Changes in the Peritoneum during the Development of the Testis, Epididymis and Ductus Deferens in the Pig

The development of the peritoneal folds of the testis, epididymis and ductus deferens of the pig prior to testicular descent was studied in 18 to 82 days-old embryos/fetuses. The parietal attachment of the mesonephros, mesonephric and paramesonephric ducts and gubernaculum constituted the urogenital mesentery. This could be divided in a cranial and a caudal part. The first fixed the mesonephros and had a mesogonad as a secondary fold. The second had two branches, one laterally to the umbilical artery belonging to the gubernaculum (Plica gubemacularis) and the medial to the artery contained the meso- and paramesonephric ducts. The mesogonad was related caudally with Plica gubemacularis. The fold of the meso- and paramesonephric ducts could also be divided in two parts. The caudal was a primary component of the urogenital mesentery, while the cranial was first ventral and later lateral to the mesogonad (mesorchium) and appeared as a secondary fold of the urogenital mesentery (cranial part). A vascular fold contributed to separate the suspensory ligament of the testis from the developing mesorchium. The proposed meaning of the terms used might be useful for comparative studies.     

The Development of the Genital Peritoneum in Domestic Mammals. An Analysis of the Literature and Nomenclature

This review presents and discusses the reasons for the currently employed anatomical terminology relating to the genital peritoneum of various domestic species, based upon its prenatal development. When reviewing the development of genital organs, attention must be paid to changes in the related peritoneum in order to define currently used terminology more clearly. The relevance of some terms such as Caudal genital ligament, Plica gubernaculi, Plica iguinalis and genital fold is considered. A System of serosal folds, the Plica gonadoinguinalis or genitoinguinalis, seems to be a useful term to be added to the Nomina Embryologica Veterinaria.     

Laparoscopic cryptorchidectomy using electrosurgical instrumentation in standing horses

OBJECTIVE: To describe a technique for laparoscopic cryptorchidectomy in standing horses using electrosurgical instrumentation. STUDY DESIGN: Retrospective clinical study. ANIMALS OR SAMPLE POPULATION: Ten horses, 1 to 7 years of age, with unilaterally or bilaterally retained testes. METHODS: Food was withheld for a minimum of 12 to 24 hours. Horses were sedated using xylazine hydrochloride (0.5 to 1 mg/kg) and butorphanol tartrate (0.02 mg/kg) or detomidine hydrochloride (0.02 to 0.03 mg/kg) and restrained in standing stocks. Three portal sites in the paralumbar fossae were locally desensitized using 2% mepivacaine. After trocar and laparoscope insertion, the ipsilateral testicle, mesorchium, and ductus deferens were identified. The cranial mesorchium was coagulated with either monopolar (one horse) or bipolar (nine horses) electrosurgical forceps, and then the mesorchium, ductus deferens, and ligament of the tail of the epididymis were transected from cranial to caudal using laparoscopic scissors. Once the testis was freed, the transected mesorchium was inspected for hemorrhage and the testis was removed by connecting the two instrument portals (eight horses). In two horses, the testis was placed within a laparoscopic retrieval bag and then removed without enlarging the portal incision. If the testes were retained bilaterally, the retained contralateral testis was removed similarly through the opposite paralumbar fossa. If the contralateral testis was descended, it was removed by a standard, standing castration technique. RESULTS: Vessels of the mesorchium were adequately coagulated using bipolar and monopolar electrosurgical forceps. No immediate or short-term complications occurred in 10 horses at 3 to 11 months after surgery. CONCLUSION: Standing laparoscopic cryptorchidectomy can be performed easily and safely using electrosurgical instrumentation as the sole means of providing hemostasis of the equine mesorchium. CLINICAL RELEVANCE: Standing laparoscopic cryptorchidectomy using electrosurgical instrumentation provides a safe, reliable, and efficient alternative to achieve hemostasis of the equine mesorchium.     

Macroscopic and microscopic anatomy of the oviduct in the sexually mature rhea (Rhea americana)

The morphological characteristics of the oviduct of 12 sexually mature rheas (Rhea americana) were studied. Only the left oviduct is developed as a long tube with a length of 122 +/- 23.1 cm, and is subdivided into infundibulum (15.2 +/- 4.0 cm), magnum (63.3 +/- 9.4 cm), isthmus (5.6 +/- 3.1 cm), uterus (16.0 +/- 4.2 cm) and vagina (11.5 +/- 1.4 cm). The mucous membrane of the oviduct, as a whole, possesses luminal folds covered by ciliated columnar epithelium with secretory cells. The infundibulum part presents a cranial opening with thin and long fimbriae with few tubular glands in caudal tubular portion. In the magnum, the largest portion of the oviduct, the folds are thicker and are filled with tubular glands. The isthmus is short and presents less bulky folds and a few tubular glands. A bag-shaped uterus in the cranial area shows thin folds, and in the caudal region (shell gland) more ramified folds with few tubular glands. The vagina has long luminal folds and a thick muscular tunic; no glands with sperm-storage characteristics have been observed. In conclusion, the oviduct in sexually mature rhea has morphological similarities with the other species of birds already described; however it presents its own characteristics to produce a big egg.     

Laparoscopic ovariectomy using sequential electrocoagulation and sharp transection of the equine mesovarium

OBJECTIVE: To describe in horses and ponies a laparoscopic ovariectomy technique facilitated by electrosurgical instrumentation. STUDY DESIGN: Elective ovariectomy was performed in 23 mares using laparoscopic electrosurgical instrumentation. ANIMALS OR SAMPLE POPULATION: Twenty-three mares (13 horses, 10 ponies), aged from 2 to 21 years and weighing 90 to 545 kg. METHODS: Food was withheld for a minimum of 12 hours. Mares were sedated with detomidine hydrochloride (0.02 to 0.03 mg/kg) or xylazine hydrochloride (0.5 to 1.0 mg/kg). Excluding the pony mares, all other mares were restrained in stocks. Portal sites in the paralumbar fossa region were desensitized with 2% mepivacaine. Abdominal insufflation was achieved through a teat cannula positioned in the ventral abdomen or a Verres-type needle placed through the paralumbar fossa. After trocar and laparoscope insertion, the ipsilateral ovary and mesovarium were identified, and the mesovarium, tubal membrane, and proper ligament were infiltrated with 2% mepivacaine. The mesovarium was coagulated using bipolar or monopolar electrosurgical forceps and transected sequentially from cranial to caudal until the ovary was completely freed and then removed. The contralateral ovary was removed in a similar fashion through the opposite paralumbar fossa. RESULTS: Bipolar and monopolar electrosurgical forceps were easy to use and provided adequate coagulation of vessels within the mesovarium. Two mares were euthanatized after the procedure for unrelated reasons. One mare had mild signs of colic 24 hours after ovariectomy. In 1 pony mare, the incision used to remove one ovary dehisced on the 5th postoperative day and was allowed to heal by second-intention. No long-term complications had occurred in 11 horses and 10 ponies, 6 to 24 months after surgery. CONCLUSION: Laparoscopic ovariectomy and hemostasis of the mesovarium can be easily accomplished using electrosurgical instrumentation. CLINICAL RELEVANCE: Standing laparoscopic ovariectomy, using electrosurgical instrumentation, is an effective and safe technique to provide hemostasis of the mesovarium in mares.     

Observations on the macroscopic anatomy of the intestinal tract and its mesenteric folds in the pampas deer (Ozotoceros bezoarticus, Linnaeus 1758)

We described the macroscopic anatomy of the intestines and their peritoneal folds of five adult pampas deer ( Ozotoceros bezoarticus ), a cervid species considered to ingest a high proportion of grass in its natural diet. The mean (±SD) body weight was 17 (±2) kg. The small intestine and the caecocolon measured 495 (±37) cm and 237 (±24) cm in length, respectively, with an average ratio (small intestine:caecocolon) of 1.9 (±0.1). The ascending colon had two and a half centripetal gyri, a central flexure and two centrifugal gyri. The spiral ansa, which was similar to an ellipse, was fixed to the whole left face of the mesenterium. Apart from the peritoneal folds described in the Nomina Anatomica Veterinaria, three additional, hitherto not described folds were found: a fold that fixed the caecum to the proximal ansa of the ascending colon, one that joined the terminal part of the proximal ansa to the last centrifugal gyrus of the spiral ansa of the ascending colon, and one that linked the ascending duodenum to the proximal ansa of the ascending colon. When compared with published data from other cervids of different feeding niches, it appears that, among cervids, the ratio of small intestine to the caecocolon length does not reflect the natural diet.     

Histomorphometric Analysis of Collagen and Elastic Fibres in the Cranial and Caudal Fold of the Porcine Glottis

The porcine glottis differs from the human glottis in its cranial and caudal vocal folds (CraF, CauF). The fibre apparatus of these folds was studied histomorphometrically in adult minipigs. For object definition and quantification, the colour‐selection tools of the Adobe‐Photoshop program were used. Another key feature was the subdivision of the cross‐sections of the folds into proportional subunits. This allowed a statistical analysis irrespective of differences in thickness of the folds. Both folds had a distinct, dense subepithelial layer equivalent to the basement membrane zone in humans. The subsequent, loose layer was interpreted – in principle – as being equivalent to Reinke's space of the human vocal fold. The next two layers were not clearly separated. Due to this, the concept of a true vocal ligament did not appear applicable to neither CauF nor CraF. Instead, the body‐cover model was emphasized by our findings. The missing vocalis muscle in the CraF is substituted by large collagen fibre bundles in a proportional depth corresponding to the position of the muscle of the CauF. The distribution of elastic fibres made the CraF rather than the CauF more similar to the human vocal fold. We suggest that these data are useful for those wishing to use the porcine glottis as a model for studying oscillatory properties during phonation.     

Relationship between the development of the gubernaculum and the testicular descent in the rat fetus: macroscopic and light and electron microscopic observation

The gubernaculum consists of the gubernacular cord connected with the vas deferens and the gubernacular bulb connected with the retroabdominal wall. The cord was first distinguished on day 15 of gestation. Its length reached the peak on day 16, followed by a reduction until day 18 to be almost constant thereafter. The bulb was first distinguished on day 16, and its length was steadily increased toward term. The testis began to descend with a reduced length of the cord. By day 19, the testis descended close to the caudal part of the bulb by the sharp bending of the cord. Microscopically, the bulb consisted at first of a centrally located mesenchymal mass and of a covering layer of myoblasts. Thereafter, the mesenchymal mass was gradually shifted toward the cranial part of the bulb, trailing loose mesenchymal tissue in the caudal part of the bulb. On day 19, the mass was decreased in cell population but increased in amount of collagen fibers. It is suggested that the testicular descent starts on day 16 together with the commencement of shortening of the gubernacular cord and enlargement of the gubernacular bulb.     

Origin of the infrarenal part of the caudal vena cava in the pig

The vascular topography in the lumbar region of pig embryos and young fetuses was three-dimensionally reconstructed to study some controversial aspects of the origin and development of the infrarenal part of the caudal vena cava. Contrary to general belief, it was found that the supracardinal veins, which form the azygos veins in the thorax, do not take part in the construction of the caudal vena cava in the lumbar region. These veins do appear in the abdomen, but they are only involved in the formation of the lumbar and ascending lumbar veins. The infrarenal part of the caudal vena cava arises from the lumbar part of the right caudal cardinal vein. Whilst this venous pattern is established, the lumbar part of the left caudal cardinal vein disappears and its former location is occupied by large lymphatic connections between the cysterna chyli and the retroperitoneal mesenteric lymphatic sac. On the basis of these findings, a number of hypotheses on the development of anatomical variations of the caudal vena cava should be reconsidered.     

Scanning electron microscopic and histological features of the oral cavity of the Egyptian tortoise (Testudo kleinmanni)

This investigation was led to depict the structural and functional adaptations of the oral cavity of herbivorous Egyptian tortoises using scanning electron and light microscopes. The SEM showed that the triangular papillary tongue possessed three conical papillary subtypes: the rectangular conical on the tip, the round conical on the rest of the dorsal lingual surface and the elongated conical on the caudal portion of the lingual wing. The presence of the serrated lips with their valves compensated for the absence of the teeth. The rostral part had a vomeronasal opening while the middle part had the choana, but the caudal part had numerous openings of the salivary glands. There are three palatine folds: a single median palatine fold, two peripheral palatine folds and the choanal fold. The current histological results show the keratinized dorsal lingual surface, in which the keratinized layer extended to cover the papillae. Two types of lingual glands, according to their position, are papillary superficial and deep lingual glands. Papillary or superficial glands open in the interpapillary spaces via narrow openings, while the deep glands are surrounded by well-developed muscles and open via wide openings on the dorsal lingual surface. An entoglossal cartilaginous structure of hyaline cartilage was found in the mid- and hindtongue, with numerous chondrocytes lodged within the lacunae. Our results conclude that the oral cavity of the herbivorous Egyptian tortoise was adapted to the dietary and vigorous demands of the Egyptian fauna.     

Macroscopic features of the arterial supply to the reproductive system of the male ostrich (Struthio camelus)

The macroscopic features of the arterial supply to the reproductive system of the male ostrich was studied in 16 pre-pubertal and eight sexually mature and active birds. The left and right cranial renal arteries arise from the aorta, between the cranial divisions of the kidneys. These vessels supply the cranial divisions of the kidneys, the testes, the epididymides and the cranial segments of the ducti deferentia. Accessory testicular arteries which arise directly from the aorta are present in 45.8% of the specimens. They supply the testes and cranial parts of the ducti deferentia. They are variable in number and origin, and four variants are identified. A cranial ureterodeferential branch originates from the cranial renal artery, supplies the cranial portion of the ductus deferens and ureter, and runs caudally to anastomose with the middle renal artery. The sciatic artery arises laterally from the aorta, just caudal to the acetabulum, and gives rise, ventrally, to a common trunk, the common renal artery, which divides into the middle and caudal renal arteries. The middle renal artery gives rise to the middle ureterodeferential branch which supplies the middle part of the ductus deferens and ureter. A few centimetres caudal to the kidney, the aorta terminates in three branches, namely, the left and right internal iliac arteries and the median caudal artery. The internal iliac artery divides into the lateral caudal artery and the pudendal artery; the latter gives off caudal ureterodeferential branches that supply the caudal segments of the ductus deferens and ureter. In addition, the pudendal artery gives off vessels that supply the cloaca, some of which continue to the base of the phallus, where they form an arterial network. In conclusion, the pattern of the blood supply to the reproductive organs of the male ostrich is, in general, similar to that of the domestic fowl and pigeon, although there are a few highlighted distinctive features.     

Pyometra in an Inguinal Hernia in a Bitch

Pyometra in an inguinal hernia was diagnosed in a 10‐year‐old intact cross‐bred bitch which had had dysorexia, depression and inguinal distension. The hernia contained caudal portions of the two uterine horns, uterine cervix and cranial part of the vagina. As the organs were enlarged and full of pus, manual attempt to push back the uterine horns and the vagina in the abdominal cavity through the inguinal canal was unsuccessful. Herniated uterine horns were ligated and cut in their median portion, so it became possible to remove the cervix and the caudal portion of the horns through the hernial orifice, and the ovaries and the cranial part of the horns through a peritoneal midline incision. This bitch was not intended for breeding purposes and, given the presence of a huge pyometra associated with an inguinal hernia, an ovario‐hysterectomy was recommended. Uterine herniation should be considered as a differential diagnosis of a caudal lateral inguinal mass. When pushing the uterus back in the abdominal cavity is impossible, a surgical procedure should be performed to detect ischemia–reperfusion injury and/or a septic risk.     

Origenes de las arterias suprarrenales craneales y caudales de la rata albina (Rattusnorvegicus)

The origin of the cranial and caudal adrenal arteries were studied in the white laboratory rat. Colored latex neoprene was utilized in this investigation. The adrenal arteries were found to arise from the caudal phrenic or adrenophrenic trunks. Variations in origin are discussed.     

The Arterial Supply of the Male Reproductive System in the Hamster

The major arteries, the testicular, deferential, prostatic, internal pudendal and external pudendal arteries, supply the male genital organs of the hamster. The same arterial patterns are found in three strains, except that the external pudendal artery arises from the external iliac artery or internal iliac artery in the APG strain, but only from the external iliac artery in the CBN and ACN strains. The deferential and prostatic arteries form the arterial loop on the dorsal surface of the ventrolateral lobe of the prostate. This loop may play some importance parts in the functional interaction between the epididymis and the prostate. The caudal epididymal artery arises more frequently from the spermatic cordai portion of the testicular artery than from the cranial epididymal artery, and it never arises directly from the abdominal part of the testicular artery as reported in the rat, mouse and rabbit. The deferential artery may join with the cranial vesicular artery to form the common trunk (umbilical artery), but sometimes these arteries arise directly from the internal iliac artery.     

Intraperitoneal Circulation and Drainage in the Dog

The patterns of dispersion and drainage of a low viscosity, oil-based contrast medium within the peritoneal cavity were examined in 12 normal dogs. Intraperitoneal injection of contrast medium was cranial or caudal and drainage was by the sump-Penrose or open peritoneal method. Radiographs were made over a 96 hour period, before and after peritoneal drainage was established. Each dog was euthanatized and necropsied. The contrast medium was dispersed throughout the peritoneal cavity 15 to 30 minutes after cranial injection and 1 to 2 hours after caudal injection. Most of the contrast medium drained within 6 hours after open peritoneal drainage and within 24 to 48 hours after sump-Penrose drainage. At necropsy, there was complete encasement of all sump-Penrose drains and partial occlusion of all open peritoneal incisions by omentum adhered to the abdominal wound edges. Peritonitis was not grossly evident, but all dogs showed histologic evidence of an acute inflammatory reaction associated with the drain or wound edge.     

Comparison of collagen fibre architecture between slow-twitch cranial and fast-twitch caudal parts of broiler M. latissimus dorsi

1. Collagen fibre architectures of perimysium and endomysium in the slow-twitch cranial and fast-twitch caudal parts of broiler M. latissimus dorsi were compared. 2. Type I and III collagens were distributed in both perimysium and endomysium as indicated by their positive immunohistochemical reactions to polyclonal antibodies. 3. Cells invested by endomysium with no myofibres were larger in the cranial part because of the presence of larger slow-twitch myofibres. The honeycomb structure of endomysium was divided into several parts by thick perimysium. 4. The thick perimysial collagen fibres with parallel fibrils, which were interconnected by the loose reticular fibrils and thin fibres, were more numerous and thicker in the cranial part than the caudal. 5. Thick endomysial sidewall of cells in the cranial part was composed of a rougher reticulum of slightly thicker collagen fibrils compared with the thin sidewall in the caudal part. 6. These results indicated that both perimysial constitutions of collagen fibres and endomysial collagen fibrils had attained much larger growth in the slow-twitch cranial part than the fast-twitch caudal in broiler latissimus dorsi muscle.     

XX true hermaphroditism in a dog

XX True hermaphroditism was identified in a 5-month-old German Shorthaired Pointer with a large clitoris. The gonads were situated caudal to the kidneys at the cranial tips of the uterine horns, and were composed mainly of seminiferous tubules and interstitial cells and had ovarian follicles in the cortices. Each gonad had efferent tubules, a pampiniform plexus, fimbriae, and a uterine tube. The uterus was positioned normally in the abdomen and had no gross or histologic abnormalities. Giemsa-banded karyotypes revealed a normal female 78,XX chromosomal complement with no structural abnormalities.     

Morphological study on the stomach of the lesser mouse deer (Tragulus javanicus) with special reference to the internal surface.

The stomach of the lesser mouse deer (Tragulus javanicus) was observed macroscopically. It consisted of only three compartments, rumen, reticulum and abomasum without omasum. The rumen was S-shaped with large ventral and caudoventral blind sacs and the reticulum was larger than the abomasum. Internally, the rumen was covered with numerous ruminal papillae even on the pillars and the ruminoreticular fold. These papillae were leaf- or tongue-like shaped and varied in size and density. The reticulum had honey-combed crests and the secondary crests were found rarely. The lips of the reticular groove were prominent and more developed in the aboral part than in the oral one. A sac-like transition zone, which had more prominent mucosal folds than had the floor of the reticular groove, was observed between the caudal end of the reticular groove and the abomasum. Mucosal folds of the abomasum were spiral, low but rather thick. These findings were discussed in view of comparison with other ruminants and of possible functional implications.