Animal anatomy is a broad scientific discipline which includes a wide variety of aspects, such as histological anatomy on tissues, functional anatomy to model movements, or radiological anatomy based on brain MRIs. What’s more, all of these aspects need to be multiplied by millions of different species! The multiple facets of veterinary anatomy mean that anatomy atlases have to concentrate on some specific species with a certain specific type of anatomy, and for a defined audience. In this article, we describe how we built a macroscopic anatomical module dealing with dog myology through 2D illustrations, aimed at veterinary students.
Animal anatomy: a painstaking learning process
Myology is the study of the muscular system and muscle function while osteology is the scientific study of bones. These two branches are closely related because muscles are mainly attached to bone structures and allow the movement of bones around joints. This is the reason why we often refer to the “musculoskeletal” system. Osteology and myology are demanding subjects that require great accuracy in order to identify and describe the differences that separate the different species, species bearing in mind the many complex and sometimes subtle variations that exist between them. Furthermore, in animal anatomy, comparative anatomy is the study of the similarities and differences in the anatomy of different species to show the evolutionary relationships among various biological species. It facilitates learning and better understand living organisms: given such complexity, simplicity and clarity of an illustration represents a very useful tool.
Thus, illustrated anatomy involves, rather than illustrations, the transferring of knowledge and understanding.
At the moment, IMAIOS is finalizing a module covering dog myology, which will supplement all the existing modules of our vertebrate animal anatomy atlas.
What work methods are being used to design and build this new animal anatomy module?
Gauthier Kervyn, illustrator and anatomist, provides a detailed explanation: “first, there is a lot of documentation work to be done with regard to what already exists, and which will form a basis for everything to follow. Actually, we cross-check multiples sources of data to guarantee the highest possible reliability’1. The main strength of vet-Anatomy is that it is based on scanned medical animal images. We start from a DICOM file (provided by AzurVet - Delphine Rault), from which we extract a 3D file, which can be then positioned, lit up and used as a template for 2D illustrations. “This process is really innovative and ensures a complete osteological accuracy”. Then, the muscles are extracted from this 3D model based on a true living animal.
What animals have you taken as reference for the CT scan?
The CT scans have been carried out under general anesthesia on living dogs free from any musculoskeletal diseases. Most of the time, the scans were actually carried out for some other medical reason in order not to irradiate the animals without a legitimate reason. We then asked the animals’ owners for their agreement to use the images as anatomical references.
From these 3D references, scientific illustrator cross-check anatomical patterns and dissection images in order to design an original 2D illustration, in order to give a clear and anatomically accurate image of a limb parts or specific muscles.
Another innovative point : the color mode which facilitates the identification of muscles across different anatomical views and representation methods (exterior view, cross-sectional and muscular insertion on the bones), along with providing an opening for functional anatomy. Colors are selected so as to inform on muscle action, with respect to the 3 anatomical reference axes:
- antero-posterior (green) for abduction, adduction movements
- medio-lateral (red) for flexion, extension movements
- vertical (blue) for axial rotation
This module includes isolated muscle, cross-sectional muscle, and progressive dissection illustrations to reflect the relationship between the different muscles and muscular insertions (where the muscle is attached on the bone).
This module is highly comprehensive (over 600 illustrations!) providing 3 or 4 views on average (lateral, medial, cranial and caudal+lateral, dorsal and ventral).
The anatomical images of dog myology are then organized in a local manner with a pedagogical approach, in order to make it a digital support of reference veterinary students.
The advantage of this digital approach is that it is possible to use a lot more images than in a printed book, and thus be able to cover muscles and their insertions separately with different views. It would not be possible to achieve this in a printed atlas for practical and financial reasons (printing costs, volume issues).
In the short and medium term, the aim of our animal anatomy atlas is to provide a comprehensive tool for macroscopic anatomy and the radiological anatomy of pets (dogs, cats, horses, bovines).
The other good news is that a bovine osteology module is currently designed. However, after reading this article, you know that is very long and complex process; you will have to be patient!
In the meanwhile, you can look through the illustrated anatomy modules:
Dog general anatomy
Bull and cow general anatomy
Dog osteology
Dog arthrology
1 Robert Barone 'Anatomie comparée des mammifères domestiques' (sous-titre du volume 1 : 'ostéologie', sous-titre du volume 2 : 'arthrologie et myologie') et Miller's Anatomy of the dog
‘Anatomy of the dog’ de Klaus-Dieter Budras-Patrick H. McCarthy-Wolfgang Fricke-et Renate Richter
