Question

In detection of smell, odorants

themselves _______.

A. bind to receptors and stimulate opening of
ion channels
B. are neurotransmitters
C. are detected by chemoreceptors in the lungs
D. are or do all of the above

Answer 1

In the detection of smell, odorants bind to specialized receptors on olfactory neurons, initiating a signaling cascade that leads to the generation of an action potential and the perception of odor.

Step-by-step explanation:

In the detection of smell, odorants themselves bind to receptors and stimulate the opening of ion channels. This process is part of sensory transduction, where odorant molecules, which are volatile chemicals, interact with olfactory neurons. These neurons are located within the olfactory epithelium in the superior nasal cavity and contain special receptors that are sensitive to different odorants. Once odorants enter the nose, they dissolve in the epithelium and bind to these receptors. This binding to receptor proteins activates a G protein-coupled receptor, which then produces a graded membrane potential, leading to the generation of an action potential in the neurons. These signals are then sent directly to the olfactory bulb of the brain for processing, ultimately resulting in the perception of smell.