Anatomophysiological relationships and clinical considerations of taste and smell loss in patients with COVID-19

Figure 1 Flow diagram showing the selection of articles in the PubMed/MEDLINE, Web of Science, and Scopus databases. COVID-19: The new coronavirus 2019.

Figure 2 Olfactory pathway and its components. A: Fillets of the olfactory nerves, the first pair of cranial nerves, inside the nasal cavity in the upper third of the nasal septum; B: Olfactory bulb; C: Olfactory tract; D: Cribriform plate of the ethmoid bone, which communicates the nasal cavity with the anterior cranial fossa.

Figure 3 Endocranial view of the 12 pairs of cranial nerves in a natural anatomical piece. I: Olfactory nerve; II: Optic nerve; III: Oculomotor nerve; IV: Trochlear nerve; V: Trigeminal nerve; VI: Abducens nerve; VII: Facial and intermediate nerve; VIII: Vestibulocochlear nerve; IX: Glossopharyngeal nerve; X: Vagus nerve; XI: Accessory nerve; XII: Hypoglossal nerve. Red arrow indicates the cribriform plate of the ethmoid bone; blue arrow indicates the olfactory bulb; purple arrow indicates the olfactory tract; yellow arrow indicates the beginning of the spinal cord at the level of the foramen magnum; green arrow indicates the sigmoid sinus; white star indicates the cranial dura mater.

Figure 4 Natural anatomical piece in midsagittal section (medial view). Yellow arrow represents the chorda tympani nerve, a branch of the intermediate nerve; green arrow represents the lingual nerve, a branch of the mandibular division of the trigeminal nerve.

Figure 5 Dorsal region of the tongue. A-C: Yellow line indicates the terminal sulcus, which separates the tongue into body or two anterior thirds and root or posterior third; D: Green arrow indicates the epiglottis cartilage of the larynx, where taste is made by the vagus nerve.