ISSA Nutritionist Practice Exam 2026 - Complete Preparation Guide

The olfactory system is the organ system primarily responsible for the sense of smell in humans. It consists of specialized sensory neurons located in the nasal cavity that detect odor molecules in the air. When these neurons are stimulated by specific chemicals, they send signals to the brain where the perception of smell is processed. This system plays a crucial role not only in detecting scents but also in influencing taste and triggering memories and emotions associated with particular smells.

The other systems mentioned contribute to different functions: the digestive system is involved in processing food, the nervous system facilitates communication and control within the body, and the respiratory system is responsible for the intake of oxygen and expulsion of carbon dioxide. While the nervous system and respiratory system may have overlapping interactions with the olfactory system, they do not specifically designate the capability for smell.