The human nose plays a fundamental role in both breathing and the sense of smell. Its intricate structure filters, warms, and humidifies the air we inhale, preparing it for the lungs. The nose also contributes to facial aesthetics, with its shape and size varying among individuals. Understanding its internal components helps appreciate its functions.
The Bones of the Nose
The bony framework of the nose provides its foundational structure, particularly for the upper and middle portions. The bridge of the nose is formed by two small nasal bones, which join at the midline to form the upper one-third of the nose. The overall bony complex defining the nasal cavity involves several other bones.
The broader bony structure of the nasal cavity includes contributions from other facial and cranial bones. The maxillae, or upper jaw bones, contribute to the floor and lateral walls; the frontal bone, in the forehead, forms the superior aspect or root. The ethmoid bone contributes to the roof and upper part of the nasal septum, the wall that divides the nasal passages. The vomer forms the lower and posterior part of the nasal septum. Palatine and lacrimal bones also contribute to the bony frame of the nasal cavity.
Beyond Bone: Cartilage’s Role
While bones provide the rigid upper framework, a significant portion of the nose, particularly its lower and outer parts, consists of cartilage. This flexible tissue complements the bony structure, giving the nose its characteristic shape and resilience. Cartilage provides both form and support.
Several types of cartilage contribute to the nasal structure. The septal cartilage is a flat piece that forms the anterior portion of the nasal septum, separating the two nasal cavities. Lateral nasal cartilages are triangular plates located below the nasal bones, fusing with the septal cartilage to provide support and form part of the external nose’s lateral wall. Major alar cartilages form the lower and anterior framework of the external nose’s lateral wall, defining the shape of the nostrils and the nasal tip. Minor alar cartilages further aid in providing form and strength at the base of the nostrils.
Why Nasal Bones Matter
The bony framework of the nose serves several functions beyond providing shape. It offers structural support for the entire nasal complex, protecting delicate internal components like the nasal septum and turbinates from external forces and impacts.
The bony architecture also shapes the nasal passages for efficient airflow. As air enters the nose, the bony and cartilaginous structures direct its flow, facilitating warming and humidifying before it reaches the lungs. This pre-conditioning of inhaled air helps protect the respiratory system by trapping airborne particles.