RESUMO
Muscle fibres are multinuclear cells, and the cytoplasmic territory where a single myonucleus controls transcriptional activity is called the myonuclear domain (MND). MND size shows flexibility during muscle hypertrophy. The MND ceiling hypothesis states that hypertrophy results in the expansion of MND size to an upper limit or MND ceiling, beyond which additional myonuclei via activation of satellite cells are required to support further growth. However, the debate about the MND ceiling hypothesis is far from settled, and various studies show conflicting results about the existence or otherwise of MND ceiling in hypertrophy. The aim of this review is to summarise the literature about the MND ceiling in various settings of hypertrophy and discuss the possible factors contributing to a discrepancy in the literature. We conclude by describing the physiological and clinical significance of the MND ceiling limit in the muscle adaptation process in various physiological and pathological conditions.
Assuntos
Humanos , Fibras Musculares Esqueléticas/fisiologia , Hipertrofia/patologia , Músculo EsqueléticoRESUMO
The last two decades of medical education have been marked by a persistent push towards curricular reform. Anatomy as a discipline, the unshakable foundation of medical teaching for hundreds of years, has been at the centre of this development. Although it is widely agreed that for doctors to be competent, they need an adequate knowledge of anatomy underpinning medicine, there is much less agreement over the quantity required, and who should decide and define it. Many clinicians feel medical students are being under-trained in this basic medical science before reaching the clinical stages. Professional accreditation boards advocate the reduction of factual information in undergraduate medical courses. Anatomists complain of a progressive erosion of the time allocated to the subject. Caught in the midst of this controversy is the student of anatomy who is left bewildered and confused about what is required from him to become a safe and competent health professional. The way forward might, first, be for medical schools to facilitate discussions between students, anatomy professors, and clinicians to bring these divergent perspectives into alignment. Second, the anatomists need to re-invent themselves in two principal frameworks: first, to present the subject in the context within which it will be utilised by the student, and second to employ the overwhelming learning tool of today, i.e. technology, in their teaching and assessment of the subject
Assuntos
Currículo , Educação de Graduação em Medicina , Faculdades de Medicina , Estudantes de MedicinaRESUMO
Traditionally, summative practical examination in anatomy takes the form of 'spotters' consisting of a stream of prosections, radiological images and dissections with pins indicating specific structures. Recently, we have started to administer similar examinations online using the quiz facility in Moodle[TM] [a free, open-source web application for producing modular internet-based courses] in addition to the traditional format. This paper reports on an investigation into students' perceptions of each assessment environment. Over a 3-year period, practical assessment in anatomy was conducted either in traditional format or online via learning management software called Moodle[TM]. All students exposed to the two examination formats at the College of Medicine and Health Sciences, Sultan Qaboos University, Oman, were divided into two categories: junior [Year 3] and senior [Year 4]. An evaluation of their perception of both examination formats was conducted using a self-administered questionnaire consisting of restricted and free response items. More than half of all students expressed a clear preference for the online environment and believed it was more exam-friendly. This preference was higher amongst senior students. Compared to females, male students preferred the online environment. Senior students were less likely to study on cadavers when the examination was conducted online. Specimen quality, ability to manage time, and seating arrangements were major advantages identified by students who preferred the online format. Computer-based practical examinations in anatomy appeared to be generally popular with our students. The students adopted a different approach to study when the exam was conducted online as compared to the traditional 'steeplechase' format
Assuntos
Humanos , Masculino , Feminino , Atitude , Avaliação Educacional/métodos , Computadores , Sistemas On-Line , Software , Estudantes de Medicina , Inquéritos e QuestionáriosRESUMO
Available literature on medical education charts an emerging trend in the field of anatomy. In the past decade, assisted by innovations in informatics and the paradigm shift in medical education, the hands-on experience of cadaver dissection has progressively becoming a relic of the past. Within the context of the situation in Gulf Cooperation Council countries, this paper compares the traditional teaching approach with the modern one that tends to emphasise technical gadgetry, virtual reality and plastic models rather than hands-on-experience to impart knowledge and skill. However, cadaver-based learning is an important building block for the future physician and surgeon since clinical astuteness is likely to rely on skills gained from hands-on experience rather than the tendency to learning through virtual reality found in modern curricula