Anaes · Applied anatomy

Airway and larynx anatomy

Also known as Airway anatomy · Larynx anatomy · Laryngeal cartilages · Recurrent laryngeal nerve · Superior laryngeal nerve · Cricothyroid membrane

The airway is the anaesthetist's primary organ, and its anatomy underpins every act of intubation, laryngeal-mask placement, front-of-neck rescue and nerve block. The framework rests on six exam-critical ideas. First, the airway runs from the nose and mouth through the pharynx (nasopharynx, oropharynx, laryngopharynx) to the larynx and then the trachea, with the larynx sitting opposite the third to sixth cervical vertebrae. Second, the laryngeal skeleton is built from three single cartilages (thyroid, cricoid and epiglottis) and three paired cartilages (arytenoid, corniculate and cuneiform); the cricoid is the only complete ring of cartilage in the airway and is the key landmark for both the Sellick manoeuvre and a surgical airway. Third, the cricothyroid membrane stretches between the thyroid cartilage above and the cricoid below and is the target for emergency front-of-neck access (cricothyroidotomy). Fourth, the larynx is innervated by two branches of the vagus: the superior laryngeal nerve (whose internal branch is sensory to the larynx above the cords and whose external branch motor-innervates the cricothyroid, the tensor of the cords) and the recurrent laryngeal nerve (which is motor to all the other intrinsic muscles and sensory below the cords); damage to the recurrent laryngeal nerve paralyses a vocal cord in the paramedian position and causes hoarseness. Fifth, the trachea bifurcates at the carina into a right main bronchus that is wider, shorter and more vertical (the site of inadvertent right main-stem intubation and of aspiration) and a longer, narrower left main bronchus. Sixth, the paediatric airway differs structurally from the adult's — a relatively larger tongue and occiput, a higher, more anterior larynx (C3-C4 in the infant versus C6 in the adult), a large U-shaped epiglottis, and the narrowest point at the cricoid (not the vocal cords as in the adult) — which is why uncuffed tubes were traditionally used in young children and why the paediatric airway is more easily obstructed. Built on the larynx and cervical-trachea anatomy review (McCullagh 2022), the Difficult Airway Society 2015 guidelines (Frerk 2015), the CT cricothyroid-membrane-height study (Nutbeam 2017), the cricothyroid emergency-access review (Bribriesco 2018), the ultrasound front-of-neck-access review (Rai 2020), the recurrent-laryngeal-nerve paralysis review (Myssiorek 2004), the external-superior-laryngeal-nerve meta-analysis (Cheruiyot 2018), the intraoperative neural-monitoring guideline (Randolph 2011), the paediatric tracheobronchial-anatomy study (Tahir 2009), the paediatric airway-development review (Di Cicco 2021), the cuffed-versus-uncuffed-tube trial (Khine 1997), the paediatric neuromuscular-block review (Bonfiglio 2026), the IRIS cricoid-pressure trial (Birenbaum 2019), the bedside airway-assessment study (Eltrabily 2026), the endotracheal-tube-positioning study (Kufel 2026), the front-of-neck-access simulation study (Mullally 2026), and the superior-laryngeal-nerve-block case report (Chen 2026).