Internal organs anatomy

Topographic approach to the study of organs

While normal (systematic) anatomy examines body systems in isolation, topographic anatomy (anatomia topographica) investigates them in a complex. This branch is inextricably linked with operative surgery and addresses a number of strictly applied tasks:

• Description of the layer-by-layer structure of body regions (stratigrafia).
• Determination of the projections of internal organs, nerve trunks, and vessels onto the skin and skeleton (holotopia, skeletotopia).
• Assessment of the mutual arrangement of structures (syntopia).
• Accounting for individual variability (the influence of sex, age, and somatotype on the shape and position of organs).

Such a comprehensive view allows surgeons to correctly plan surgical approaches and techniques based on real anatomical relationships.

The principle of organismal integrity

Studying the body by individual systems is a forced analytical method that must not lead to a mechanistic perception of a human being as a mere sum of parts. In reality, any organ represents an organic unity of diverse tissues, and the organism requires a dialectical approach and synthesis of data.

This is precisely why the dominant rule in medicine is: treat the patient, not the disease. A local lesion of a single internal organ inevitably entails a disorder of the entire organism, acting as a manifestation of a disturbance in overall balance and coordination of processes.

Bone and joint as complex organs

A striking example of organic unity is living bone. Previously, it was believed that bone substance was merely a mechanical casing for the bone marrow. In reality, this is a complex structure where all elements are topographically, structurally, and functionally connected.

• Active muscular work (for example, during physical exercise) enhances the blood supply to bone tissue.
• This improves the nutrition of the red bone marrow, stimulating its hemopoietic and immune functions.
• In turn, the full-fledged functioning of the bone marrow ensures the formation of a robust bone structure.

Similarly, a joint cannot function without the participation of muscles setting the bone levers in motion, vessels and nerves ensuring neurohumoral regulation, and the skin covering it.

Anatomy of a long tubular bone

A tubular bone performs supporting, protective, locomotor, and hemopoietic functions, and also serves as a mineral depot. Its macroscopic structure distinguishes:

1. Diaphysis (diaphysis) — the central part (shaft).
2. Epiphyses (epiphysis proximalis and distalis) — the thickened articular ends.
3. Metaphysis (metaphysis) — the boundary zone between the shaft and the end of the bone (growth zone in children).
4. Apophyses (apophysis) — bone protrusions for the attachment of the ligamentous apparatus and muscles.

On a frontal section of the bone, one can see dense compact bone (substantia compacta), consisting of osteons and forming the periphery of the bone, and spongy bone (substantia spongiosa) with a system of bone trabeculae. Inside the diaphysis lies the medullary cavity (cavitas medullaris), filled in adults with yellow bone marrow, whereas the cells of the spongy bone contain red marrow. Nutrition of the organ is carried out through a special nutrient foramen — foramen nutricium.

Historical context of anatomical development

The accumulation of knowledge about internal organs occurred in isolation across different continents. In Ancient Egypt, organs were removed during mummification out of a belief that the soul was preserved in them, and the earliest medical papyri already described the work of the heart and the movement of blood.

In China, anatomy developed through the prism of acupuncture and the concept of converging systems of nerves, allowing influence over internal organs via distant points. In India, the treatise "Ayurveda" and the practice of yoga provided a powerful impetus to the study of muscles and body types. In Europe, a true breakthrough in anatomical science occurred only during the Renaissance.

Class and exam questions

What else to study on this topic

• Rationale for surgical approaches based on topography
• Individual variability in organ position (age, sex, somatotype)
• Structure of the liver as a complex organ (hepatocytes, biliary tracts)
• The role of N.I. Pirogov in the development of topographic anatomy
• The influence of acupuncture and converging systems on internal organs

Other topics in the "Additional Topics" section

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.