Figure 1. Sagittal section of the nasal cavity showing the nasal vestibule (A), atrium (B), respiratory area: inferior turbinate (C1), middle turbinate (C2) and the superior turbinate (C3), the olfactory region (D) and nasopharynx (E). Reproduced with permission from ref. [20]

From

Nasal Drug Delivery Systems: An Overview

Muhammad U. Ghori, Mohammed H. Mahdi, Alan M. Smith, Barbara R. Conway

American Journal of Pharmacological Sciences. 2015, 3(5), 110-119 doi:10.12691/ajps-3-5-2