Roqueline A. G. M. F. Aversi-Ferreira

Morphometric and statistical analysis of the palmaris longus muscle in human and non-human primates.

The palmaris longus is considered a phylogenetic degenerate metacarpophalangeal joint flexor muscle in humans, a small vestigial forearm muscle; it is the most variable muscle in humans, showing variation in position, duplication, slips and could be reverted. It is frequently studied in papers about human anatomical variations in cadavers and in vivo, its variation has importance in medical clinic, surgery, radiological analysis, in studies about high-performance athletes, in genetics and anthropologic studies. Most studies about palmaris longus in humans are associated to frequency or case studies, but comparative anatomy in primates and comparative morphometry were not found in scientific literature. Comparative anatomy associated to morphometry of palmaris longus could explain the degeneration observed in this muscle in two of three of the great apes. Hypothetically, the comparison of the relative length of tendons and belly could indicate the pathway of the degeneration of this muscle, that is, the degeneration could be associated to increased tendon length and decreased belly from more primitive primates to those most derivate, that is, great apes to modern humans. In conclusion, in primates, the tendon of the palmaris longus increase from Lemuriformes to modern humans, that is, from arboreal to terrestrial primates and the muscle became weaker and tending to be missing.

Anatomical Analysis of Thumb Opponency Movement in the Capuchin Monkey (Sapajus sp)

Capuchin monkeys present a wide variety of manipulatory skills and make routine use of tools both in captivity and in the wild. Efficient handling of objects in this genus has led several investigators to assume near-human thumb movements despite the lack of anatomical studies. Here we perform an anatomical analysis of muscles and bones in the capuchin hand. Trapezo-metacarpal joint surfaces observed in capuchins indicate that medial rotation of metacarpal I is either absent or very limited. Overall, bone structural arrangement and thumb position relative to the other digits and the hand’s palm suggest that capuchins are unable to perform any kind of thumb opponency, but rather a ‘lateral pinch’ movement. Although the capuchin hand apparatus bears other features necessary for complex tool use, the lack thumb opposition movements suggests that a developed cognitive and motor nervous system may be even more important for high manipulatory skills than traditionally held.

Historic and Teaching Aspects of Anatomy and Cebus Genus Role in Contemporary Anatomy

La anatomia es la ciencia que estudia el cuerpo y una disciplina basica en ciencias de la salud y biologicas, indispensables para los estudiantes que tratan esta materia, teniendo ademas, un importante papel en la comparacion de las especies. Actualmente, la anatomia esta en una crisis academica y cientifica. Por otra parte, recientemente, el numero de articulos y revisiones en la educacion en ciencias de la salud han aumentado considerablemente. Las disciplinas pre-clinicas son esenciales para todos los cursos de salud y ciencias biologicas, entre ellas, la anatomia es considerada como la base de las ciencias morfologicas. Por esa razon, a lo largo de la historia, la anatomia ha sido considerada como una base de conocimiento de los hechos que deben ser aprendidas en su totalidad. La historia de la anatomia ha demostrado que la ensenanza en esta area se ve facilitada por el uso de la diseccion de animales. En ausencia de cadaveres humanos, es posible utilizar los animales para la diseccion, generando asi beneficios para los estudiantes. El objetivo de este trabajo fue recordar el pasado para entender que la anatomia es la base de la ciencia de la salud actual y darse cuenta de la importancia de la ensenanza de esta disciplina. Finalmente, es importante recordar que los investigadores algunas veces han llegado a conclusiones erroneas debido a la falta de conocimiento sobre temas anatomicos.

Reexamination of Statistical Methods for Comparative Anatomy: Examples of Its Application and Comparisons with Other Parametric and Nonparametric Statistics

Various statistical methods have been published for comparative anatomy. However, few studies compared parametric and nonparametric statistical methods. Moreover, some previous studies using statistical method for comparative anatomy (SMCA) proposed the formula for comparison of groups of anatomical structures (multiple structures) among different species. The present paper described the usage of SMCA and compared the results by SMCA with those by parametric test (t-test) and nonparametric analyses (cladistics) of anatomical data. In conclusion, the SMCA can offer a more exact and precise way to compare single and multiple anatomical structures across different species, which requires analyses of nominal features in comparative anatomy.

Comparative anatomical study of the leg's nerves of Cebus (barbed capuchins) with baboons, chimpanzees and modern humans

The anatomical comparative studies among the primates are important for the investigation of ethology, evolution, taxonomy, and comprehension of tools by hominoids. Especially the anatomical knowledge of Cebus contributes to conservation of the species, and to development of surgical procedures and clinical treatments of these animals, as they frequently are victims of automobile accidents. Recent anatomical studies came to a wrong conclusion regarding behavioral traits of Cebus, ascribed to few data available in previous literature. Therefore, to provide anatomical data and to support the other sciences related to anatomy, and to develop surgical and/or clinical procedures, we described the nerves of the legs of Cebus foccusing on their position and trajectory, as wll as innerved muscles, and compared these results with those of humans and other primates. Eight adult capuchin specimens were used for this study. The anatomical comparative study of the legs nerves of Cebus demonstrated that, in general, structural organization of the nerves is similar among the four primates analyzed here (Cebus, chimpanzees, baboons and humans), which might be attributed to the fact that the all four primates have similar body structures. However, nerve trajectory and muscles innervation in Cebus was more similar to baboons.

Teaching Embryology Using Models Construction in Practical Classes

Recientemente, el plan de estudios y las metodologias educativas asociadas a los cursos de ciencias de la salud estan siendo revisados y adaptados. Ciencias pre-clinicas tales como la Anatomia y la Embriologia son tambien sometidas a cambios. En los cursos de Embriologia Humana, es comun el uso de modelos para representar las diferentes fases del desarrollo, y asi facilitar el aprendizaje, ya que los estudiantes pueden ver y tocar los modelos, asi se realiza la obtencion de conocimientos por medio de analogias. El proposito del presente estudio fue investigar si la construccion de modelos por parte de los estudiantes, durante las clases practicas de Embriologia, mejora o facilita su aprendizaje. Despues de un ano, 60 estudiantes respondieron a un cuestionario con nueve preguntas objetivas, incluidos los espacios para sugerencias y observaciones. De acuerdo con las respuestas de los estudiantes, la construccion de modelos han contribuido a su aprendizaje.

Comparative anatomy of the arm muscles of the Japanese monkey (Macaca fuscata) with some comments on locomotor mechanics and behavior

The anatomical literature on the genus Macaca has focused mainly on the rhesus monkey. However, some aspects in the positional behaviors of the Japanese monkey may be different from those in rhesus monkey, suggesting that the anatomical details of these species are divergent.

Comparative Anatomy of the Pelvic Vessels in the Bearded Capuchin (Sapajus libidinosus) and Baboons, Apes and Modern Humans

Cebus/Sapajus has shown high cognitive and manipulatory behaviour as well as intermittent bipedalism. Although the function of the muscles and bones of this genus has been widely investigated, the arterial system that supports these tissues has not been studied in much detail, and a full description of the blood vessels of the pelvis is still missing. Therefore, we studied the vessels of the pelvis of Sapajus libidinosus in terms of their origin, distribution and muscle irrigation and compared them with those of other primates available in the literature. In general, the distribution pattern and origin of arteries in the pelvis of the bearded capuchin are more similar to those of baboons compared to other primates. This similarity may be because both have a tail, a similar body shape and use, preferentially, quadrupedal movement.

A Statistic Method for Anatomical and Evolutionary Analysis

Rules, formulas, and statistical tests have been widely used in studies that analyze continuous variables with the normal (Gaussian) distribution or defined parameters. Nevertheless, in some studies such as those in gross anatomy, only statistics with discrete or nominal variables are available. In fact, the existence or absence of an anatomical structure, its features and internal aspects, innervation, arterial and vein supplies, etc. can be analyzed as discrete and/or nominal variables. However, there have been no adequate methods, which allow transformation of data with qualitative/nominal variables in gross anatomy to those with quantitative variables. To resolve the issue, we have purposed a new method that allows, in order, descriptions based on numerical analyses, the statistical method for comparative anatomy (SMCA), and proposed the formula for comparison of groups of anatomical structures among different species that allows to infer evolutionary perspective. The important features of this method are as follows: (1) to allow to analyze numerical data, which are converted from discrete or nominal variables in morphological areas and (2) to quantitatively compare identical structures within the same species and across different species. The SMCA fills the lack of a specific method for statistical works in comparative anatomy, morphology, in general, and evolutional correlations.