Anatomical study the choledocho - pancreatico - duodenal junction in man

Twenty - five fresh postmortem human specimens of both sexes were utilized, in this study, for gross and microscopic dissection of the choledocho-pancreatico-duodenal junction. Histological examination of the terminal ducts, at this region, was also performed. The common bile and main pancreatic ducts have been observed to exhibit three patterns of confluences: the short Y - shaped confluence [Pattern I, 52%] with a short common channel [2 - 15 mm], the long Y - shaped confluence [Pattern II, 20%] with a long common channel [> 15 mm] and the V - shaped confluence [Pattern III, 28%] with a very short common channel [< 2 mm]. The main pancreatic duct has been observed to follow a wavy course presenting two differently directed curvatures on its way towards the duodenum. Along its course, the main pancreatic duct is joined by duct tributaries at nearly right angles. The accessory pancreatic duct has been detected in 72% of specimens. A communicating channel between the accessory and main pancreatic ducts has been observed in 48% of specimens. The accessory duct has always joined the duodenum proximal to, and at a more anterior plane than, the main duct. The major duodenal papilla is located within the middle [72%] or lower [28%] thirds of the descending part of the duodenum. It lies at the proximal end of a longitudinal mucous fold [80%], at the middle of this longitudinal fold [12%], or with absence of such a fold [8%]. Transverse mucous folds [2 - 4 in number] are noticed to converge at the longitudinal fold and the papilla. The investigation has also revealed the presence of circumferential folds partially or completely obscuring the major papilla. The minor duodenal papilla is entangled by a mucosal sling, or between two circumferential mucous folds. The mucous membrane lining of the major papillary orifice has exhibited two to four layers of folds, mucosal projections, and sometimes spiral arrangement; all are probably acting as valves controlling the biliopancreatic flow. The orifices on the major duodenal papillae are either single in 88% of specimens or double in the remaining 12%. Inner circular and outer oblique or longitudinal muscle fibers have been observed in the walls of the papillary stumps, probably offering a sphincteric action for the biliopancreatic flow. Other muscle fibers are noticed in the walls of the terminal ducts intermingling with the duodenal musculature. The present investigation has provided a detailed through description of the morphological and structural variations at the human choledocho-pancreatico-duodenal junction. An accurate knowledge of such variations might offer a helpful guide for clinicians during surgical and endoscopic procedures performed at this region

ileocaecal valve in man: anatomical, radiological and endoscopic studies with special reference to its antireflux mechanism

The uncertainty regarding the physio-anatomy of the ileocaecal junction, and in particular the question whether it acts as a valve or a sphincter, stimulated us to perform anatomical, histological, radiological and endoscopic studies of this junction. A clear understanding of the anatomical structure of the ileocaecal junction may throw some light on its function. Anatomical and histological studies were performed on 18 cadavers [mean age 34.2 +/- 18.4 years] and radiological on 22 [mean age 42.3 +/- 14.2 years] and endoscopic on 10 [mean age 38.6 +/- 7.9 years] healthy volunteers. Histological sections were stained with Masson's trichrome. The ileocaecal junction was studied radiologically using the method of small bowel barium meal follow through. Endoscopic study was done under controlled air inflation using a videoendoscope. A nipple [17-19 mm long] with transversely lying stoma protruded from the posteromedial wall of the caecum and a fornix was found on either of its sides. The nipple stoma was surrounded by two lips: upper and lower. Lateral and medial suspensory frenula started at the lateral and medial angles of the stoma respectively and extended along the whole caecal circumference in 44.4% or to half the circumference in 50%. They were marked on the external aspect of the caecum by a groove. The covering mucosa of the nipple showed mild rugae while the lining mucosa was smooth. Histologically, the musculosa of the terminal ileum extended into the ileocaecal nipple. The nipple contained mainly circular musclar fibers surrounded by adipose connective tissue. Radiologically, the ileocaecal nipple appeared as filling defect in the barium - filled caecum. As barium filled the terminal iteum, the ileocaecal nipple became distended with barium and appeared as a hen's beak; the nipple stoma then opened evacuating its contents into the caecum. The cycle of ileal filling, nipple distension and nipple evacuation was repeated every 6.6 +/- 1.4 seconds. The above mentioned observations were identified and confirmed endoscopically. From the findings observed in the present work it could be concluded that the ileocaecal nipple is closed at rest and it opens upon terminal ileal contraction to deliver ileal contents to the caecum. It evacuates the barium periodically into the caecum. The structure of the ileocaecal nipple seems to be adapted to serve the function of caeco - ileal antireflux

caecocolonic junction and sphincter in man: morphological, radiological and endoscopic study

Histomorphological and morphometric studies were carried out in 15 cadavers, radiological study was performed in 20 and endoscopic study in 16 healthy volunteers. Longitudinal histological sections along the caecum, the caecocolonic junction and the ascending colon were stained with hematoxylin and eosin as well as Masson's trichrome. The morphometric study determined the thickness of the muscle layers of the caecum, the caecocolonic junction and the asending colon using image analyser computer equipment. The caecocolonic junction was also examined radiologically by the method of small bowel barium meal follow through as well as endoscopically by pancolonoscopy. A caecocolonic fold was identified at 22-31 mm distal to the ileocaecal valve. It extended along the gut circumference and was shelf-like and marked by a shallow groove on the external aspect of the colon. Microscopically, the caecocolonic fold consisted of mucosa, submucosa, muscularis externa and serosa, all of which were a continuation of those of the caecal wall. The circular muscle layer of this fold was thicker than that of each of the caecum and the ascending colon. Branching cells with ovoid nuclei representing probably interstitial cells of Cajal were identified in the muscularis externa. The morphometric study also showed that the circular muscle layer was very highly significantly thicker than that of the caecum or the ascending colon [p < 0.001 and p < 0.001, respectively] while the longitudinal muscle layer exhibited no significant difference [p > 0.05 and p > 0.05, respectively]. Radiological study demonstrated narrowing at the caecocolonic junction which decreased on caecal contraction and increased or closed on ascending colonic contraction. Endoscopically, the caecocolonic junction was narrow due to the presence of the caecocolonic fold and sphincter which exhibited spontaneous contractions. In conclusion, the present study suggests the presence of an anatomical sphincter at the caecocolonic junction as evidenced histomorphometrically, radiologically and endoscopically. The muscularis externa was significantly thicker than that of each of the caecum and the ascending colon. Spasmodic contractions of the caecocolonic fold were observed on endoscopic examination. Radiological study showed dilatation and narrowing of the caecocolonic junction on caecal and ascending colon contraction, respectively. Absence of colocaecal reflux on colonic contraction is probably due to contraction of the caecocolonic sphincter. The detection of cells similar to the interstitial cells of Cajal, in the caecocolonic fold, postulates the possible existence of a pacemaker in the caecocolonic fold; a point that needs further investigation

Effects of exposure to phenobarbital on the embryogenesis in albino rat

Forty pregnant female albino rats of the Rattus Rattus Norvigicus strain were utilized in this work. They were divided into 10 rats in the control group, which were injected intramuscularly with distilled water [2 ml / kg / day] from the 6[th] to the 15[th] day of gestation, and 30 rats in the experimental group which were injected intramuscularly with 10 mg phenobarbital / kg / day during the period of organogenesis from the 6[th] to the 15[th] day of gestation. On the 20[th] day of gestation, the pregnant rats were sacrificed and the uterus and ovaries were removed. Gross morphological examination of all fetuses was performed then the fetuses were examined by free hand-razor blade sectioning, staining the skeleton with alizarin red stain and histological examination of serial sections of the fetuses using hematoxylin and eosin stains. The present study showed that administration of phenobarbital resulted in decreased number of pregnant rats which continued their pregnancy while the mean number of resorptions and dead fetuses was increased when compared to the control group. The fetuses exposed to phenobarbital in-utero showed under development and several congenital anomalies. The highest incidence of anomalies was recorded in the central nervous system in the form of hydrocephalus. Skeletal anomalies were observed in the form of delayed, incomplete or absent ossification in the lumber, sacral and tail vertebrae as well as bones of the hands and feet. Craniofacial anomalies were seen in the form of enlargement of the head, macroglossia, cleft palate, nasal septal defect and protrusion of eyeballs. Generalized oedema, cardiomegaly, bilateral polycystic lungs and club foot were also found. In conclusion, this study has revealed that phenobarbital administration during the period of organogenesis is teratogenic in albino rats. The possible teratogenic effect of phenobarbital in human being needs further investigations. The pregnant females should be prohibited from using this drug during pregnancy