This document provides an overview of the anatomy and physiology of the nose and paranasal sinuses. It describes the external and internal structures of the nose, including bones, cartilages, walls and openings. It details the anatomy and drainage pathways of the paranasal sinuses. It explains the blood supply, nerve innervation and lymphatic drainage of the nose. It discusses the functions of the nose in respiration, air conditioning, protection of the lower airways and olfaction. It provides details on the physiology of smell and tests used to evaluate olfactory function.