Anatomy & distribution of coronary arteries in pig in comparison with man.

BACKGROUND & OBJECTIVE: The suitability of pig as an animal model for research in coronary artery disease is well established. As coronary arteries (CAs) of the pig are reportedly closely resemble those of man. We investigated the CAs of the pig (Sus scrofa) and study differences between the two, if any. METHODS: The origin and pattern of the coronary arteries were studied in the hearts of 30 fully grown pigs obtained from a slaughter house in Chandigarh (India). The openings of the CAs were identified at the commencement of the ascending aorta. The arteries were washed with acetone by introducing appropriate sized cannulae in their ostia. A 20 per cent solution of cellulose acetate butyrate (CAB), a plastic material, dissolved in acetone was injected in the CAs. The hearts were fixed in 10 per cent formalin solution for three to four days after which the CAs and their branches were dissected. RESULTS: Both coronary arteries arose from the aortic sinuses below the supravalvular ridge in all the cases. Sinuatrial nodal artery (SAN) arose from the RCA in 70 per cent and from the circumflex artery (CX) in 30 per cent of instances. There was RCA dominance in all hearts of the pig. The atrioventricular nodal artery (AVN) and the posterior interventricular artery (PIV) were branches of RCA. The coronary arterial circulation in the pig was found to be similar to that in human. INTERPRETATION & CONCLUSION: By and large the coronary arterial pattern of the pig was similar in that of the humans. We can conclude that the heart of a pig can be used for experiments but differences have to be kept in mind.

Filiform papillae in the mucosa of the human vaginal wall.

BACKGROUND & OBJECTIVE: While giving the gross anatomy of the mucosa of the vagina, textbooks of Anatomy and Obstetrics and Gynaecology describe the presence of a median longitudinal ridge on its anterior wall (columna rugarum anterior) and another similar ridge (columna rugarum posterior) on its posterior wall is described, and transverse rugae separated by sulci of variable depth, extend bilaterally from these ridges. While conducting autopsy of female cases the routine examination of vaginal mucosa did not show the presence of longitudinal ridges. In addition, some small areas bearing filiform papillae were seen in the lower third of the vagina in young subjects. As these papillae have not been described earlier, it was decided to study them in detail using scanning electron microscopy. METHODS: A total of 215 vaginal specimens were studied. At autopsy the vagina was slit open on the lateral sides up to the upper ends of the lateral fornices. The anterior vaginal wall was turned up over the uterus and mucosa of both walls examined macroscopically. In 16 subjects, small pieces of vaginal mucosa bearing filiform papillae were cut out and processed for examination under scanning electron microscope (SEM) and a light microscope. In addition, vaginae of 55 married women (20-40 yr age) with complain of lower abdominal pain or infertility were examined particularly for the median longitudinal ridges on the vaginal walls. RESULTS: At autopsy, the two median longitudinal ridges were not seen in any instance. Small variable areas of the lower third of the vagina showed the presence of filiform papillae on the two walls and at sides; they were prominent in the young individuals and tended to become absent in multipara and in old age. They were 2 to 3 in number on each wall. Histologically the papilla showed a core of highly vascular connective tissue covered by non-keratinized squamous epithelium. Immunoperoxidase staining with S-100 showed a large number of small nerve fibres in the subepithelial tissue which seemed to be more than in the surrounding areas not covered with papillae. INTERPRETATION & CONCLUSION: Anterior and posterior median longitudinal ridges were not seen on the vaginal mucosa in the autopsy specimens. In all autopsy specimens of young subjects between the ages of 15 and 40 yr, variable areas bearing filiform papillae were observed on the mucosa of the lower third of the vagina. Further studies need to be done to throw light on the role of these papillae.

Dimensions & weight of the cricoid cartilage in northwest Indians.

BACKGROUND & OBJECTIVES: Information on the diameters of the cricoid cartilage in northwest Indian children and adults is scanty. As injury to the mucous membrane of the larynx could occur when an endotracheal tube or a laryngoscope, selected on the basis of western data, is introduced into the larynx of patients. It was, therefore, considered necessary to study the diameters of the cartilage. METHODS: Cricoid cartilages were obtained from 100 male and 58 female adults, 25 male and 25 female children and adolescents on whom medico-legal postmortems were done. In addition, cartilages of 25 dead newborns were studied. Measurements taken included height and thickness of the lamina and anterior arch, anteroposterior and transverse diameters, circumference, length and breadth of the cricoarytenoid facets and angle between their long axes. RESULTS: With advancing age, there was an increase in the weight and in most of the measurements of the cartilage in the newborns, children and adolescents, and adults. Sexual dimorphism in weight and measurements became evident only after the age of 17 yr. INTERPRETATION & CONCLUSION: The weight and other measurements of the cricoid cartilage in northwest Indians are smaller than those recorded in the western populations. The tubes of appropriate size should therefore be used for intubation in different age groups particularly in children based on measurements taken in Indians. Use of the western measurements/standards for this purpose is not recommended. In case of a highly decomposed body, the measurements and weight of the cartilage may be useful in gender determination.

Hepatic veins in northwest Indian subjects.

Formation, position, course and areas of drainage by hepatic veins were studied in 153 adult autopsy specimens. There were three major hepatic veins; left, middle and right. The middle hepatic vein (MHV) joined the left hepatic vein (LHV) in 88.2% specimens before the latter opened into inferior vena cava (IVC). Each major hepatic vein was joined by a superior vein. An intersegmental vein was present in the septum between the medial and lateral segments; it either joined the LHV or MHV. Formation and course of posterior hepatic veins (small veins) have been described and a nomenclature has been suggested. The right suprarenal vein either opened directly into IVC or joined the superior or inferior posterior hepatic veins.