Exploring the inclusion of anatomical variation in medical education

Anatomical variation is the norm: A novel curriculum framework

Anatomical variation is an inherent part of every health curriculum, due in large to the negative clinical consequences that can ensue if anatomical variation is not thoroughly understood. However, current literature fails to describe any structured whole-of-course pedagogy for the teaching of anatomical variation in higher education. This study therefore aimed to (i) propose a whole-of-course curriculum framework to guide academic development and implementation of anatomical variation resources and assessment; and (ii) assess the depth of anatomical variation knowledge in a multiyear undergraduate health-science cohort (n = 152) at the Queensland University of Technology. Current anatomical variation pedagogy, and subsequently the need for the curriculum framework, were explored using a scoping review protocol. As part of this study, anatomical variation was novelly defined as macroscopic differences in morphology (shape and size), topography (location), developmental timing, or frequency (number) of an anatomical structure between individuals that form during embryological or subadult development and result in no substantive, observable interruption to physiological function. The framework incorporated three themes of anatomical variation learning outcomes: description of anatomical variation, theories of the professional implications of variation, and investigation of variant formation. These themes were strongly aligned with the concepts recommended for teaching identified through the scoping review. Significant deficits in anatomical variation student knowledge were identified, with the third-year cohort recording a mean total score of only 54.6%. A strong recommendation to implement the anatomical variation curriculum framework in all medical and health-science curricula is made to intentionally develop student understanding of anatomical variation and improve future clinical practice.

Hidden diversity: comparative functional morphology of humans and other species

Gastrointestinal (GI) morphology plays an important role in nutrition, health, and epidemiology; yet limited data on GI variation have been collected since 1885. Here we demonstrate that students can collect reliable data sets on gut morphology; when they do, they reveal greater morphological variation for some structures in the GI tract than has been documented in the published literature. We discuss trait variability both within and among species, and the implications of that variability for evolution and epidemiology. Our results show that morphological variation in the GI tract is associated with each organ's role in food processing. For example, the length of many structures was found to vary significantly with feeding strategy. Within species, the variability illustrated by the coefficients of variation suggests that selective constraints may vary with function. Within humans, we detected significant Pearson correlations between the volume of the liver and the length of the appendix (t-value = 2.5278, df = 28, p = 0.0174, corr = 0.4311) and colon (t-value = 2.0991, df = 19, p = 0.0494, corr = 0.4339), as well as between the lengths of the small intestine and colon (t-value = 2.1699, df = 17, p = 0.0445, corr = 0.4657), which are arguably the most vital organs in the gut for nutrient absorption. Notably, intraspecific variation in the small intestine can be associated with life history traits. In humans, females demonstrated consistently and significantly longer small intestines than males (t-value₁₅ = 2.245, p = 0.0403). This finding supports the female canalization hypothesis, specifically, increased female investment in the digestion and absorption of lipids.