Background & Aim: The present study is aimed to document the histological changes of thymus gland during different weeks of gestation in human fetuses. Materials & methods: Fifty-three human fetuses (30 males and 23 females) of different age groups ranging from 9th to 40th gestational week were procured from the Department of Obstetrics and Gynaecology, Sree Balaji Medical College and Hospital, Chennai and from Mahathma Gandhi Medical College, Puducherry. The fetuses were dissected. The thymic tissues thus obtained were immersed in 10% formalin for one week. After proper fixation, the tissue was subjected to routine processing and then the sections were stained with Haematoxylin and Eosin for microscopic examination. Results : Formation of lobules had started at 9th week and distinct formation of lobules was observed during the 12th week. The differentiation of the cortex and the medulla became well distinguished from the 14th week onwards. Presence of Hassall’s Corpuscles was observed from 14th week and was found in all sections from 15th week onwards. Hassall’s Corpuscles increased in number, size and maturity with the increase in the gestational age. Conclusion: Familiarity with the embryology, anatomy, and dynamic physiology of the thymus is essential for clinicians to avoid unnecessary imaging or invasive procedures.

Background: The infra orbital foramen (IOF) situated below infra-orbital margin (IOM) transmits infraorbital nerve and infra- orbital vessels. The knowledge of the dimension, shape and direction of the IOF has important implications in various surgical and anaesthetic procedures. This will avoid iatrogenic injury to neurovascular bundle emerging from the IOF. Material and methods: Sixty adult dry skulls of unknown sex from the Department of Anatomy and Department of Forensic Medicine were used. IOF on both sides of skulls were assessed for the shape and direction by inspection. The vertical and horizontal diameter of the IOF was measured using a digital Vernier caliper to the nearest millimeters and the results were statistically analyzed. Results: The shape of the IOF was vertically oval in majority of the skulls (37.5%) and was semi lunar shaped in 10.83% of the skull. The IOF was directed infero- medially in about 52.5% of the cases and was directed medially in 6.67% of the cases. The mean transverse diameter was 2.96mm and the mean vertical diameter was 3.7mm. All the above results were compared with studies of previous workers. Conclusion: The present study confirms that there is racial as well as regional variation in the shape and dimensions of IOF, thus emphasizing the need to have morphometric data for South Indian population.

Background: Caudal anaesthesia is administered into the epidural space through Sacral Hiatus(SH). Hence reliability and success of caudal epidural anaestheia depends upon the anatomical knowledge of sacral hiatus. Aim: The aim is to study the morphological measurements and variations of structures around the sacral hiatus and to identify possible anatomical reasons for failure of caudal epidural anaesthesia (CEA). Materials and methods: Fifty three dry adult sacral bones of both sexes were measured using Vernier Caliper, scale and divider. The shape of sacral hiatus (SH) was observed and its length and breadth were measured. The measurements were focused on sacral hiatus and its relation with surrounding bony projections. Results: The shape of the sacral hiatus showed a maximum occurrence of inverted ‘V’ and ‘U’ shapes with 35.85% and 26.42% respectively. The level of apex of SH was maximum at 54 foramen level in 68.63% cases followed by S5 and S3 level. In 62.26%, the level of base was observed at 55 level .The average length of the sacral hiatus was 23.02(± 8.95mm), AP diameter was 5.49 (± 1.44mm) and base of SH was 14.6 (± 3.99mm). The distance from apex and base of SH to S2 foramen level was 31.07mm and 52.86mm respectively. Conclusion: The anatomical knowledge of SH is very much necessary to increase the reliability and success of CEA. Surrounding bony irregularity, different shapes of hiatus and defect in dorsal wall of sacral canal should be taken into consideration before undertaking CEA so as to avoid its failure.

Background and Objectives: The role of genomic instability resulting from chromosomal aberrations, gene mutations due to deletions, translocations and single gene defects is a known phenomenon leading to DNA damage. A deficient repair process is also attributed to the perpetuation of this damage. Placental insufficiency in pregnancy during late embryonic or early fetal period resulting in DNA damage gives rise to malformed phenotypes. An attempt was made to study the extent of DNA damage in non syndromic congenital malformations. Materials and Methods: A total of 20 children were studied. 10 of them, between 10 days to 5 years of age, presenting with non syndromic congenital anomalies formed the cases. An equal number of children matched for age criteria formed the controls. Lymphocytes collected from peripheral blood of these children were subjected to the standard comet assay, an highly sensitive, reliable, relatively inexpensive and reproducible single cell layer electrophoretic technique, where damaged DNA migrates out of the cell towards the anode forming a comet. The length of the tail is a measure of the DNA damage. Results: The malformations observed were those of urogenital, craniofacial and nervous systems. The mean comet tail lengths were 24.744 20.649 |im and 27.402 |im respectively. Comparing this to the mean tail length in controls with 1.992 fim, there was high statistical significance (P value <0.0001). Conclusion: Gene mutations, particularly involving Sex Region Determining (SRD) genes and Superoxide Dismutase (SOD) enzyme imbalances, have been implicated in these congenital malformations. Thus the comets seen in this study reflect the DNA damage due to the gene defects.

Background and aims: The incidence of Coronary Artery Disease (CAD) has reached alarming proportions in India. The pathological hall mark of CAD is myocardial ischemia resulting from the atherosclerotic narrowing of coronary arteries. In this era of advanced interventions and cardiac surgery, a thorough knowledge of normal and variant anatomy of coronary arteries is of prime significance and of great use both to the clinicians and anatomists. Materials and methods: One hundred coronary angiograms of patients free of disease were studied in detail in different profiles. The data obtained was quantified according to their frequencies. The relation between the length of left main coronary artery and coronary artery dominance was statistically analyzed using the ‘Chi Square test for Trend’. Results: This study highlighted some interesting findings such as the origin of Sino- atrial nodal artery from the second segment of right coronary artery in 3% of cases, double right marginal artery in 4% cases. Other variations such as Mouchet’s posterior recurrent interventricular artery, origin of circumflex artery from the right coronary artery and abnormal communication between the terminal parts of right coronary artery and circumflex artery were each noticed in 1 % of cases. Conclusions: Coronary arteries and their branches are prone to variations in their course and morphology. Prior knowledge about this is important for the interpretation of coronary angiograms and surgical myocardial revascularization. The present work on normal and variant pattern of coronary arteries will help in gathering momentum to the already advancing research work in this field.

Developmental anomalies of the Mullerian duct system represent some of the most fascinating disorders that obstetricians and gynaecologists encounter. The uterus is formed during embryogenesis by the fusion of the two paramesonephric ducts (Mullerian ducts). This process usually fuses the two Mullerian ducts into a single uterine body, but fails to take place in the affected women who maintain their double Mullerian systems. A bicornuate uterus is a type of a uterine malformation where upper part of uterus forms two horns. The fusion process of upper part of Mullerian duct is altered. As a result, cranial part of the uterus becomes bifurcated. As Mullerian duct anomalies are of anatomic interest, this article discusses epidemiology, embryological development, genetics of development and malformation and lastly various classifications based on Mullerian duct development. Pregnancy in bicornuate uterus is usually of high risk with reproductive outcomes like recurrent abortions, preterm delivery or malpresentation. Classifying Mullerian duct anomalies bears merit because it correlates anatomic anomalies with arrests in morphogenesis. Establishing an accurate diagnosis is essential for planning treatment and management strategies.

A case of bilateral high termination of brachial artery was found during a cadaveric dissection at NEIGRIHMS, Meghalaya. The brachial artery of both arms in the upper l/3rd divided into superficial and deep branches, the superficial artery was observed anteromedial and the deep artery posteromedial in relation to the median nerve. In the cubital fossa, the deep artery passed beneath the pronator teres muscle to give common interosseous artery which divided into anterior and posterior interosseous branches. The main trunk followed normal ulnar arterial course. In both the arms, the superficial branch of brachial artery remained lateral to the median nerve to reach the cubital fossa where it passed deep to the bicipital aponeurosis and descended just beneath the brachioradials muscle, following the normal course of radial artery. These developmental variations were thoroughly discussed and compared with previously published findings with their clinical importance.

Posterior cerebral artery (PCA),terminal branch of basilar artery join the posterior communicating artery to complete the circle of Willis. The morphological variations of posterior segment of the circle of Willis are much of importance in the diagnosis & treatment of different cerebrovascular diseases.In a series of anatomical dissections of the cerebral arterial territory in 30 cadaveric brain specimens,an important variation of the precommunicating segment of the posterior cerebral artery PI was found. In this variation, an embryonic derivation of the posterior cerebral artery from the internal carotid artery (ICA) known as foetal type posterior cerebral artery was seen. This type of variation may lead to the appearance and severity of syndromes of vascular insufficiency in adults.

Intussusception is rare in adults. It accounts for 5 to 10% of all intussusceptions and 1% of all bowel obstructions. It has a definite lead point in the form of either a lesion in the bowel wall or intraluminal, which alters the normal peristalsis and may lead to an invagination. It may present as an acute, intermittent or chronic problem and thus making its pre-operative diagnosis difficult. The symptoms are usually those of bowel obstructions which include nausea, vomiting, abdominal pain with or without melena and it depends on the causative lesions. Ultrasound and CT scans are the two most important radiological methods used in the diagnosis of intussusceptions. Surgical resection of the intussuscepted mass without reduction and end to end anastomosis is the preferred line of treatment in adults, because most of the enteric intussusceptions are associated with malignancy. In this report, we present a case of jejuno - jejunal intussusception in a dissection hall cadaver and analyze its incidence, etio-pathogenesis, classification, symptomatology, importance of imaging studies in the diagnosis and the therapeutic interventions in detail.

Ectopic gallbladder or anomalous position of the gallbladder is a rare congenital anomaly. Knowledge and awareness of this anomaly is important as it may predispose to various gallbladder diseases and may lead to diagnostic confusion. Here we present a case of a rare variant of ectopic gallbladder - transverse or horizontal position of the gallbladder in a still born male fetus observed during routine fetal autopsy.

Chromosomal instability syndromes are a special group of disorders of cytogenetic interest which comprises of several rare, autosomal recessive conditions. Following exposure to sunlight, excessive chromosomal instability, breakage, defective nucleotide excision repair in DNA, defective apoptosis and increased susceptibility to neoplasia occurs. Xeroderma pigmentosum (XP) is characterised by the presence of chromosomal breakages, associated with increased frequency of sister chromatid exchanges. This is a case report of a 6 year old, male child having XP with dermal and ocular manifestations. Chromosomal breaks in chromosomal spread are seen. If it occurs in families, consanguinous marriages should be avoided; appropriate genetic counselling suggested and simple sun guarding techniques with appropriate protection from UV exposure can reduce the morbidity in these patients.