anatomical structure nasal septum http://upload.wikimedia.org/wikipedia/commons/6/65/Gray854.png FMA:54375 We follow AAO in making this part of the nasal skeleton VHOG:0000017 EMAPA:17608 septal cartilage A median dividing wall, sagittally directed, which divides the nasal cavity into the right and the left nasal fossae. [Dorian_AF, Elsevier's_encyclopaedic_dictionary_of_medicine, Part_B:_Anatomy_(1988)_Amsterdam_etc.:_Elsevier][VHOG] EHDAA2:0001234 OpenCyc:Mx4rv7e-k5wpEbGdrcN5Y29ycA EHDAA2:0004104 Medial vertical wall between nasal capsules.[AAO] uberon Whatever the common ancestor of the lamprey and gnathostomes may have looked like, it most likely possessed a neural-crest-derived premandibular ectomesenchyme closely associated with the NHP. Invention of the jaw subsequently required a space for the nasal septum and maxillary process to develop, which might have been provided by subdivision of the NHP into the nasal placode and the hypophysis (diplorhiny, the state of bilaterally separated nasal openings, would also have been a prerequisite for this).[well established][VHOG] The nasal septum separates the left and right airways in the nose, dividing the two nostrils. It is depressed by the Depressor septi nasi muscle. [WP,unvetted]. NCIT:C33160 septum of the nose septum nasi AAO:0000559 AAO:0010135 Medial, vertical plate that separates the nasal capsules.[AAO] UBERON:0001706 UMLS:C0027432 MESH:A02.165.639 septum mobile nasi EHDAA:6809 GAID:115 MA:0000285 neural crest-derived structure