al, 2006)A study in 2001 in United Statesfound that there was not enough information about the risk or safety of morethan 90% medications consumed during pregnancy that were approved by FDA in theduration from 1980 to 2000.
(Andrade et al, 2004) This makes itdifficult for women and health care providers to determine whether to prescribedrugs during pregnancy or not. So three out of commonlydrugs used by gravid ladies were selected to carry out this experimental study.