This chapter offers a selective account of the functional anatomy of the adult head, neck and airway as it applies to anaesthetic clinical practice. The anatomy of both inside and outside of the nose has anaesthetic relevance. The epiglottis has evolved to shield the glottis not from anaesthetists, but from nutrients headed towards the stomach. As the trachea must run posteriorly from the glottis to reach the carina in the mediastinum, it is most superficial at its start. As the bronchial tree ramifies beyond the trachea, its initial divisions are crucially asymmetric. The position of the vein and other vessels, and indeed the trachea, can usefully be identified by ultrasound before cricothyroidotomy or tracheostomy. Mouth opening ability depends on craniocervical flexion/extension. The normal cervical spine is largely relevant only to the extent that it obstructs anaesthetists' access to the airway.