[Comparative ontogenic analysis of the epithelium of the non-glandular stomach compartments of merino sheep]. / Estudio ontogenico comparativo de la lamina epitelial de los compartimentos gastricos no glandulares en ovinos merinos.

A total of 74 embryos and fetuses were used in a comparative analysis of the epithelium of the non-glandular stomach compartments of merino sheep during development. The mechanical protection showed by the tegumentary epithelium in the superficial layers of the rumen, reticulum and omasum is supported by a buffer system of neutral mucopolysaccharides secreted by the deeper strata. Neutral mucopolysaccharides first appeared in epithelial cells at 46 days of fetal life. Acid mucopolysaccharides, mucins, and mucoid compounds were not detected. Growth curves and formulas were constructed for the epithelial layers.

[Mathematical models applied to the growth of the ovine stomach during intrauterine life]. / Modelos matemáticos aplicados al crecimiento gástrico ovino durante la vida intrauterina.

One hundred forty four ovine embryos and feti were used in an investigation to determine mathematical models describing the histomorphometric growth of tissues and compartments of the ruminant stomach. The results indicate that during prenatal life the diameter of the gastric chambers increase more slowly than the length. The tissue layers of the gastric walls, particularly the muscular tunic of all compartments demonstrated a uniform tendency toward more rapid development than the compartment walls proper.

Histogenetic evolution of bovine gastric compartments during the prenatal period.

In order to carry out this study, 62 embryos and fetuses of Friesian cows were used, and every stomach was dissected and subjected to the usual laboratory procedures. After obtaining each preparation all the histological and metrical changes that took place in the wall of the viscus during its development are described. The compartments are histologically differentiated into three stages: in the first one there is no compartment differentiation: in the second one, the rumino-reticulum, omasum and abomasum have differentiated; and in the third one every compartment is differentiated. In group 16, (78 days of gestation), a decrease in thickness of the muscular layer of all compartments, parallel to the histological differentiation has been observed.

Early organogenesis of the caprine stomach.

Early organogenesis of the caprine stomach was studied in a series of 11 embryos ranging from 6.5 mm neck-rump length (NRL) to 13.3 mm crown-rump length (CRL). In embryos with 6.5-6.7 mm NRL, a part of the primordial proper esophagus extended to the dorsal side of the primordial stomach. The primordial proper esophagus and its extension were lined with a simple epithelium and stained dark brown with Con A III, while the primordial stomach was weakly stained. In embryo with 7.3 mm NRL, the esophageal extension was separated from the proper esophagus by constriction, and became a primordial forestomach situated in an area outside the omental sac. In embryos with 8.3 mm NRL-10.7 mm CRL, primordial forestomach and primordial stomach were united and formed a spindle shaped primordial ruminant stomach with foregut rotation. The primordial ruminant stomach was similar to the primordial simple stomach except that it was more flattened laterally with the convex at the area of 'lesser curvature'. Primordial rumen, omasum and abomasum appeared from the spindle shaped primordial ruminant stomach in an embryo with 12.9 mm CRL. In an embryo with 13.3 mm CRL, primordial reticulum originated from an area between the primordial rumen and omasum.

Histogenesis of the reticular groove of the buffalo (Bubalus bubalis) stomach.

Histogenesis of the reticular groove (sulcus reticuli) of the buffalo (Bubalus bubalis) was observed from primordial stage to birth. The epithelium of the reticular groove was considered early embryonic until a crown-rump (CR) length of 2.2 cm, and was uniformly distributed at CR 2.2 cm; superficial and basal zones developed by CR 3.2. cm. At CR 10.5 cm, the basal zone in the floor evaginated and formed longitudinal folds. At CR 25.5 cm, the basal zone in the lipids evaginated and formed papillae. The core of the longitudinal folds and papillae was formed by the lamina propria, muscularis mucosae, and submucosa. Keratinization was seen at CR 50.5 cm, and the epithelium was stratified squamous epithelium with keratinization, similar to that of the adult buffalo. The floor and lip had a single layer of muscle. A small oblique muscle layer was also found in the concavity of the lip. The correlation between structure and function of the reticular groove is discussed.

[Distribution of the vagus nerve of the stomach and certain lymph nodes of the sheep in the prenatal period (author's transl)]. / Die Versorgung des Magens und einiger Lymphknoten durch den Nervus vagus beim Schaf in der pränatalen Periode.

The goal of this study was the investigation into the vagus nerve structure in the ruminant stomach, and a description of the participation of this nerve in the stimulation of the atrial lymph nodes of the rumen and dorsal abomasal lymph nodes. This survey was carried out on 30 sheep fetuses, whose ages are designated according to Zietzschmann and Krölling (1955). The fetuses came from the third to fifth months of pregnancy. Observations and general morphological nature may be summarized as follows: 1. to the wall of the rumen reach atrial branches coming from both vagus trunks plus a dorsal ruminal branch, and a right ruminal branch coming from the dorsal vagus trunk, 2. the reticulum receives reticular branches, coming from both vagal trunks, 3. the omasum is innervated by omasal branches of the dorsal vagus trunk plus an omasoabomasal branch coming from the ventral vagus trunk, 4. to the wall of the abomasum reach the reticulo-abomasal and pyloric branches coming from the ventral vagus trunk plus a branch to the major abomasal curvature and a visceral abomasal branch coming from the dorsal vagus trunk, 5. arterial lymph nodes of the rumen receive innervation from the reticulo-abomasal branch or the pyloric branch, both leaving from the ventral vagus trunk, 6. dorsal abdominal lymph nodes innervated by nerve branches coming from a parietal abomasal branch, coming also from the ventral vagus trunk.

Histological and histochemical observations on the forestomach of goat during pre-natal life.

Non-keratinized, stratified squamous epithelium lined the mucosa of the fore-stomach. The mucosal appendages in the form of ruminal papillae did not develop in the rumen during this study, however, omasal laminae and reticular ribs were evident in groups I and II, respectively. Cytoplasmic accumulations were evident in the middle layer of the epithelium, which is characteristic of this region. The thickness of the epithelium increased constantly in the rumen and reticulum, but in the omasum it remained constant with the increase in the size of the fetus. The corial papillae in the rumen, reticulum and omasum appeared at the 12.7-, 11.5-and 14.6-cm CVR stage, respectively. The muscularis mucosae appeared in the omasum at the 14.6-cm CVR stage in the first-order laminae. The tunica muscularis consisted of spirally arranged muscle fibre bundles. Cross-cut muscle fibre bundles below the tip of the omasal laminae descended downward with the increase in the size of the fetus and continued with the inner circular layer. Acid and alkaline phosphatases and fat could not be observed. The concentration of glycogen in the epithelium was maximum in group III and minimum in group II.