L10: Pharynx and larynx Flashcards
Constrictor muscles of pharynx
ALL have inf and ant part missing and have left and right joint at pharyngeal raphe
Superior, middle and inferior constrictor muscles
Superior constrictor attachments
- Superiorly attached to base of skull (sphenoid bone, temporal bone, pharyngeal tubercle)
- Anteriorly attached to pterygomandibular raphe (ant to raphe is buccinator in the same plane as sup constrictor)
Middle constrictor attachments
Attached to lower part of stylohyoid ligament, lesser horn of hyoid bone and greater horn of hyoid bone
Inferior constrictor attachments
- Attached to oblique line on thyroid cartilage (where sternothyroid and thyrohyoid also attach)
- And attached down to cricothyroid muscle and cricoid cartilage
Longitudinal muscles
Names and function
- Salpingopharyngeus (attached to cartilaginous part of stylopharyngeus tube)
- Palatopharyngeus
- Stylopharyngeus
From sites of origin run downwards and attach into pharyngeal wall.
Together with pharyngobasilar fascia (between mucosa and constrictor muscles) stabilises the pharynx
Elevate wall and/or assist in swallowing
Gaps in pharyngeal wall
Oropharyngeal triangle:
(post free edge of mylohyoid, inf edge of sup constrictor, sup edge of mid constrictorz0
- Lingual a after branching off ext carotid goes anteriorly into triangle
- Hypoglossal n [XII], glossopharyngeal n [IX]
- Lingual n
Between mid and inf constrictor:
- Internal laryngeal n (branch of sup laryngeal) and vessels enter
Below inferior constrictor:
- Recurrent laryngeal n from [X] and inferior laryngeal vessels enter larynx
Pharyngeal tonsil
On roof of nasopharynx is pharyngeal (adenoid) tonsil
Enlarged adenoids –> fill nasopharynx and blocks nasal cavity, can also block Eustachian tube (which goes from nasal cavity to middle ear) –> middle ear infection, cannot breathe through nose, loud breathing
Pharynx blood supply and venous drainage
Blood supply:
Upper part - supplied by branches of ext carotid (lingual, maxillary, facial a)
Lower part - branches of subclavian a (inf thyroid a of thyrocervical trunk)
(major blood supply to palatine tonsil is tonsillar branch from facial artery)
Venous drainage:
Superiorly veins drain into pterygoid plexus and inferiorly to facial and internal jugular v
Lymphatic drainage of pharynx
Runs w internal jugular v
Lymphatic vessels drain into deep cervical lymph nodes (paratracheal, infrahyoid, retropharyngeal nodes)
(palatine tonsils drain into jugulodigastric nodes)
Innervation of pharynx
Motor and sensory mainly by pharyngeal plexus (branches of vagus and glossopharyngeal n)
Motor: all muscles innervated by [X] except stylopharyngeus which is innervated by [IX]
Sensory:
Nasopharynx - [V2]
Oropharynx - [IX]
Laryngopharynx - [X]
Mucosal features of pharynx
Nasopharynx:
- Pharyngeal tonsil, opening of Eustachian tube, torus tubularis, salpingopharyngeal fold and pharyngeal recess
Oropharynx:
- Palatopharyngeal arch, palatine tonsil, palatoglossal arch
Laryngopharynx:
- Laryngeal inlet
General structure of larynx
Musculoligamentous structure w cartilaginous framework located above lower resp tract
Protects airway and involved in phonation
Continues inferiorly with trachea and superiorly opens into laryngopharynx
Larynx components
Cartilages: epiglottis, cricoid, arytenoid, corniculate, cuneiform
Ligaments and fibroelastic membranes: thyrohyoid membrane w its ligaments, hyo-epiglottic lig, cricotracheal lig, cricothyroid membrane w its lig and quadrangular membrane w its lig
Muscles: intrinsic and extrinsic
Larynx - cricoid cartilage
From C6 vertebral level
Thickened posteriorly
Made up of arch and lamina
Superiorly has 2 facets for articulation with arytenoid cartilage
Larynx - extrinsic membrane
= Thyrohyoid membrane (from lower part of hyoid bone to upper part of thyroid cartilage)
Aperture for internal branch of superior laryngeal n and associated artery
(sup laryngeal originates from sup thyroid a and supplies upper part of larynx and thyroid, inf thyroid a supplies lower part)
Larynx - Intrinsic membranes
(deep to thyroid cartilage)
Cricothyroid ligament:
- Where it thickens at upper border = vocal ligament (true vocal cord)
Quadrangular membrane:
- Where lower part is thickened = vestibular ligament (false vocal cord)
Vocal cords relation to arytenoid cartilage
Vocal ligament (true) runs from anterior thyroid cartilage to arytenoid cartilage Vestibular ligament (false) runs from anterior thyroid cartilage to arytenoid cartilage
Vestibular lig (false) more lateral then vocal lig
When arytenoid moves, vocal cords open/close
To breath - abduct/externally rotate arytenoid to open vocal cords
Adduct to talk
Piriform recess
Piriform recess lies either side of laryngeal inlet, bound medially by aryepiglottic fold and laterally by thyroid cartilage.
Common place for food and foreign bodies to become trapped (e.g. fish bone)
i.e. to locate food go lateral to aryepiglottic fold
In newborn - majority of larynx is piriform recess (drink milk lying down, recess acts as gutter towards oesophagus)
Intrinsic muscle of larynx
Cricothyroid muscle with straight and oblique parts
Most important extrinsic muscle of larynx
Posterior crico-arytenoid muscle
ONLY muscle that abducts the ligaments to keep the airways open
Innervated by damage to recurrent laryngeal nerve (from vagus n)
- Damage on 1 side = hoarseness of voice
- Damage on both sides = cannot breathe
Blood supply to larynx
Above vocal cords:
Larynx supplied by sup laryngeal a (from sup thyroid a)
Below:
Larynx supplied by inf laryngeal a (from inf thyroid a)
Removing thyroid - must ligate sup thyroid right at gland (if you ligate at origin from ext carotid there will be no supply by sup laryngeal to larynx)
Venous drainage of larynx
Inferior and superior thyroid veins
Innervation
Sensory:
Above vocal cords - sup laryngeal gives off internal laryngeal n
Below vocal cords - recurrent laryngeal n (from vagus n)
Motor :
All muscles of larynx innervated by vagus [X]
