Pharynx

Question 1

Features of Pharynx

Answer 1

• Extends from skull base to inferior border of cricoid cartilage (level of C6)
• Consists of circular & longitudinal mm. wrapped in fascia
• Lined with mucous membrane containing mucous glands

Question 2

Nasopharynx borders

Answer 2

• Posterior extension of nasal cavities
• Between skull base & soft palate
• Passes thru 2 nasal apertures or choanae
– Separated by bony nasal septum
• Choanae bounded laterally by nasal conchae

Question 3

Nasopharynx structures

Answer 3

• Auditory (Eustachian or pharyngotympanic) tube orifice – posterior to inferior concha
– Serves as connection between pharynx & middle ear
• Torus tubarius – posterior to auditory tube
orifice (cartilage of auditory tube)
• Pharyngeal recess – posterior to torus tubarius
– Groove along lateral pharyngeal wall
• Pharyngeal tonsil – postero-superior to torus
tubarius
• Salpingopharyngeal fold – mucous membrane covering the salpingopharyngeal m.

Question 4

Oropharynx borders

Answer 4

• Posterior extension of oral cavity
• Between soft palate & epiglottis
• Passes thru 2 sets of arches laterally – Palatoglossal arch
– Palatopharyngeal arch
• Palatoglossal arch separates oral cavity & oropharynx

Question 5

Oropharynx structures

Answer 5

• Palatoglossal arch – mucosal fold over palatoglossus m.
• Palatopharyngeal arch – mucosal fold over palatopharyngeus m.
• Palatine Tonsil – in tonsillar bed between 2 palatine arches

Question 6

Laryngopharynx borders

Answer 6

• AKA hypopharynx
• Posterior extension of laryngeal cavity
• Between epiglottis & cricoid cartilage
• Passes posteriorly from aditus (inlet) of larynx
• Surrounded by piriform recesses

Question 7

Laryngopharynx structures

Answer 7

• Piriform recess – extends laterally to thyroid cartilage
• Internal laryngeal n. – descends beneath mucous membrane
• Superior laryngeal vessels – run with internal laryngeal n.
• Recurrent laryngeal n. – ascends beneath mucous membrane
• Inferior laryngeal vessels – run with recurrent laryngeal n.

Question 8

Superior Constrictor m.

Answer 8

• Arises from pterygomandibular raphe & medial pterygoid plate & mandible
• Meets buccinator m. anteriorly
• Anchored to pharyngeal tubercle of skull superiorly

Question 9

Middle Constrictor m.

Answer 9

• Arises from greater horn of hyoid bone & inferior porLon of stylohyoid ligament
• Overlaps superior constrictor m.
• Stylopharyngeus m & CN IX pass between supr. & middle constrictor mm.

Question 10

Inferior Constrictor m.

Answer 10

• Arises from thyroid & cricoid carLlages
• Overlaps middle constrictor m.
• Internal laryngeal n. & superior laryngeal a. pass between middle & inferior constrictor mm.
– Then these pierce thyrohyoid membrane

Question 11

Stylopharyngeus m. and Salpingopharyngeus m.

Answer 11

• Stylopharyngeus m. -­‐ arises from styloid process
– Descends to blend with fibers of lower constrictor mm.
• Salpingopharyngeus m. – arises from auditory tube
– Descends to blend with fibers of palatopharyngeus m.
– Covered by salpingopharyngeal fold of mucosa

Question 12

Palatopharyngeus m. and Palatoglossus m.

Answer 12

• Palatopharyngeaus m. -­‐ arises from soU palate – Descends along lateral wall of pharynx
• Palatoglossus m. – arises from soU palate
– Descends to juncLon of anterior 2/3 & posterior
1/3 of tongue
• These make up the tonsillar pillars – Surrounding the tonsillar bed

Question 13

Pharynx: Arterial Supply

Answer 13

• Predominantly via ascending pharyngeal & superior thyroid aa. (brs. of ECA)
• Additional supply via brs. of facial & maxillary aa. (brs. of ECA)

Question 14

Pharynx: Venous drainage

Answer 14

• Predominantly via pharyngeal plexuses of vv. – External & Internal plexuses surrounding
constrictor mm.
• Anastomoses with pterygoid plexus, superior thyroid, lingual, facial & IJV

Question 15

Pharynx: Innervation

Answer 15

• Supplied via pharyngeal plexuses of nn.
– Superior cervical ganglion – supplies symp. nn. to
plexus
– CN X – supplies motor to pharyngeal mm.
– CN IX – supplies motor to stylopharyngeus m & sensory to pharynx

Question 16

Clinical notes: Innervation

Answer 16

• Loss of motor nn. to pharynx leads to marked dysphagia (difficulty swallowing)
• Loss of sensory nn. to pharynx may cause loss of gag reflex

Question 17

Clinical notes: Pharyngeal Tonsil

Answer 17

• Consists of lymphoid Lssue in roof of nasopharynx
• When enlarged, referred to as adenoids
• Large adenoids obstruct air flow from nose to
nasopharynx
– Makes mouth breathing necessary
– May also impinge upon torus turbarius & auditory tube orifice
– Obstructs air exchange between nasopharynx & middle ear

Question 18

Clinical notes: Piriform Recess

Answer 18

• Accidentally swallowed objects may become trapped here
• Induce choking sensation & severe coughing
– Due to stimulation of int. & rec. laryngeal nn.
• Sharp objects may pierce mucosa – Leads to infection
– Injures underlying nn. &/or vessels