From where to where does the pharynx extend to, anteriorly and posteriorly?
From cranial base to inferior border of cricoid cartilage anteriorly
And Inferior border of C6 posteriorly.
What 3 parts is the pharynx divided into?
What type of epithelium does each part of the pharynx have?
Nasopharynx - pseudostratified ciliated with goblet cells
Oropharynx - Stratified squamous non keratinised
Laryngopharynx - Stratified sqmaous non keratinised
From where to where does the nasopharynx extend?
top of pharynx to bottom of soft palate/uvula.
Why might an infection lead to blockage of the eustachian tube? What disease does this lead to?
Lymphoid tissue forms a Tonsillar ring around the superior part of the pharynx, which aggregates to form the Adenoids. The adenoids may become swollen during infection in children
Leads to otitis media
From where to where does the oropharynx extend?
Soft palate to superior border of epiglottis
From where to where does the laryngopharynx extend?
superior border of epiglottis to inferior border of cricoid cartilage
what are the two muscular layers of the pharynx?
outer circular muscle layer and inner longitudinal mucle layer.
What is the function and action of the outer circular muscle layer of the pharynx?
During swallowing the muscle constrict to propel the bolus of food downwards. Muscles overlap each other to achieve this.
What are the 3 muscles of the inner longitudinal muscle layer? What is their function?
Act to shorten and widen pharynx
How is the pharynx innervated? and how is this plexus formed?
Pharyngeal plexus - formed from vagus, glossopharyngeal, and sympathetic fibres from superior cervical ganglion
What is the motor innervation of the pharynx?
Except stylopharyngeus muscle which is glossopharyngeal nerve
Describe the voluntary and pharyngeal phase of swallowing
- Tongue moves the bolus back onto the pharynx
Pressure receptor in palate triggers:
- Inhibition of breathing
- Raising of the larynx – Suprahyoid and Longitudinal Muscles
- Closure of the glottis
- Opening of the upper oesophageal ‘sphincter’
What are the arteries that supply the pharynx? Which artery do they originate from?
From external carotid:
- Ascending pharyngeal
What is the venous drainage of the pharynx?
Pharyngeal venous plexus --> internal jugular vein
What clinical features can occur in enlarged adenoids?
- Nasal obstruction
- Mouth breathing, nasal speech
- Feeding difficulty (especially infants)
- Snoring / Obstructive Sleep Apnoea
- Block the opening of the Eustachian Tube
During what ages is the maximal size for adenoids?
3-8 then regression
Where does the palatine tonsils lie?
lies between palatoglossal arch and palatopharyngeal arch
What is the lymphatic drainage of the palatine tonsils?
Jugulo-digastric (tonsillar) node
What is quinsy? How is it treated?
Peritonsillar abscess pushing uvula to other side
Name the 3 regions food is likely to become stuck in the oropharynx
- Vallecula - pouch between tongue and epiglottis
- Base of tongue
- Region of palatine tonsil
Name the 2 regions food is likely to become stuck in the layngopharynx