Concepts of variation and normality in morphology: Important issues at risk of neglect in modern undergraduate medical courses

Abstract

In anatomy, normality embraces a range of morphologies and includes those that are most common and others called variations which are less frequent but not considered abnormal. Variations ranging from subtle to remarkable affect every part of the human body. They may have important influences on predisposition to illness, symptomatology, clinical examination and investigation, and patient management including operative surgery. Recognition of variations enables clinicians to distinguish features which merit further investigation or treatment from those which do not. We believe the concepts of normality and variation should be introduced early in the medical course and that the dissecting laboratory is the ideal venue. Students who are able to examine several specimens or are privileged to dissect soon realize that each cadaver is unique. Knowledge of variations should be reinforced in several components of the medical course where physical examination, imaging investigations, surgical procedures, and autopsies are studied. Appreciation of the range of normality including variations matures as experience is gained over several years. Current trends in undergraduate courses--including reduced exposure to dissection and dissected specimens, increased use of plastic bones, models and computer-generated images, loss of experienced teachers, especially those who are medically qualified, and loss of morphological approach-- all conspire to defer the stage when students encounter variation. We are concerned that these trends will compromise the knowledge and understanding of variation required to start practicing medicine safely and competently.

Integrating gross pathology into teaching of undergraduate medical science students using human cadavers

“…Many studies have suggested that prosections and audiovisuals can produce better learning outcomes in teaching anatomy when compared to cadaver‐based teaching methods . However, these methods have limited value in teaching histopathology because the gross tissue changes and pathogenesis of a disease process will be better understood with greater hands‐on experience . In this study, our findings concurred with the view that the histopathology learning experience can be enhanced by direct physical handling of pathological tissues and undergoing training in dissection.…”

“…The macroscopic tissue changes occur as a result of a pathological condition and the pathogenesis of a disease process is better understood by more hands‐on experience . Furthermore, handling and dissection of tissue specimens provide students with a better appreciation of three dimensional tissue/organ features . In this interventional study, we provided students an opportunity to actively explore the cadaveric materials, identify abnormal tissues, compare the macroscopic characteristics of pathological lesions and corresponding normal tissues as well as subsequently engage in a tissue handling and dissection.…”

Prosection vs. dissection, the debate continues: Rebuttal to Granger

“…It is true that the wide range of anatomically normal structural relationships may be made apparent in the anatomy laboratory. It is also true that few modern textbooks contain figures depicting normal variations, let alone the population frequency of each variation (Willan and Humpherson, 1999). Students working with prosections have the opportunity to view several variations, rather than the single variation that may be present in their dissection cadaver.…”

The role of three-dimensional information in health care and medical education: The implications for anatomy and dissection

“…The market forces that continually impact businesses have recently been illustrated by Grove (1996) in his bestseller Only the Paranoid Survive. One does not have to look far to see these same ruthless pressures in health care (Koop, 1998) and medical education (Cahill and Leonard, 1999;Monkhouse and Farrell, 1999;Voon and Marks, 1999;Willan and Humpherson, 1999). The result is that shareholders and university finances are favored over the health of patients or the education of students.…”