16 - Head + Neck - Pharynx Flashcards
The pharynx extends from the base of the skull to which vertebral level?
C6
What are the 3 parts of the pharynx, and their associated vertebral levels?
C1 = Nasopharynx C2-3 = Oropharynx C3-6 = Laryngopharynx
What is the inferior border of the nasopharynx?
Soft palate
What are the superior and inferior borders of the oropharynx?
Sup: Soft palate
Inf: Sup. border of the epiglottis
What are the superior and inferior borders of the laryngopharynx?
Sup: Sup. border of the epiglottis
Inf: Inf. border of cricoid cartilage
What type of epithelium lines the naso-, oro- and laryngo-pharynx?
Naso- Ciliated pseudostratified columnar epithelium + goblet cells
Oro- Stratified squamous epithelium
Laryngo- Stratified squamous epithelium
What are the piriform fossae?
Small depressions either side of the laryngeal inlet
- Common site of trapped food and cancers
Which muscles elevate the larynx during swallowing?
- Suprahyoids
- Longitudinal pharyngeals
What are the main functions of the internal longitudinal muscles of the pharynx?
- Shorten and widen pharynx
- Elevate larynx during phonation + swallowing
Name the internal longitudinal muscles of the pharynx:
- Stylopharyngeus
- Palatopharyngeus
- Salpingopharyngeus
What is the main function of the outer circular muscles of the pharynx?
Contract sequentially to propel food into oesophagus
Name the outer circular muscles of the pharynx:
Superior, Middle and Inferior pharyngeal constrictors
Killian’s dehiscence is an area of weakness between which pharyngeal muscles?
What is the clinical relevance of this?
- Between the 2 muscle belly’s of the inferior pharyngeal constrictor
- Pharyngeal mucosa can herniate through weakness to form a pharyngeal pouch, resulting in dysphagia, regurgitation and halitosis
Why is a pharyngeal pouch a ‘false’ diverticulum?
It does not contain all layers of the pharynx (mucosa only)
Which nerve innervates all the pharyngeal muscles except one? What is the exception?
CN X
Exception = Stylopharyngeus = CN IX
Which nerves give sensory fibres to the pharynx?
Naso- = CN V2 Oro- = CN IX Laryngo- = CN X
What implications can the adenoids cause if they become chronically inflamed?
- Mouth breathing
- Snoring
- Nasal tone to speech
- Otitis media (block ET)
What is the arterial supply to the palatine tonsils?
Facial artery (tonsillar branch)
What structures are vulnerable during a tonsillectomy?
- Facial artery (tonsillar branch)
- Internal Carotid artery
- CN IX
What are the 3 phases of swallowing?
1) Oral
2) Pharyngeal
3) Oesophageal
What is the function of the supra- and infrahyoid muscles during swallowing?
Suprahyoids contract:
- Elevate larynx
- Close epiglottis
- Protect airways
Infrahyoids partially contract to stabilise actions of suprahyoids.
Which lymph nodes would you expect to be swollen if a patient had tonsillitis? Describe their location:
Jugulo-digastric
- Posterior and inferior to the angle of the mandible
What causes ‘glue ear’ and why does this predispose to ear infections?
- Eustachian tube dysfunction (^adenoids, tumour, allergens)
- Middle ear cannot equalise with atmospheric P
- Middle ear cells absorb N2 + O2 = negative P
- Causes accumulation of transudate
- Favourable environment for bacteria
Which layer of cervical fascia envelops the thyroid gland?
Pre-tracheal fascia
The thyroid gland sits at which vertebral levels?
C5 - T1
Why does the thyroid gland move during swallowing?
It is connected to the Cricoid cartilage via dense connective tissue
The thyroid gland lies deep to which infra-hyoid muscles?
- Sternohyoid
- Sternothyroid
Describe the arterial supply of the thyroid:
- Sup. poles = Sup. Thyroid arteries
- Inf. poles = Inf. Thyroid arteries
What are the main complications of a Thyroidectomy?
- Bleeding
- Injured recurrent laryngeal nerve
- Injured superior laryngeal nerve
- Hypoparathyroidism
- Hypothyroidism
- Infection
What is the function of the suprahyoid muscles?
Elevate hyoid bone = elevates larynx to allow swallowing
Is digastric a supra- or infrahyoid muscle? Name the nerve which innervates it:
Suprahyoid muscle
CN V3
What are the origins and insertion of the digastric muscle?
Origins:
- Ant. belly = Digastric fossa of mandible
- Post. belly = Mastoid process
Insertion: Hyoid bone
What is the origin and insertion of omohyoid?
Origin: Scapula
Insertion: Hyoid
Is omohyoid a supra- or infrahyoid muscle? Name the nerve that innervates it:
Infrahyoid
Ansa cervicalis C1-C3
