The external part of the nose, known as the external nose, is made up of skin, cartilage, and bone. The nostrils, or nares, are the two openings on the underside of the nose through which air enters and exits. The septum, a thin wall of cartilage, divides the nasal cavity into two passages. The turbinates, which are bony projections covered with mucous membranes, are located inside the nasal passages and help to warm, moisten, and cleanse the air we breathe.
The internal part of the nose, known as the nasal cavity, extends from the nostrils to the back of the throat. The olfactory epithelium, which is responsible for the sense of smell, is located in the roof of the nasal cavity. The paranasal sinuses are four air-filled cavities located around the nasal cavity. They help to produce mucus, lighten the skull, and resonate the voice.
The nose plays several important roles in the human body:
* Olfaction: The nose is the primary organ for the sense of smell. Olfactory receptors in the nasal cavity detect chemical substances in the air and transmit signals to the brain, allowing us to perceive different smells.
* Respiration: The nose is the main passageway for air to enter and exit the respiratory system.
* Filtration: The nose acts as a filter, trapping dust, pollen, and other particles from entering the lungs.
* Humidification: The nasal cavity helps to moisten the air we breathe, which is important for maintaining proper respiratory health.
* Temperature regulation: The nasal passages help to regulate the temperature of the air we breathe, bringing it to a comfortable level before it reaches the lungs.
Overall, the nose is a vital organ that serves multiple important functions in the human body. It allows us to smell, breathe, and maintain respiratory health, and its unique shape and structure contribute to our facial appearance and expressions.