Basic Sciences - Anatomy of Airway Flashcards
Formal name for ‘pillars of the fauces’ in mouth
Palatoglossal arch (anterior)
Palatopharyngeal arch (posterior)
Functions of nasal passage / nasopharynx
Warm air
Humidify air
Filter inspired air
Olfaction
Speech resonation
Nasal cavity epithelium
Pseudostratified ciliated columnar epithelium
(respiratory mucosa)
Bones which form the hard palate
Palatine process of the maxilla
Horizontal part of the palatine bone
Afferent nerve for gag reflex
Glossopharyngeal nerve
Efferent nerve for gag reflex
Vagus nerve
Components of the pharynx
Nasopharynx
Oropharynx
Laryngopharynx
Lateral recesses either side of larynx
Piriform fossae
Adenoids definition
Collection of lymphoid tissue on roof and posterior wall of pharynx
Adenoids age group
Develop in early childhood
Regress at puberty
Sensory supply to the tonsils
Branches of:
- Glossopharyngeal
- Maxillary
- Mandibular
Tonsillar anaesthesia technique
Infiltration of analgesia into tonsillar bed is more effective than nerve blockade
Swallowing reflexes to prevent aspiration
- Closure of the laryngeal sphincter
- Upward movement of the larynx behind the base of the tongue
- Reflex inhibition of breathing and channelling of liquid or food laterally by the epiglottis into the piriform fossae
- Epiglottis may also act as a ‘lid’ to the larynx to prevent substances entering the trachea
Articulating cartilages forming larynx
Thyroid
Cricoid
Epiglottis
Paired cartilages forming larynx
Arytenoid
Corniculate
Cuneiform
Formal name for false vocal cords
Vestibular folds
Superior to true vocal cords
Formal name for true vocal cords
Vocal folds
Inferior to false vocal cords
Gap between vocal cords
Rima glottidis (aka ‘the glottis’)
Narrowest part of the airway
Space above epiglottis where tip of laryngoscope is placed
Vallecula
Name of posterior ‘nodules’ visible at posterior aspect of larynx
Arytenoid complex
Muscle groups of the larynx
Extrinsic
Intrinsic
Functions of extrinsic muscles of the larynx
Work with other muscles attached to the hyoid to move the larynx up and down during swallowing
Functions of intrinsic muscles of larynx
Move vocal cords
Diagram of intrinsic muscles of larynx
Function of posterior cricoarytenoids muscles
Abduct vocal cords on inspiration
Pulls posterior ends of arytenoid cartilages together medially to achieve abduction
Function of lateral cricoarytenoids muscles
Adduct vocal cords to close them
Function of aryepiglottics and thyroepilottics muscles
Laryngeal sphincters
Close the laryngeal inlet during swallowing
Function of cricothyroid muscles
Tensors of the cords
Act by tilting the cricoid cartilage on the thyroid cartilage
Function of the thyroarytenoids muscles and vocalis muscles
Relax the vocal cords
Vocalis muscle responsible for fine adjustment of the cords
Nerve supply to the larynx
Sensory supply to larynx
Superior laryngeal nerve - internal laryngeal nerve branch superior to vocal cords
Recurrent laryngeal nerve inferior to vocal cords
Motor supply to larynx
Superior laryngeal nerve - external laryngeal branch supply to cricothyroid muscle
Recurrent laryngeal nerve to all intrinsic muscles of larynx except cricothyroid muscle
Path of right recurrent laryngeal nerve
Passes under right subclavian artery to ascend to larynx
Path of the left recurrent laryngeal nerve
Passes under the aortic arch to ascend to the larynx
Symptoms of damage to superior laryngeal nerve damage
Temporary hoarse voice due to loss of cricothyroid muscle function - muscle on other side compensates
Increased aspiration risk due to loss of sensation above cords
Symptoms of Unilateral recurrent laryngeal nerve damage
Hoarse voice with potential partial compensation from other side
Glottis cannot close tightly so cannot generate positive intrathoracic pressure to cough effectively
Aspiration risk - loss of infraglottic sensation
Symptoms of Bilateral recurrent laryngeal nerve damage
Bilateral vocal cord palsy
Severe respiratory distress
Stridor as flaccid vocal cords flap together
Management of Bilateral recurrent laryngeal nerve palsy
Urgent intubation acutely
Tracheostomy likely to follow
Why cricothyroidotomy should only be used as temporary airway
Vocal cords in close proximity and may be damaged
Risk of subglottic stenosis
Approximate vertebral level of larynx
C4-C6
Cricoid cartilage ~ C6
