Final answer:
The Vomer and Perpendicular Plate of the ethmoid bone form the upper and lower portions of the nasal septum, respectively, dividing the nasal cavity into two halves. These structures, along with the septal cartilage, contribute to the stability and shape of the nose.
Step-by-step explanation:
The Vomer and Perpendicular Plate of the ethmoid bone are structures within the nasal cavity that play a significant role in the formation of the nasal septum. The perpendicular plate of the ethmoid bone is a downward, midline extension that forms the upper portion of the nasal septum. This plate, along with the Vomer bone, which forms the lower and posterior parts of the septum, divides the nasal cavity into two halves. Additionally, the ethmoid bone contributes to the lateral walls of the upper nasal cavity and gives rise to the superior and middle nasal conchae, which are thin, curved projections that extend into the nasal cavity.
Together these bones, along with the septal cartilage, create the flat, midline structure known as the nasal septum. The septal cartilage fills in the gap between the perpendicular plate of the ethmoid bone and the Vomer bone and extends into the nose, separating the right and left nostrils.