Hippocampus and its involvement in Alzheimer's disease: a review.

Hippocampus is the significant component of the limbic lobe, which is further subdivided into the dentate gyrus and parts of Cornu Ammonis. It is the crucial region for learning and memory; its sub-regions aid in the generation of episodic memory. However, the hippocampus is one of the brain areas affected by Alzheimer's (AD). In the early stages of AD, the hippocampus shows rapid loss of its tissue, which is associated with the functional disconnection with other parts of the brain. In the progression of AD, atrophy of medial temporal and hippocampal regions are the structural markers in magnetic resonance imaging (MRI). Lack of sirtuin (SIRT) expression in the hippocampal neurons will impair cognitive function, including recent memory and spatial learning. Proliferation, differentiation, and migrations are the steps involved in adult neurogenesis. The microglia in the hippocampal region are more immunologically active than the other regions of the brain. Intrinsic factors like hormones, glia, and vascular nourishment are instrumental in the neural stem cell (NSC) functions by maintaining the brain's microenvironment. Along with the intrinsic factors, many extrinsic factors like dietary intake and physical activity may also influence the NSCs. Hence, pro-neurogenic lifestyle could delay neurodegeneration.

The Paracondylar Skull Base: Anatomical Variants and Their Clinical Implications.

AIM: The knowledge of the vasculature around the paracondylar region is important in neurosurgical procedures such as the paracondylar and lateral supracondylar approaches. The objectives of the present study were to determine the prevalence of paracondylar emissary foramina in the adult skull bases and to study the morphology of condylar canals and hypoglossal canals. MATERIAL AND METHODS: The present study included 48 adult human skulls that were obtained from the gross anatomy laboratory of our institution. The paracondylar region was macroscopically observed for the variant foramina, canals and grooves. RESULTS: It was observed that the paracondylar emissary foramen was present in 16 skulls (33.3%). The foramen was found bilaterally in 7 skulls (14.6%) and unilaterally in 9 skulls (18.7%). The hypoglossal canal was single in 35 (72.9%) skulls, double in 11 skulls (22.9%), and triple in 2 skulls (4.2%). The paracondylar process (2.1%) and the paracondylar groove (2.1%) were seen in 1 skull each. The posterior condylar canal was found to be patent in 19 (39.6%) skulls. CONCLUSION: The present study observed that, the paracondylar emissary vein is not rare in occurrence as it is observed in 33.3% of cases. The identification of the paracondylar emissary veins and accessory vessels is important to avoid dangerous bleeding during the surgery. The morphological knowledge of the foramina around the paracondylar region is enlightening to the chiropractors, neurosurgeons and radiologists.

Morphology and topography of the parietal emissary foramina in South Indians: an anatomical study.

The objectives of the present study were to study the prevalence of the parietal emissary vein in adult South Indian population and to study the distance of foramen from the sagittal suture. There were 58 adult human skulls in the present study which were available at the anatomy department of our institution. The study included 116 parietal bones which have been observed macroscopically for the number, prevalence and topography of the emissary foramen. The emissary foramen was present in 83 parietal bones (71.5%) of the present study. It was present at the junction between the middle 1/3 and posterior 1/3 region of the parietal bone. The foramen was observed solitary in 73 parietal bones (62.9%), double in 8 bones (6.9%), and triple in 2 parietal bones (1.7%). The foramen was not observed in 33 parietal bones (28.4%). The bilateral absence of parietal emissary foramen was seen in 7 skulls (12.1%). It was absent unilaterally in 19 skulls (32.7%). The accessory foramina were seen in only 8 skulls (13.8%). The mean distance of the foramen from the sagittal suture was 6.7±2.9 mm and 6.8±2.8 mm on the right and left sides respectively. The prevalence of parietal emissary vein in the present study was 71.5%. The present study has observed important data about the morphology and morphometry of the parietal emissary vein in South Indian population. The identification of parietal emissary veins and accessory veins is important in the operation room to prevent the blood loss.

Effect of sildenafil-induced nitric oxide on the histomorphology of cardiomyocytes in male rats.

INTRODUCTION: Although sildenafil citrate, one of the selective phosphodiesterase-5 (PDE5) inhibitors, is considered the best treatment for erectile dysfunction, studies have shown that it has also a beneficial effect on a variety of cardiovascular conditions. In spite of reports of a significant protective effect of sildenafil against necrosis in intact hearts, there are also contradictory reports regarding its beneficial effect on the heart. Since there are not enough reports regarding the histomorphological changes in the cardiomyocytes after exposure to sildenafil citrate, the present study was conducted to observe the same along with other biochemical parameters. MATERIALS AND METHODS: Adult male albino rats of Wistar strain were used in the present study. The animals were divided into a control group and two experimental groups containing six rats each. The animals were treated with a solution of sildenafil citrate dissolved in distilled water. Histomorphological changes were observed by light microscopy and the levels of nitric oxide (NO) and PDE in the heart were measured by spectrophotometry. RESULTS: It was observed that animals treated with sildenafil citrate showed a highly significant increase in NO and a decrease in PDE level, but the histological architecture of the cardiomyocytes did not show much change other than a slightly elongated and swollen nucleus. CONCLUSIONS: This study shows that sildenafil citrate at low dosage is well tolerated by cardiac muscle cells, but as dosage increases, it may become detrimental through its NO and PDE activity.

Morphological analysis and morphometry of the foramen magnum: an anatomical investigation.

AIM: The objectives were to study the morphology of the foramen magnum in dry skulls and to evaluate its antero-posterior diameter, transverse diameter and the foramen magnum index. MATERIAL AND METHODS: The foramen magna of 53 dry human cadaver skulls that were obtained from the neuroanatomy laboratory were examined. Different shapes of the foramen magnum were macroscopically noted and classified. The antero-posterior and transverse diameters were measured and the average foraminal index was calculated. RESULTS: The foramen magnum shapes were determined as a round shape in 22.6% of cases, egg shape in 18.9%, tetragonal in 18.9%, oval in 15.1%, irregular in 15.1%, hexagonal in 5.6% and pentagonal in 3.8% of the cases. In 20.7% of skulls, the occipital condyle was observed to protrude into the foramen. The mean antero-posterior and transverse diameter of the foramen magnum was determined as 31 ± 2.4 mm and 25.2 ± 2.4 mm respectively. The average foramen magnum index was 1.2 ± 0.1. CONCLUSION: The present study has determined the various shapes of foramen magnum and its morphometry. The data obtained may be of useful to the neurosurgeon in analyzing the morphological anatomy of craniovertebral junction. The findings are also enlightening for the anthropologists, morphologists and clinical anatomists.

Morphometric study of the humerus segments in Indian population / Estudio morfométrico de los segmentos del húmero en población india

The aim of the present study was to obtain the measurements of the different humerus segments and to estimate the length of humeri from them. For this purpose 100 (51 left and 49 right) sex-aggregated, adult dry humerus from Indian population, were taken to analyze the morphometric details of the humerus segments. The distance between five different segments viz: most proximal point of the humeral head and greater tuberosity (HA), head of the humerus and surgical neck of humerus (HB), proximal and distal point of olecranon fossa (HC), the distal point of olecranon fossa and trochlea of humerus (HD), proximal point of olecranon fossa and distal point of trochlea of humerus (HE) and finally the maximum length of humerus (HL) were obtained by means of an osteometrical board and an analogical caliper. Simples linear regressions (p < 0.01) were made to correlate each segment with the total length of the humerus. Positive results were obtained in segments HB and HE of right humerus. Regressions formulae were obtained to define these estimative. In conclusion, our study demonstrated that length of the humerus can be estimated from measures of different segments of humerus and this study helps in forensic, anatomic and archeological cases in order to identify unknown bodies and to determine stature of the individual and as well as for the orthopedic surgeons for the treatment of proximal and distal humerus fractures and for their reconstruction.

El objetivo del estudio fue obtener las medidas de diferentes segmentos del húmero y calcular la longitud del húmero a partir de ellos. Fueron seleccionados 100 (51 izquierdos y 49 derechos) húmeros adultos secos, separados por sexo, de población india para analizar los detalles morfométricos de los segmentos dle hueso. La distancia entre cinco segmentos diferentes fueron establecidos: punto más proximal de la cabeza humeral y la tuberosidad mayor (HA), cabeza del húmero y cuello quirúrgico del húmero (HB), punto proximal y distal de la fosa olecraneana (HC), punto distal de la fosa olecraneana y la tróclea del húmero (HD), punto proximal de la fosa olecraneana y punto distal de la tróclea del húmero (HE) y, finalmente, la longitud máxima del húmero (HL) medidas obtenidas por medio de una tabla osteométrica y un caliper análogo. Se realizaron regresiones lineales simples para correlacionar cada segmento con la longitud total del húmero. Se obtuvieron resultados positivos en los segmentos de HB y HE de húmero derecho. Fórmulas de regresión se obtuvieron para definir estimativos. En conclusión, nuestro estudio demostró que la longitud del húmero puede estimarse a partir de las medidas de los diferentes segmentos del hueso, ayudando en casos forenses, anatómicos y arqueológicos con el fin de identificar cuerpos desconocidos o para determinar la estatura de la persona, así como a cirujanos ortopédicos para el tratamiento de las fracturas proximales y distales del húmero o para su reconstrucción.

A morphometric study of foramen ovale.

AIM: To note the morphological variations and morphometric details of foramina ovale in dry adult skulls of Indian origin. MATERIAL AND METHODS: 82 dry adult human skulls of unknown sex and of Indian origin were obtained and variations in appearance and number of foramen ovale were noted. The length and width of the foramina ovale of both sides were determined using digital Vernier calipers and area (A) was also calculated and analyzed. RESULTS: Out of 82 adult skulls, the values for the right side was 7.64 ± 1.194 mm, 5.128 ± 0.827 mm and 30.808 ± 7.545 mm2 and for the left side the values was 7.561 ± 1.123 mm, 5.244 ± 0.950 mm and 31.310 ± 8.262 mm2 respectively, for the mean length, width and area of the foramen ovale. The shape of foramen was typically ovale in most of the skulls (56.70%) with some bony variations such as spine, tubercles etc. CONCLUSION: There was no statistically significant difference between the two sides in length, width and area of foramen ovale and there was a positive correlation between lengths and areas of both sides.

Extensor carpi radialis brevis origin, nerve supply and its role in lateral epicondylitis.

Lateral epicondylitis (LE) or tennis elbow has been the subject of concern during the last 60 years, but the pathogenesis of the LE remains unclear. The LE can be due to the tendinogenic, articular or neurogenic reasons. Numerous theories have been put fourth in the recent past, out of which one of the most popular theories is that the condition results from repeated contraction of the wrist extensor muscles, especially the extensor carpi radialis brevis (ECRB) which may compress the posterior branch of the radial nerve (PBRN) at the elbow during pronation. We studied 72 upper limbs (36 formalin-fixed cadaver) for the origin, nerve supply and the course of PBRN in relation to the ECRB as one of the goal for the present study. The possible presence of an arch of the ECRB around the PBRN was also observed and recorded. The nerve to ECRB was a branch from the radial nerve in 11 cases (15.2%); from the PBRN in 36 cases (50%) and from the superficial branch of the radial nerve in 25 cases (34.7%), respectively. The ECRB had a tendinous arch in 21 cases (29.1%); a muscular arch in 8 (11.1%) cases and the arch was absent in 43 cases (59.7%). When the ECRB had a tendinous or muscular arch around the PBRN, it may compress the same and this condition may worsen during the repeated supination and pronation as observed in tennis and cricket players. The presence of such tendinous or muscular arch should be considered by orthopedicians and neurosurgeons, while releasing the PBRN during LE surgery.

Palmar type of median artery as a source of superficial palmar arch: a cadaveric study with its clinical significance.

The superficial palmar arch (SPA) and its contributing arteries are highly variable. The palmar type of median artery (PMA) can be involved in the formation of the SPA by replacing the superficial palmar branch of the radial artery (RA) or the ulnar artery (UA). The present study was undertaken to investigate the presence of the PMA and its contribution in the formation of SPA in 42 cadavers (84 upper limbs) of Indian origin. When there was a PMA, its outer diameter was measured in the carpal tunnel. The PMA was found in 13 upper limbs (15.4%), and of these ten incidences (11.9%), the PMA took part in the formation of SPA, and in three instances (3.5%), the PMA did not make up part of the SPA. Out of the ten cases in which the PMA contributed to the formation of SPA, in six cases (7.1%), the PMA anastomosed with the UA; in three cases (3.5%), the PMA anastomosed with both the UA and the RA, and in one incidence (1.1%), the PMA joined the arteria radialis indicis (deep branch of the RA) to complete the SPA. The outer diameters of the median arteries varied between 0.8 and 2.6 mm with the mean value of 1.7 mm. The present study concludes that the median-ulnar type of SPA was the most common type of SPA when the PMA was encountered as a source of superficial arterial arcade of the hand, followed by the radial-median-ulnar type. The vascular patterns found in this study are important to hand surgeons. The present study of PMA origin, course, and its contribution to the SPA will add to the existing knowledge of the vascular anatomy of forearm and hand.

Variation and clinical significance of extensor pollicis brevis: a study in South Indian cadavers.

BACKGROUND: de Quervain's disease is a condition in which there is pain in the radial styloid process caused by stenosing tenosynovitis of the abductor pollicis longus (APL) or/and extensor pollicis brevis (EPB) tendons in the first extensor compartment of the wrist. In this study we studied variations in the tendons of the EPB in the first extensor compartment and its site of insertion. METHODS: One hundred fifty six upper limbs from adult cadavers of south Indian origin were dissected to observe the number of EPB tendons and the presence of an osseo-fibrous septum in the first extensor compartment of the wrist. RESULTS: The EPB had a single tendon in 133 limbs, double tendons in 17 limbs and triple tendons in only 6 limbs. The EPB was present in all of the upper limbs in our study. In 34.6% of cases, the tendons of the EPB were separated from the tendons of APL by an osseo-fibrous septum in the first extensor compartment. CONCLUSION: Variation in the number of EPB tendons and site of insertion should be taken into consideration by clinicians and surgeons when performing surgical decompression of the first extensor compartment of the wrist in de Quervain's syndrome. Surgical failure may occur due to overlooking variations in EPB tendons or septation of the first extensor compartment.

Case report of high origin of radial, ulnar, and profunda brachii arteries, its clinical implications and review of the literature / Relato de caso de origem alta das artérias radial, ulnar e braquial profunda, suas implicações clínicas e revisão de literatura

Arterial variations in the arm are of potential clinical implications as it is a frequent site of injury and also involved in many surgical and invasive procedures. During a dissection of the right upper extremity, an abnormal high origin of the radial and ulnar arteries was found. The brachial artery had a very short segment without any branches, divided into the radial and ulnar arteries at the upper third of the arm. The course and branching pattern of these radial and ulnar arteries in the arm are discussed. It was also observed that the profunda brachii artery was represented by two separate branches arising from the posterior circumflex humeral artery. Accurate knowledge of these variation patterns is of considerable clinical importance in the conduct of reparative surgeries around the shoulder and fracture management of the humerus. These additional data of arterial anomalies to contemporary anatomical literature are of interest to clinicians, in particular vascular and plastic surgeons and radiologists.

As variações arteriais no braço têm potenciais implicações clínicas já que o braço é um sítio de lesões frequentes, além de estar envolvido em muitos procedimentos cirúrgicos e invasivos. Durante a dissecção da extremidade superior direita, uma origem alta anormal das artérias radial e ulnar foi encontrada. A artéria braquial apresentava um segmento muito curto sem quaisquer ramos, dividindo-se nas artérias radial e ulnar no terço superior do braço. O curso e o padrão de ramificação das artérias radial e ulnar no braço são discutidos. Também se observou que a artéria braquial profunda estava representada por dois ramos separados, surgindo da artéria umeral circunflexa posterior. O conhecimento preciso sobre esses padrões de variação é de considerável importância na realização de cirurgias reparadoras na região do ombro e no manejo de fraturas de úmero. Estes dados adicionais sobre as anomalias arteriais para a literatura anatômica contemporânea são de grande interesse para os médicos, especialmente para cirurgiões plásticos e vasculares e radiologistas.

Co-existence of superficial brachio-ulno-radial arterial pattern and persistent median artery.

The arteries of the upper limbs are situated in a deep plane and are the favourable sites for intra-arterial cannulation. During routine dissection of the left upper limb of a 52-year-old female cadaver, we observed a superficial arterial pattern which was of superficial brachio-ulno-radial type. The right upper limb of the same individual did not show any abnormal arterial pattern. This superficial arterial system was also associated with a palmar type of median artery. The clinical significance of the anomalous arterial system of the upper limb is discussed.

Variability in the origin of the obturator artery.

INTRODUCTION: General surgeons dealing with laparoscopic herniorrhaphy should be aware of the aberrant obturator artery that crosses the superior pubic ramus and is susceptible to injuries during dissection of the Bogros space and mesh stapling onto Cooper's ligament. The obturator artery is usually described as a branch of the anterior division of the internal iliac artery, although variations have been reported. MATERIALS AND METHODS: The present study was conducted on 98 pelvic halves of embalmed cadavers, and the origin and course of the obturator artery were traced and noted. RESULTS: In 79% of the specimens, the obturator artery was a branch of the internal iliac artery. It branched off at different levels either from the anterior division or posterior division, individually or with other named branches. In 19% of the cases, the obturator artery branched off from the external iliac artery as a separate branch or with the inferior epigastric artery. However, in the remaining 2% of the specimens, both the internal and the external iliac arteries branched to form an anastomotic structure within the pelvic cavity. CONCLUSION: The data obtained in this study show that it is more common to find an abnormal obturator artery than was reported previously, and this observation has implications for pelvic surgeons and is of academic interest to anatomists. Surgeons dealing with direct, indirect, femoral, or obturator hernias need to be aware of these variations and their close proximity to the femoral ring.

Origin of the sinoatrial and atrioventricular nodal arteries in South Indians: an angiographic study.

BACKGROUND: To study the arterial supply of the conducting system and its correlation with the dominance of the coronary arteries in the South Indian population. OBJECTIVE: To determine angiographically the origins of the sinoatrial nodal artery (SAna) and atrioventricular nodal artery (AVna) in Indians. METHODS: The study included 300 consecutive patients (114 females, 186 males; mean age, 55 years) living in the southern coastal region of India, who underwent coronary angiography either for the symptoms of chest pain, angina pectoris or positive Treadmill Test. The angiograms contained both coronary arteries (right and left) in the right and left anterior oblique position. The origin of SAna and AVna from the coronary arteries was observed and correlated with the arterial dominance. RESULTS: The SA (sinoatrial) node was supplied by the right coronary artery (RCA) in 53% of the cases, by the circumflex (Cx) branch of left coronary artery (LCA) in 42.66%, and by both coronary arteries in 4.33% of cases. The AV (atrioventricular) node was also more often supplied by the RCA (72.33% of cases) than by the Cx branch of the LCA (27.66%), and surprisingly in none of the cases was this node supplied by both coronary arteries. CONCLUSION: The results of the present study may help cardiac surgeons, particularly in surgeries related to certain valvular disorders, due to the proximity of the nodal branches to the valve complex.

Origem das artérias dos nós sinoatrial e atrioventricular em população do sul da Índia: um estudo angiográfico / Origin of the sinoatrial and atrioventricular nodal arteries in South Indians: an angiographic study / Origen de las arterias de los nódulos sinusal y atrioventricular en población del Sur de la India: un estudio angiográfico

Fundamento: Estudar o suprimento arterial do sistema condutor e sua correlação com a dominância das artérias coronárias em população do sul da Índia. Objetivo: Determinar angiograficamente as origens da artéria do nó sinoatrial (AnSA) e artéria do nó atrioventricular (AnAV) em indianos.Métodos: O estudo incluiu 300 pacientes consecutivos (114 do sexo feminino e 186 do sexo masculino; idade média, 55 anos), habitantes da região costeira ao sul da Índia, submetidos a cineangiocoronariografia devido a sintomas como dor no peito, angina pectoris ou teste ergométrico positivo. As angiografias incluíram ambas as artérias coronárias (direita e esquerda) em posição oblíqua anterior direita e esquerda. A origem da AnSA e AnAV a partir das artérias coronárias foi observada e correlacionada à dominância arterial. Resultados: O nó SA (sinoatrial) recebeu suprimento pela artéria coronária direita (ACD) em 53% dos casos, pelo ramo circunflexo (Cx) da artéria coronária esquerda (ACE) em 42,66% dos casos, e em 4,33% dos casos esse nó foi irrigado por ambas as artérias coronárias. O nó AV (atrioventricular) também recebeu suprimento sanguíneo com mais frequência da ACD (72,33% dos casos) do que do ramo Cx da ACE (27,66%). Surpreendentemente, em nenhum caso este nó recebeu suprimento de ambas as artérias coronárias. Conclusão: Os resultados do presente estudo podem auxiliar os cirurgiões cardíacos, sobretudo em cirurgias relacionadas a valvopatias, devido à franca proximidade entre os ramos nodais e o complexo valvar.

Background: To study the arterial supply of the conducting system and its correlation with the dominance of the coronary arteries in the South Indian population. Objective: To determine angiographically the origins of the sinoatrial nodal artery (SAna) and atrioventricular nodal artery (AVna) in Indians. Methods: The study included 300 consecutive patients (114 females, 186 males; mean age, 55 years) living in the southern coastal region of India, who underwent coronary angiography either for the symptoms of chest pain, angina pectoris or positive Treadmill Test. The angiograms contained both coronary arteries (right and left) in the right and left anterior oblique position. The origin of SAna and AVna from the coronary arteries was observed and correlated with the arterial dominance.Results: The SA (sinoatrial) node was supplied by the right coronary artery (RCA) in 53% of the cases, by the circumflex (Cx) branch of left coronary artery (LCA) in 42.66%, and by both coronary arteries in 4.33% of cases. The AV (atrioventricular) node was also more often supplied by the RCA (72.33% of cases) than by the Cx branch of the LCA (27.66%), and surprisingly in none of the cases was this node supplied by both coronary arteries. Conclusion: The results of the present study may help cardiac surgeons, particularly in surgeries related to certain valvular disorders, due to the proximity of the nodal branches to the valve complex.

Fundamento: Estudiar el suministro arterial del sistema conductor y su correlación con la dominancia de las arterias coronarias en población del Sur de la India. Objetivo: Determinar angiográficamente los orígenes de la arteria del nódulo sinusal (AnSA) y la arteria del nódulo atrioventricular (AnAV) en indios. Métodos: El estudio incluyó 300 pacientes consecutivos (114 del sexo femenino y 186 del sexo masculino; edad promedio, 55 años), habitantes de la región costera al Sur de la India, sometidos a cineangiocoronariografía debido a síntomas como dolor en el pecho, angina pectoris o test ergométrico positivo. Las angiografías incluyeron ambas arterias coronarias (derecha e izquierda) en posición oblicua anterior derecha e izquierda. El origen de la AnSA y AnAV a partir de las arterias coronarias se observó y se correlacionó con la dominancia arterial. Resultados: El nódulo SA (sinusal) recibió suministro por la arteria coronaria derecha (ACD) en el 53% de los casos, por la rama circunfleja (Cx) de la arteria coronaria izquierda (ACI) en el 42,66% de los casos, y en el 4,33% de los casos este nódulo fue irrigado por ambas arterias coronarias. El nódulo AV (atrioventricular) también recibió suministro sanguíneo con más frecuencia de la ACD (72,33% de los casos) que la rama Cx de la ACI (27,66%). Sorprendentemente, en ningún caso este nódulo recibió suministro de ambas arterias coronarias.Conclusión: Los resultados del presente estudio pueden auxiliar a los cirujanos cardíacos, sobre todo en cirugías relacionadas a valvulopatías, debido a la franca proximidad entre las ramas nodales y el complejo valvular.

Supratrochlear foramen of the humerus: an anatomico-radiological study with clinical implications.

BACKGROUND: The supratrochlear foramen (STF) of the humerus has been a neglected entity in standard anatomy and orthopaedics text-books. The knowledge of the presence of STF in a humerus may be important for preoperative planning for treatment of supracondylar fractures. The presence of STF may also result in erroneous interpretation of radiographs. METHODS: The STF was studied in detail in 384 (220 left side and 164 right side) human dried humeri of unknown sex and age. The topographical anatomy of the STF was studied in detail, morphometric measurements were taken, and the specimens were photographed. The humerus was also taken for radiological assessment of the STF and supratrochlear septum. RESULTS: Out of the 384 bones studied, 132 cases (34.3%) showed the presence of STF. The STF was oval, round, and triangular in shape in 123, 7, and 2 cases, respectively. The mean length of the transverse diameter for supratrochlear foramen was 6.55 mm and 5.99 mm on the left and right sides, respectively. The mean length of the vertical diameter for STF was 4.85 mm and 3.81 mm on the left and right sides, respectively. Most of the bones that had no STF showed a translucency of septum, in 56.7% of the bones. CONCLUSIONS: The results of our study show that STF is more common on the right side, with the oval shape being more common. The respective sides did not exhibit any statistical significant differences. Presence of STF may be important for anthropological, clinical, and academic purpose.

Morphology of the lacrimal sac and nasolacrimal duct in adult human cadaver.

The lacrimal sac (LS) is a dilated structure that lies in the lacrimal fossa, and the nasolacrimal duct (NLD) is the continuation of LS from its neck up to the inferior meatus of the nose. A study of 50 specimens of formalin-fixed adult cadavers of both sexes of Indian origin was conducted. The morphological features like length and breadth of LS and NLD, along with the histology of LS has been observed. The mean length of LS and NLD on the right side was 10.5 mm (1.04) and 16 mm (2.6) respectively, whereas the mean breadth of the above structures, on the right side was 6 mm (0.63) and 5.66 mm (0.81) respectively. The mean length of LS and NLD on the left side was 10.57 mm (1.13) and 16.42 mm (2.29), whereas, the mean breadth of the same structure on the left side was 6.71 mm (0.95) and 5 mm (0.81) respectively. The sides did not show any significant statistical difference but when the correlation between the length and breadth of LS is considered, significance was observed in the lacrimal sac of the left side. No variations were observed in the gross structure of LS and NLD. Microscopic study showed the presence of elastic fibers in LS. The importance of LS and NLD is that the blockage of this lacrimal passage is the most common cause of epiphora (watering of the eye). The presence of elastic fibers in this study confirms the hypothesis that the sac elasticity may perform a dynamic role, in forceful evacuation of lacrimal fluid in reverse direction (Tab. 2, Fig. 3, Ref. 10). Full Text (Free, PDF) www.bmj.sk.