Z Zellforsch 96:250–274Īndres KH (1975) Neue morphologische Grundlagen zur Physiologie des Riechens und Schmeckens. Brain 72:186–197Īndres KH (1969) Der olfaktorische Saum der Katze.

Possible sex-dependent differences are only found for these densities and dendritic ending diameters.Īllison AC, Warwick RTT (1949) Quantitative observations on the olfactory system of the rabbit. Dendritic ending densities range from 4.5 × 10 6 (frog) to 8.3 × 10 6 (dog) endings per cm 2. Freeze-fracture diameters are usually larger than those seen by techniques using dehydration. Dimensions of other structures e.g., axons, dendrites and dendritic endings are compared in the various species. The relative magnitudes of the diameters of the cilia and microvilli are, except for frog, the same for all species studied. When corrected for cilia which were not observed, mammalian receptor endings bear 17 cilia on average, whereas frog receptor endings have 6 cilia. Quantitative comparisons are made of the different structures of interest. The freeze-fracture morphology of intracellular secretory vacuoles present in olfactory supporting, Bowman's and respiratory glandular cells of the frog is similar in all these epithelia. Smooth vesicles are also found in the mucus of other types of epithelium (respiratory epithelium and Bowman's glands). Some of these show intramembranous particle distributions similar to those of the rest of the cilia, whereas others are devoid of particles.

Within the mucus overlying the olfactory epithelium membranous vesicles, often attached to olfactory cilia, are seen.

Special attention has been paid to cilia and microvilli present at these surfaces, although the observations include various other structures such as small intracellular vacuoles present in the olfactory receptor endings and infrequent brush cells. A comparative study using freeze-fracturing has been made of surface structures of olfactory and nasal respiratory epithelia of frog, ox, rat and dog.

Download the frog and the ox