The shingled girl: Catherine Janet Hill and her contributions to embryology.

Catherine J. Hill is best remembered for her dedication to cataloguing the comprehensive embryological collection of her father J. P. Hill. Yet, her own research, during the interwar years, is little known. She made a significant contribution to interpreting the autonomic innervation of the gut, work that was presented to The Royal Society and earned her a PhD. Working in her father's laboratory, she then set about solving the sequence of secretions from the tubal epithelium and uterine glands that contributed the two layers of egg albumen and three shell layers of the monotreme egg. She was also the first to understand twinning in the marmoset and how two embryos came to share a single extraembryonic coelom, work that often is credited to J. P. Hill. Here. I explain how that happened and explore the context in which she and other female scientists worked at the time.

Ian Wilmut (1944-2023).

Embryologist who cloned Dolly the sheep.

Percepción de la Virtualización de la Asignatura de Anatomía Humana Normal y Embriología en Pandemia / Perception of the Virtualization of the Subject of Normal Human Anatomy and Embriology in a Pandemic

Debido a la pandemia y las restricciones en cuanto a la presencialidad, diferentes metodologías de aprendizaje debieron ser exploradas e implementadas para virtualizar los contenidos en la asignatura de Anatomía. El objetivo de este trabajo fue evaluar la percepción de los docentes y alumnos con respecto a las metodologías utilizadas en la virtualización de dicha asignatura. Estudio observacional- descriptivo, con enfoque cuantitativo. La población de estudio correspondió a una muestra por conveniencia constituida por 57 alumnos y 4 docentes pertenecientes a la asignatura de Anatomía Humana Normal y Embriología de la carrera de Odontología, Universidad Andrés Bello, sede Viña del Mar, dictada el año 2021. Dichos participantes contestaron un cuestionario validado que contemplaba preguntas cerradas con escala de Likert de 5 niveles, considerando las dimensiones de aprendizaje, motivación y rendimiento, y preguntas de calificación para conocer la percepción sobre las estrategias y recursos utilizados. Los alumnos perciben positivamente todos los recursos digitales, destacando el Manual de Anatomía Humana Normal, siendo el aprendizaje, la dimensión mejor evaluada. La estrategia activa mejor percibida en cuanto a las 3 dimensiones corresponde a método de casos. Por el contrario, las clases invertidas fueron percibidas negativamente en todas las dimensiones. En relación a los docentes, el recurso digital mejor percibido fue videos y cápsulas, destacando la dimensión motivación. Las estrategias activas mejor evaluadas fueron método de casos y clases invertidas. Pese a haber una percepción positiva con respecto a la virtualización, no hay concordancia entre las estrategias activas y recursos digitales mejor evaluados entre docentes y alumnos.

SUMMARY: As a result of the pandemic and the restrictions regarding in person attendance, different learning methodologies had to be explored and implemented to virtualize the contents in the Anatomy subject. The objective of this study was to evaluate the perception of teachers and students regarding the methodologies used in the virtualization of this subject. An observational-descriptive study with a quantitative approach was carried out. The study population was a convenience sample made up of 57 students and 4 teachers of the Normal Human Anatomy and Embryology subject of the Dentistry degree, Universidad Andrés Bello, Viña del Mar campus during 2021. These participants answered a validated questionnaire that included closed questions with a 5-level Likert scale, considering learning dimensions, motivation and performance, and qualifying questions to find out the perception of the strategies and resources used. Students positively perceive all digital resources, highlighting the Normal Human Anatomy Manual, with learning being the best evaluated dimension. The best perceived active strategy in terms of the 3 dimensions corresponds to the case method. In contrast, the inverted classes were perceived negatively in all dimensions. In relation to teachers, the best perceived digital resource was videos and capsules, highlighting the motivation dimension. The best evaluated active strategies were the case method and inverted classes. Despite having a positive perception regarding virtualization, there is no agreement between the best evaluated active strategies and digital resources among teachers and students.

Implementing a multi-colour genetic marker analysis technique for embryology education.

Embryology belongs to the basic sciences and is usually an integral part of the anatomy. The subject is traditionally taught by visual inspection of embryonic tissue slides stained with Haematoxylin and Eosin (H&E) to expose the dynamics of tissue histology as development proceeds. While combining in situ hybridization for gene expression analysis and immunostaining for protein expression analysis is an established technique for embryology research, the implementation of this tool in embryology teaching has not been described. The present study was conducted to assess the use of an online multi-colour gene expression analysis technique, alongside histological sections and diagrams, to improve students' understanding of embryology. The participants of this study were bachelor's students of Veterinary Medicine at the University of Khartoum. The method was also evaluated by distributing questionnaire items to Veterinary students via Google forms; subsequently, their responses were analysed qualitatively. The majority of students stated that the new technique was beneficial for their learning of embryology. The multi-colour images proved a more effective means for learning embryology than the traditional H&E image. Results from the students strengthen the belief in applying the multi-colour technique for better embryology course learning.

Kahoot© como estratégia de aprendizagem no ensino de ciências morfofuncionais: uma revisão integrativa / Kahoot© as a learning strategy in the teaching of morphofunctional sciences: an integrative review

Introdução: tecnologias digitais como as gamificações vem modernizando e inovando o processo de aprendizagem. Objetivo:agrupar, por meio de uma revisão de literatura, evidências científicas acerca da aplicabilidade do Kahoot© como estratégia de aprendizagem na disciplina de Ciências Morfofuncionais. Metodologia: os termos "anatomy", "histology", "embryology", "gamification", "kahoot", "Kahoot!", foram empregados nas bases de dados PubMed, Scopus, Bireme, Web of Science, Science Direct e Eric, utilizando operadores booleanos OR/AND. Foram estabelecidos como critérios de inclusão, artigos com delineamento do tipo experimental, observacional e revisões sistemáticas que descreveram a utilização do Kahoot© como ferramenta de ensino na disciplina de morfologia humana, publicados nos idiomas inglês, espanhol e português, no período de 2013 a 2021. Foram excluídos, artigos que utilizaram o Kahoot© em outras áreas do conhecimento e em outros componentes curriculares. Resultados: a amostra foi constituída por 337 artigos que, após leitura do título e resumo, foram submetidos aos critérios de inclusão e exclusão. Destes, 11 artigos foram elegíveis para o estudo. Discussão: o Kahoot© motiva o estudante, criando uma atmosfera divertida, favorecendo o trabalho colaborativo e o engajamento dos alunos em seu processo de aprendizagem. Elementos associados à gamificação foram vistos como responsáveis pela descontração e como agentes estressores. Conclusão: o Kahoot© possibilita um aprender divertido e dinâmico, porém, pesquisas que utilizem grupo controle e experimental são relevantes para verificar a efetividade do Kahoot© no ensino de morfologia a curto, médio ou longo prazo, potencializando os benefícios do seu uso em sala de aula.

Introduction:digital technologies such as gamifications have been modernizing and innovating the learning process. Objective: to group, through a literature review, scientific evidence about the applicability of Kahoot© as a learning strategy in the discipline of Morphofunctional Sciences. Methodology: the terms "anatomy", "histology", "embryology", "gamification", "kahoot", "Kahoot!" were employed in the PubMed, Scopus, Bireme, Web of Science, Science Direct and Eric databases, using Boolean OR/AND operators. Inclusion criteria articles with an experimental, observational design and systematic reviews were established that described the use of Kahoot© as a teaching tool in the discipline of human morphology, published in English, Spanish and Portuguese, from 2013 to 2021. Articles that used Kahoot© in other areas of knowlwdge and other curricular components were excluded. Results: the sample consisted of 337 articles that, after reading the title and abstract, were found in the searched databases. After reading the title and abstract, the articles are subject to the inclusion and exclusion criteria. Of these, 11 articles were eligible for the study. Discussion: the Kahoot© motivates the student, creating a fun atmosphere, favoring collaborative work and studente engagement in their learning process. Elements associated with gamification were seen as responsible for the relaxed and stressing agents. Conclusion: Kahoot© a fun and dynamic learning, however, research using control and experimental group is relevant to verify the effectiveness of Kahoot© in the teaching of morphology in the short, medium, or long term, enhancing the benefits of its use in the classroom use

Evaluation of the usage of YouTube videos about Histology and Embryology as an educational material.

The use of YouTube videos for educational purposes has been increasingly popular. The quality and accuracy of the information level of these videos should be checked by expert trainers. This study aims to evaluate the content, quality and functionality of YouTube videos on Histology and Embryology and to measure their educational usefulness. In the study, searches were performed using the keywords "Histology" and "Embryology" in the YouTube search tab. Quality and content were evaluated using the Video Power Index (VPI), modified DISCERN scale, JAMA and the Global Quality Scale (GQS). Videos were categorized by educational usefulness. SPSS software was used for statistical analysis. A statistically significant high correlation was observed between modified DISCERN scores and JAMA scores (r = 0.757, p < 0.001) and between modified DISCERN scores and GQS scores (r = 0.743, p < 0.001). A statistically significant high correlation was also determined between JAMA and GQS scores (r = 0.632, p < 0.001). GQS scores were weakly, negatively and significantly correlated with the number of comments (r = -0.302, p < 0.05) and dislikes (r = -0.325, p < 0.05). Based on GQS, the useful and non-useful videos differed significantly in terms of views, likes, dislikes, comments counts and days since upload (p < 0.05). Modified DISCERN and JAMA scores also differed significantly between the useful and non-useful videos (p < 0.001). Educational videos published for Histology and Embryology education on the internet will be more beneficial if they are prepared by expert educators from reliable information sources, by the current literature, and by scoring systems such as DISCERN, JAMA and GQS.

La ética médica necesita la difusión del profesor Gonzalo Herranz / Medical ethics needs the diffusion of professor Gonzalo Herranz

Quien ha conocido al Prof Gonzalo Herranz Rodríguez participa de un común sentir en el que se entre-mezclan respeto y admiración transmitidos desde una personalidad natural y sencilla. Generaba una nota-ble capacidad de atracción. En el amplio campo de la bioética ha dejado un ejemplo indeleble de apasiona-do y tenaz defensa de la verdad científica, tanto en las múltiples facetas que marcan la cotidianidad de laactuación médica respecto al enfermo, como en su claro liderazgo internacional cuando fue preciso señalardónde se encontraba la autenticidad en los hallazgos biológicos sobre los primeros estadios del embriónhumano que luego permiten garantizar la correcta actuación médica. Su tenaz esfuerzo en la búsqueda dela verdad científica junto a la defensa de una actitud de cercanía y de humanidad con el enfermo, proveníatanto de su rigor en el estudio de la enfermedad como en sus dotes de fina observación que le permitíanhallar soluciones, mezcla de ciencia y humanidad, a las mil incidencias de actuación médica. Por ello, se venecesaria la difusión de sus trabajos ya que constituyen una referencia que marca el nivel de calidad quees exigible para la correcta actuación médica.(AU)

Those who knew Prof. Gonzalo Herranz Rodríguez share a common feeling in which respect and ad-miration are intermingled, transmitted from a natural and simple personality. He generated a remarkablecapacity for attraction. In the broad field of bioethics he has left an indelible example of passionate andtenacious defence of scientific truth, both in the multiple facets that mark the daily life of medical actionwith respect to the sick, and in his clear international leadership when it was necessary to point out whereauthenticity was to be found in the biological findings on the first stages of the human embryo that la-ter enable correct medical action to be guaranteed. His tenacious effort in the search for scientific truth,together with his defence of an attitude of closeness and humanity towards the patient, stemmed bothfrom his rigour in the study of illness and his gifts of fine observation that allowed him to find solutions,a mixture of science and humanity, to the thousand incidences of medical action. For this reason, it is ne-cessary to disseminate his work, as it constitutes a reference that marks the level of quality that is requiredfor correct medical action.(AU)

Sperm origin impact on early human embryo kinetics / El origen del gameto paterno influye en la cinética embrionaria temprana

Introduction: Time-lapse imaging in embryology is a recent and developing technology, which not only allows constant embryo monitoring but is also a promising non-invasive tool for embryo selection, as it permits the annotation of the embryo's kinetics throughout early development. Several external factors together with patient characteristics are reported as affecting embryo kinetics. Controversy still exists regarding whether sperm origin affects the timing of the embryo's developmental events evaluated by time-lapse monitoring. The aim of this study is to examine the effect of sperm origin on embryonic kinetics in IVF cycles. Material and methods: A retrospective analysis of 161 IVF cycles between 2014 and 2020 were included. The morphokinetic parameters of 220 embryos obtained from couples with severe male factor infertility who underwent testicular sperm extraction (TESE), and 613 embryos from couples with fresh ejaculated spermatozoa were evaluated. Results: Statistically significant morphokinetic differences were observed between embryos from the TESE group compared to the normozoospermic embryos. In fact, 7 kinetic variables were eventually found to be relevant (p<.05). Conclusions: This study showed that embryos derived from testicular-retrieved spermatozoa presented delayed cell divisions, compared to ejaculated spermatozoa embryos.(AU)

Introducción: La tecnología time-lapse en embriología es una metodología de aplicación reciente en los laboratorios de fecundación in vitro (FIV), que además de la monitorización continua de los embriones, permite realizar anotaciones sobre la morfología y la cinética del desarrollo embrionario que pueden emplearse en la selección de embriones. Se ha descrito que la cinética de los embriones en cultivo varía en función de múltiples factores, como la estimulación ovárica, los medios de cultivo empleados, las condiciones de cultivo, etc. Se desconoce cuál es el efecto paterno en la cinética embrionaria y si este efecto depende del origen de los espermatozoides. El objetivo de este estudio es evaluar el efecto del origen de los espermatozoides sobre la cinética embrionaria en los ciclos FIV. Material y métodos: Para ello, se analizaron retrospectivamente 161 ciclos de FIV entre los años 2014 y 2020. Se incluyeron 220 embriones de parejas con infertilidad por factor masculino severo que se sometieron a una biopsia para la recuperación de esperma testicular (TESE) y 613 embriones derivados del eyaculado fresco de varones normozoospérmicos. Resultados: Se observaron diferencias estadísticamente significativas entre los embriones que se originaron en el grupo TESE, en comparación con los normozoospérmicos. De hecho, se encontraron siete variables cinéticas relevantes (p<0,05). Conclusiones: Este estudio muestra que los embriones derivados de espermatozoides recuperados por biopsia testicular presentan un patrón de división tardío, en comparación con los embriones provenientes de espermatozoides del eyaculado.(AU)

Human embryology science: which theoretical information do clinical embryologists need to know more about? A survey / Ciencia de la embriología humana: ¿Qué información teórica necesitan saber más los embriólogos clínicos? Una encuesta

SUMMARY: For the past decades, it has been apparent that assisted reproductive technologies along with clinical embryology have both propounded themselves triumphantly in the field of medicine. Although high-tech equipment and staff skills are crucial to the success of these breakthrough implementations, the pivot of these practices is updated, knowledgeable and competent technicians who excel in the field of human embryology. Crucially, the advancement of clinical embryology and its related fields depends on the meticulous training of clinical embryologists in practical skills as well as theoretical knowledge. Unfortunately, most aspects of reproductive medicine have no obligatory assembled curriculum. A lot more emphasis has been put on the clinical aspect of these sciences and training than its theoretical counterpart. Consequently, clinical embryologists continue to face difficulty in unifying the needed theoretical knowledge in these fields. Not only that, but they also struggle to shed a light on the advanced knowledge required to stand out as professionals. This study aimed to explore which theoretical information in the science of human embryology that embryologists need to know thoroughly about. The survey was conducted online (July 2021).

RESUMEN: Durante las últimas décadas, ha sido evidente que las tecnologías de reproducción asistida junto con la embriología clínica han demostrado un éxito importante en el area de la medicina. Si bien los equipos de alta tecnología y las habilidades del personal son cruciales para el éxito de estas implementaciones, el eje de estas prácticas son los técnicos actualizados, competentes y expertos en el campo de la embriología humana. Fundamentalmente, el avance de la embriología clínica y sus campos relacionados dependen de la formación meticulosa de los embriólogos clínicos en las habilidades prácticas y los conocimientos teóricos. Desafortunadamente, la mayoría de los aspectos de la medicina reproductiva no cuenta con un plan de estudios obligatorio. El énfasis se ha concentrado en el aspecto clínico y en el entrenamiento de estas ciencias más que en la contraparte teórica. En consecuencia, los embriólogos clínicos continúan enfrentando dificultades para unificar el conocimiento teórico necesario en estos campos. Este estudio tuvo como objetivo explorar qué información teórica importante en la ciencia de la embriología humana requieren los embriólogos. La encuesta de este trabajo se realizó en línea (julio de 2021).

Comprehensive guidance for human embryology, andrology, and endocrinology laboratories: management and operations: a committee opinion.

This document is a comprehensive guidance for human embryology, andrology, and endocrinology laboratories. Universal guidance applicable to all laboratories includes requirements and recommendations for accreditation and staffing in the United States, and specific guidance is included for each laboratory specialty.

The use of active methodologies for the teaching of human embryology: A systematic review.

Embryology is a basic science, of the medical curriculum and of the health area, it serves as a foundation for the understanding of the phenomena that occur in normal development and its alterations. Over the years, active methodologies have been increasingly used as innovative tools in the academic training of health professionals. In this work we aim, through an integrative review, to search for the active methodologies used in the teaching of embryology. The PICo strategy was used to form the guiding question, the results were presented through the Prisma Flow diagram. The databases consulted were PubMed, Embase, Scopus, Web of Science, Science Direct, Medline, Scielo and LILACS, searching for articles until the year 2021. Our results show that embryology is a science still to be explored in the field of methodologies active, few works were found, most using TBL or digital platforms; however, the authors agree that active methodologies are valuable tools in the teaching of embryology, capable of improving student motivation and engagement.

From Monsters to Malformations: Anatomical Preparations as Objects of Evidence for a Developmental Paradigm of Embryology, 1770-1850.

A common object found within medical museums is the developmental series: an arrangement of embryos depicting the transformation of an unremarkable blob into an anatomically organized and recognizable organism. The developmental series depicts a normative process, one where bodies emerge in reliable sequential stages to reveal anatomically perfect beings. Yet a century before the developmental series would become a visual model of embryological development, the very process of development itself was discerned through the comparative study of preserved human fetuses-specifically, those deemed "monstrous" or characterized as "malformations." This article examines how anatomically diverse fetal bodies were reformulated from singular curiosities into alternative developmental pathways whose characteristics testified to the laws of nature and to the primordial, physical relationship between humans and other species. In early nineteenth century Amsterdam, the father-son team of physicians Gerard and Willem Vrolik built up an internationally renowned anatomical museum famous especially for Willem's collection of fetal malformations. Physical preparations of fetal malformations play a central role in Willem's monumental handbook on developmental embryology: comparing human embryos against one another and the embryos of other species, Willem plots out a sequence of embryological development in which a body's form marks its place within the ever-unfolding natural order. In conversation with the literature on model organisms, this article explores how the "monstrous" gets standardized and, in doing so, contributes to the scientific production of a normative physiological process.

Exploring Visualisation for Embryology Education: A Twenty-First-Century Perspective.

Embryology and congenital malformations play a key role in multiple medical specialties including obstetrics and paediatrics. The process of learning clinical embryology involves two basic principles; firstly, understanding time-sensitive morphological changes that happen in the developing embryo and, secondly, appreciating the clinical implications of congenital conditions when development varies from the norm. Visualising the sequence of dynamic events in embryonic development is likely to be challenging for students, as these processes occur not only in three dimensions but also in the fourth dimensions of time. Consequently, features identified at any one timepoint can subsequently undergo morphological transitions into distinct structures or may degenerate and disappear. When studying embryology, learners face significant challenges in understanding complex, multiple and simultaneous events which are likely to increase student cognitive load. Moreover, the embryology content is very nonlinear. This nonlinear content presentation makes embryology teaching challenging for educators. Embryology is typically taught in large groups, via didactic lecture presentations that incorporate two-dimensional diagrams or foetal ultrasound images. This approach is limited by incomplete or insufficient visualisation and lack of interactivity.It is recommended that the focus of embryology teaching should instill an understanding of embryological processes and emphasise conceptualising the potential congenital conditions that can occur, linking pre-clinical and clinical disciplines together. A variety of teaching methods within case-based and problem-based curricula are commonly used to teach embryology. Additional and supplementary resources including animations and videos are also typically utilised to demonstrate complex embryological processes such as septation, rotation and folding.We propose that there is a need for embryology teaching in the twenty-first century to evolve. This is particularly required in terms of appropriate visualisation resources and teaching methodologies which can ensure embryology learning is relevant to real-world scenarios. Here we explore embryology teaching resources and methodologies and review existing evidence-based studies on their implementation and impact on student learning. In doing so, we aim to inform and support the practice of embryology educators and the learning of their students.

A fresh perspective on histology and embryology - a lens on aesthetics / Una nueva perspectiva sobre histología y embriología: una mirada a la estética

SUMMARY: Histology and embryology is a science that studies the micro structure and function of the body and embryogenesis, and has insight into the microcosmic world of human body. It is delicate and ingeniousness, which greatly satisfy our thirst for knowledge and visual appreciation. This paper expounds the beauty of Science in histology and Embryology from the perspectives of aesthetics on cell morphology, tissue mode, organogenesis and life birth. Aesthetic education in histology and embryology can possible cultivate medical students' humanistic quality and aesthetic thinking, So that they are able to have an access to the essence of life.

RESUMEN: La histología y la embriología son ciencias que estudian la microestructura y la función del cuerpo y la embriogénesis, y tienen una visión del mundo microcósmico del cuerpo humano. Es delicadeza e ingenio, lo que satisface en gran medida nuestra deseo de conocimiento y apreciación visual. Este artículo expone la belleza de la ciencia en histología y embriología desde las perspectivas de la estética sobre la morfología celular, el modo tisular, la organogénesis y el nacimiento de la vida. La educación estética en histología y embriología puede posiblemente cultivar la calidad humanística y el pensamiento estético de los estudiantes de medicina, para que logren tener acceso a la esencia de la vida.

Embrioteca humana: orientaciones metodológicas para su uso en el proceso enseñanza aprendizaje, en formato electrónico / Human embryo library: methodological guidelines for its use in the teaching-learning process, in electronic format

RESUMEN Fundamento: las series histoembriológicas coleccionadas en las embriotecas devienen en importante medio visual en el proceso de enseñanza aprendizaje de la Embriología por el alto potencial didáctico de sus imágenes. Su uso docente requiere orientaciones metodológicas para adecuarse de manera racional y eficiente a los diferentes contextos, niveles y formas organizativas. Objetivo: elaborar orientaciones metodológicas para el uso docente de una embrioteca humana. Métodos: se recurrió a la sistematización de experiencias teóricas y prácticas. Según etapas se definieron muestras, contextos, instrumentos, técnicas, categorías, subcategorías, regularidades, aportes y lecciones aprendidas. Se emplearon métodos y técnicas cualitativas: entrevista semiestructurada, observación, grupos focales, registro de sistematización, técnica de triangulación de fuentes documentales y metodológicas, valoración por especialistas; además del método matemático-estadísticos. Resultados: se confirmó la pertinencia de la embrioteca humana como medio de enseñanza, para lo cual se requieren orientaciones metodológicas; estas fueron elaboradas con enfoque general y específico para contenidos de Embriología en el plan de estudio de la carrera y programa de la especialidad. Se acompañan de 114 imágenes originales a través de las cuales los autores sugieren cómo trabajar didácticamente con este medio. Conclusiones: la sistematización teórica y práctica de la experiencia acumulada en el uso docente de la embrioteca humana permitió elaborar un manual electrónico donde se orienta el trabajo metodológico en los diferentes contextos, niveles y formas organizativas docentes de la Embriología como materia de estudio. Según los especialistas cumple los criterios de rigor: credibilidad, transferencia, dependencia y confirmabilidad.

ABSTRACT Background: the histo-embryological series collected in the embryo libraries become an important visual aid in the teaching-learning process of Embryology due to the high didactic potential of their images. Its teaching use requires methodological orientations to adapt rationally and efficiently to the different contexts, levels and organizational forms. Objective: to develop methodological guidelines for the educational use of a human embryo library. Methods: the systematization of theoretical and practical experiences was used. Samples, contexts, instruments, techniques, categories, subcategories, regularities, contributions and lessons learned were defined according to stages. Qualitative methods and techniques were used: semi-structured interview, observation, focal groups, systematization record, and comparison of sources technique of documentary and methodological sources, evaluation by specialists; in addition to the mathematical-statistical method. Results: the relevance of the human embryo library as a teaching aid was confirmed, for which methodological guidelines are required; these were elaborated with a general and specific focus for Embryology contents in the study plan of the degree and program of the specialty. They are accompanied by 114 original images through which the authors suggest how to work didactically with this aid. Conclusions: the theoretical and practical systematization of the accumulated experience in the educational use of the human embryo library allowed the elaboration of an electronic manual where the methodological work is oriented in the different contexts, levels and educational organizational forms of Embryology as a subject of study. According to specialists, it meets the rigorous criteria: credibility, transfer, dependency and confirmability.