where are olfactory receptors located in human body
Olfactory receptor In vertebrates, the olfactory receptors are located in both the cilia and synapses of the olfactory sensory neurons[4] and in the epithelium of the human airway.[5]  In insects, olfactory receptors are located on the antennae and other chemosensory organs.[6] Sperm cells also express odor receptors, which are thought to be involved in chemotaxis to find the egg cell.[7]
Stomach In classical anatomy, the human stomach is divided into four sections, beginning at the gastric cardia,[6] each of which has different cells and functions.
Sensory neuron Similarly to olfactory receptor neurons, taste receptors (gustatory receptors) in taste buds interact with chemicals in food to produce an action potential.
Small intestine Food from the stomach is allowed into the duodenum through the pylorus by a muscle called the pyloric sphincter.