The nasal bone is a small, paired bone located in the upper part of the face, forming the bridge of the nose. Along with the frontal bone, the nasal bones form the base of the nasal pyramid, which gives shape to the nose and separates the nasal cavity into two nasal passages.
The nasal bones are thin and elongated, and they are among the first bones to ossify (harden) during fetal development. Despite their small size, the nasal bones play an important role in the anatomy and function of the nose.
Structure
The nasal bone is a flat, rectangular bone that measures about 2.5 cm in length and 0.5 cm in width. It is thin and slightly curved, with a thicker, more rounded upper end and a thin, pointed lower end. The nasal bone is covered by a thin layer of periosteum, a membrane that surrounds the bone and provides a site for the attachment of muscles, tendons, and ligaments.
It has several prominent landmarks and features. The upper end of the bone is known as the nasal crest, which forms the highest point of the nasal bridge. The lower end of the bone is called the nasal spine, which projects downward and serves as a point of attachment for various structures in the nose. The lateral (side) surface of the nasal bone is smooth and concave, while the medial (inner) surface is rough and convex, with several small foramina (openings) for the passage of blood vessels and nerves.
Location
The nasal bones are located in the midline of the face, just above the nostrils. They are situated between the frontal bone (forehead) and the maxilla (upper jawbone), and they are connected to these bones by small joints called suture lines. The nasal bones also articulate (join) with the ethmoid bone, a small, spongy bone located between the nasal bones and the eye sockets.
The nasal bones can be easily palpated (felt) by running a finger along the bridge of the nose. They are also visible on the surface of the face, forming the top and sides of the nasal pyramid.
Function
The main function of the nasal bone is to provide structural support to the nose. Along with the other bones of the nasal pyramid, the nasal bones help to shape the nose and give it its distinctive appearance. The nasal bones also help to protect the delicate structures inside the nose, such as the nasal mucosa (lining) and the olfactory (sense of smell) receptors.
In addition to its structural function, it also plays a role in the respiratory system. The nasal passages are lined with a thin layer of mucous membrane, which helps to humidify and warm the air we breathe. The nasal bones help to form the walls of the nasal passages, providing a surface for the attachment of the nasal mucosa and other structures that are involved in the respiratory process.
Clinical Significance
The nasal bone is prone to trauma and injury due to its exposed location on the face. Fractures of the nasal bone are common, and they can result from blunt force trauma, such as a blow to the nose, or from more severe injuries, such as car accidents or falls. Nasal bone fractures can cause swelling, bruising, and deformity of the nose, as well as pain and difficulty breathing.
In most cases, nasal bone fractures can be treated with simple measures, such as ice packs and pain medication. More severe fractures may require surgery to realign the bones and restore the normal shape of the nose. The most common surgical procedure for nasal bone fractures is a closed reduction, in which the bones are realigned without making an incision in the skin. In more severe cases, an open reduction may be necessary, in which an incision is made in the skin to access and realign the bones.
In addition to fractures, the nasal bone can also be affected by other conditions, such as sinusitis, a inflammation of the sinuses, or rhinitis, an inflammation of the nasal mucosa. These conditions can cause swelling and congestion of the nasal passages, leading to difficulty breathing and impaired sense of smell. Treatment for these conditions may involve medications, such as decongestants or antihistamines, or more invasive procedures, such as sinus surgery.
