Brains were obtained from 1000 medicolegal autopsy subjects of varying ages. The circle of Wills was examined at the base of the brain. The cerebral vessels were observed with regards to their origin, caliber and typical configuration. Variations were noted and grouped into different categories. Out of 1000 specimens examined, 452 (45.2%) conformed to the typical pattern. In the rest of the specimens (54.8%) there were variations in the circulus arteriosus. The circle was deficient in 32 (3.2%). The anterior cerebral artery was absent in 0.4%; hypoplastic in 1.7%; duplicated in 2.6%; triple in 2.3% and single in 0.9%. The anterior communicating artery was absent in 1.8%, duplicate in 10%, triplicate in 1.2% and plexiform in 0.4%. Multiplication of posterior cerebral artery was observed in 2.4% cases while it was hypoplastic in 10.6% brains. Posterior communicating artery was absent in 1% and hypoplastic in 13.2%. Seventy-four brains (7.4%) had multiple variations. Intracranial saccular aneurysm was present in 10 (1%). These figures are compared with the available literature. Persistence of some embryonic vessel that normally disappear, disappearance of vessels that would normally persist or sprouting of new vessels due to hemodynamic and genetic factors are the usual causes for such anomalies. These variations are discussed with regard to development and other hemodynamic factors.

The normal configuration of the arterial pattern at the base of the brain in rhesus monkeys, dogs, sheep, goats and rabbits is described. The length and diameter of all vessels of the circulus arteriosus cerebri are measured. Variations are compared in relation to that of the typical pattern present in humans. In rhesus monkeys, dogs and rabbits, the circle of Willis is almost similar to that in human beings except that in these animals, (i) the anterior cerebral arteries join each other to form a single median vessel; (ii) in dogs, rabbits, goats and sheep the anterior cerebellar artery is a branch of posterior cerebral artery, and (iii) in goats and sheep, a considerable length of the internal carotid artery contributes to the formation of circulus arteriosus while the posterior cerebral artery arises from the posterior communicating artery.

The present study highlights a three-dimensional orientation of subaxial cervical pedicle anatomy, while emphasizing the risks involved in the view of comparatively smaller values of pedicle dimensions of subaxial cervical vertebrae. This knowledge about typical cervical vertebrae, its pedicle and their adjacent neurovascular structures may enhance the safety of transpedicular screw insertion.

A total of 260 male subjects between 1 and 80 years of age of north-west region of India were studied with regard to morphometry of the ear lobule. The purpose of the present study was to obtain average values and range of measurements of several parameters of the ear lobule and the differences between right and left lobules. Female subjects were excluded from the study due to piercing. Various measurements of lobule were taken with the help of Vernier and Lange's calipers. The results of the aforementioned measurements were analyzed statistically using Student's t-test. The maximum length of the lobule increased appreciably between 6-15 years and 41-80 years. The breadth of the ear lobule increased up to the age of 15 years and was almost static between the ages of 16 and 40 years and increased again from 41 years onwards. Length of the lobule showed significant growth from the age group of 6-10 to 11-15, 21-40 to 41-60 and 41-60 to 61-80 years on the right side and 6-10 to 11-15 and 21-40 to 41-60 years on the left side. Breadth and thickness of ear lobule also showed statistically significant growth pattern in some age groups. On comparing the ear lobe dimensions with the studies available in other populations of the world, it was observed that north-west Indians have smaller ear lobules as compared to Caucasian and Japanese populations. In the present study, the frequency of attached (square) type of lobules was the maximum, followed by free (pendulous) type and tapering lobules. These findings were similar to those found among the Onge tribe of Andhra (India) and Newars of Nepal.