Which of the following bones do not contribute to the nasal septum

Question 1

Which of the following bones do not contribute to the nasal septum

a.       Sphenoid

b.      Lacrimal

c.       Palatine bone

d.      Ethmoid

Answer :

B : Lacrimal

Reference :

Gray’s Anatomy 38^th Edition Page 574 :

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Discussion:

The medial wall or nasal septum, between the roof and floor, is a thin sheet of bone with a wide anterior deficiency occupied by septal cartilage; its bony part is largely vomer and perpendicular plate of the ethmoid. The vomer extends from the sphenoidal body to the bony palate, forming the posteroinferior region, including the posterior border; it is furrowed by vessels and nerves. The perpendicular plate of the ethmoid forms the septum's anterosuperior part, continuous above with cribriform plate.

At the upper and lower limits of the medial wall other  bones make minor contributions to the septum: anterosuperior are the nasal bones and frontal's nasal spine, posterosuperior are the sphenoid's rostrum and crest, and inferiorly, the maxillary and palatine nasal crests. The vomer is grooved by the nasopalatine nerves and vessels.

Explanation

Self Explanatory

Comments

The cartilage of the septum (or septal cartilage, or quadrangular cartilage) is somewhat quadrilateral in form, thicker at its margins than at its center, and completes the separation between the nasal cavities in front.

Its anterior margin, thickest above, is connected with the nasal bones, and is continuous with the anterior margins of the lateral cartilages; below, it is connected to the medial crura of the greater alar cartilages by fibrous tissue.

Its posterior margin is connected with the perpendicular plate of the ethmoid; its inferior margin with the vomer and the palatine processes of the maxillae.

Tips

The septum is often deviated, most commonly at the vomero-ethmoidal suture.