The nose is primarily composed of bone and cartilage, all lined by a mucous membrane. This complex structure provides support, shape, and functionality for breathing and smelling.
Components of the Nose
The nose can be broadly divided into two parts: the external nose and the internal nasal cavity. Both contribute to the overall composition and function of the organ.
External Nose Composition:
The external nose, the visible part, has the following composition:
- Bones: Nasal bones form the bridge of the nose, providing bony support to the upper part.
- Cartilages: The lower part is supported by various cartilages, including:
- Lateral cartilages: These form the sides of the nose.
- Alar cartilages: These shape the tip and nostrils (nares).
- Septal cartilage: Contributes to the nasal septum, separating the nostrils.
- Skin: Covers the external structure.
- Fibrofatty tissue: Found beneath the skin.
Internal Nasal Cavity Composition:
The nasal cavity, located inside the nose, has the following main components:
- Nasal Septum: A wall made of bone (perpendicular plate of the ethmoid bone and vomer) and cartilage that divides the nasal cavity into two passages.
- Mucous Membrane: This membrane lines the entire nasal cavity and contains:
- Epithelium: A layer of cells, including ciliated cells and goblet cells. Ciliated cells sweep mucus towards the pharynx, and goblet cells produce mucus to trap particles.
- Blood vessels: A rich blood supply warms and humidifies the air.
- Conchae (Turbinates): These are bony shelves that project into the nasal cavity. They increase the surface area for warming, humidifying, and filtering air. The superior, middle, and inferior conchae exist.
- Olfactory Epithelium: Located in the upper part of the nasal cavity, this specialized tissue contains olfactory receptor neurons responsible for the sense of smell.
Summary Table:
| Component | Location | Function |
|---|---|---|
| Nasal Bones | Upper part of the external nose | Support the bridge of the nose |
| Nasal Cartilages | Lower part of the external nose | Shape and support the tip and nostrils |
| Nasal Septum | Internal nasal cavity | Divides the nasal cavity |
| Mucous Membrane | Lines the entire nasal cavity | Traps particles, warms and humidifies air |
| Conchae (Turbinates) | Internal nasal cavity | Increases surface area for warming, humidifying, and filtering air |
| Olfactory Epithelium | Upper part of the internal nasal cavity | Sense of smell |
In conclusion, the nose is a complex structure composed of bone, cartilage, mucous membrane, and skin, working together to facilitate breathing and olfaction.
