Olfactory cortex

The olfactory cortex is a continuation of the phylogenetically ancient structures of the brain stem. Olfactory impulses from the primary olfactory center to the brain are carried through the olfactory tract and extracranial cranial nerves, some of which, as part of the internal carotid cord, pass into the corpus callosum, forming the temporary olfactory cortex.

The development of the olfactory analyzer occurs late. Sensitive cells of the olfactory region of the peripheral region are already present in the newborn, but continue to develop after birth. In the first month their number increases by 5 times, in the second by 7-8 and by the end of the third month it reaches its maximum. However, they are located unevenly and form a large gap between their cellular clusters. A special feature is the presence of cell groups without olfactory neurons. There are practically no cortical olfactory sections. An important feature of newborns is the gradual formation of the sense of taste, and the long-term persistence of “olfactory blindness,” as indicated by a weak reaction to odorous substances. At this age, the olfactory nerve receives from 420 to 680 impulses per second, and afferent connections of the presumptive neurons of the olfactory receptors with the neurons of the olfactory complex are formed. By the end of the first year of life, when the bone and facial skulls do not yet securely enough fix the brain structures to each other, the nasal cortex in children is poorly developed, its thickness averages 0.5 - 1 mm. It is especially poorly developed at the tip and lateral to it. The caloric curve at this time has 2 small pronounced maxima on both sides during inhalation