**Core Concept**
The nasal septum is a thin wall of cartilage and bone that separates the nasal passages and is formed by the perpendicular plate of the ethmoid bone, the vomer, and the septal cartilage. The nasal septum provides structural support to the nasal passages and helps to filter, warm, and humidify the air we breathe.

**Why the Correct Answer is Right**
The nasal septum is primarily composed of the perpendicular plate of the ethmoid bone, the vomer, and the septal cartilage. The perpendicular plate of the ethmoid bone is a thin, flat plate of bone that forms the majority of the nasal septum. The vomer is a single, thin, curved bone that forms the posterior part of the nasal septum. In contrast, the following bones do not contribute to the nasal septum: the maxilla, the lacrimal bone, the palatine bone, and the inferior nasal conchae.

**Why Each Wrong Option is Incorrect**
* **Option A:** The maxilla does not contribute to the nasal septum, as it forms the sides of the nasal cavity and the floor of the nasal passages.
* **Option B:** The lacrimal bone does not contribute to the nasal septum, as it forms the medial wall of the orbit and the lacrimal fossa.
* **Option C:** The palatine bone does not contribute to the nasal septum, as it forms the posterior part of the hard palate and the floor of the nasal passages.
* **Option D:** The inferior nasal conchae do not contribute to the nasal septum, as they are thin, curved bones that form the lateral walls of the nasal passages.

**Clinical Pearl / High-Yield Fact**
The nasal septum is a common site for deviated septum, a condition where the septum is displaced from its normal position, which can cause nasal obstruction, congestion, and difficulty breathing.

**Correct Answer:** A. The maxilla does not contribute to the nasal septum.