Sensing taste and odours
Part 4: Humidity Receptors
Some sensilla respond to humidity (water in the air). These are peg-like with no external pores but often have a rough appearance to the distal shaft. Because they usually respond to changes in temperature as well as humidity, they are not thought of as odour receptors but the mechanism involved in stimulation appears to be similar to the olfactory type.
Examples are the coelocapitular sensilla, a mushroom-shaped protrusion set in a narrow cylindrical pit on the honeybee antennae; the sensillum capitulum on the antennae of the cockroach, Periplaneta americana; the styloconic sensilla on the tips of the antennal branches of the silkmoth, Bombyx mori.
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Diagram of a humidity sensor similar to that seen in the silk moth, Bombxy mori (Steinbrecht, R.A. & Müller, B. (1991). The thermo- /hygrosensitive sensilla of the silkmoth, Bombyx mori: morphological changes after dry- and moist-adaptation. Cell Tissue Research, 266, 441-456. |
Go on to part 5: Distribution of sensilla