Human Anatomy - H. I. Koliadenko 2009

Sense Organs (Analyzers)
Olfactory Organ

The Olfactory organ occupies a small area of the mucous membrane in the middle part of the superior nasal concha and the posterosuperior part of the nasal septum. The total area of the olfactory region in an adult human is approximately 2.5 sq. cm. The epithelium of the olfactory region consists of Two Types of Cells: supporting cells and olfactory receptor cells.

Olfactory cells are specialized nerve elements; they are spindle-shaped and interspersed among the supporting cells. On the surface of the mucous membrane, olfactory cells form small projections covered with sensory hairs, which serve as the receptor apparatus of the organ. Nerve fibers extend from the olfactory cells toward the foramina of the cribriform plate of the Ethmoid bone, penetrate through its openings, and terminate in synapses near the mitral Cells of the olfactory bulb. Axons emerge from the mitral cells to form the olfactory tract, proceed toward the olfactory trigone, pass through the anterior perforated substance, and follow a complex pathway—still not fully understood—to reach the center of the olfactory analyzer in the Cerebral Cortex, which is localized in the uncus and the hippocampus gyrus.

Class="center">

Fig. 183. Diagram of the olfactory pathway:

1 — olfactory cells of the nasal mucosa; 2 — cribriform plate; 3 — olfactory bulb; 4 — synapse between the axons of olfactory cells and dendrites of mitral cells; 5 — mitral cells; 6 — axons of mitral cells

The olfactory Organs are developed to varying degrees across different mammal groups. Animals are classified as macrosmatic when their olfactory organs have a complex Structure and their cortical center occupies a significant area. This group includes carnivores, ruminants, ungulates, rodents, marsupials, and insectivores. The olfactory organ is less developed in microsmatic species, which primarily include humans, primates, and pinnipeds. In anosmic animals, the nasal conchae and olfactory organ are atrophied, with the dolphin being a typical representative of this group.



Last update: 08/08/2026

Editorial and Educational Adaptation: This material has been compiled based on the primary/original source text. The project team performed an editorial review, corrected technical inaccuracies, structured sections, and adapted the content for an educational format.

What was processed:

  • elimination of formatting defects (OCR errors, structural breaks, corrupted characters);
  • editorial organization of content;
  • standardization of terminology in accordance with academic sources;
  • verification of factual statements against the original source text.

All mentions of the author, publication year, and origin of the primary text have been preserved in accordance with the source.