L2 - Flashcards
What features does the pharynx extend to and from
Extends from the base of the skull to the lower border of the cricoid cartilage (C6)
What shape is the pharynx
Funnel shaped
what are the 3 parts of the pharynx
- Nasopharynx (air)
- Oropharynx (air + food)
- Laryngopharynx ( air and food sent in separate directions – food into the oesophagus, air into the larynx)
what is the pharynx continuous with?
The oesophagus
What is above, behind and on each side of the pharynx?
Above: The base of the skull
Behind: The bodies of the 6 upper cervical vertebra –> function to protect the pharynx
On each side:
- Great vessels and nerves of the neck –> Common carotid artery, IJV and vagus n. and others ig
- Styloid process and its associated structures
What are tonsils and what are the types of tonsils?
They are masses of lymphoid tissue (contains immune cells - B cells mainly i think) associated with the pharynx
Types:
- Nasopharyngeal tonsils (Adenoids) –> in roof of nasopharynx
- Palatine tonsils –> behind oropharynx/mouth
- Lingual tonsils –> behind the tongue at the base
Form a ring of defense against pathogens in the mouth
Walls/layers of the pharynx?
From the inside to outside - 5 layers :
1) mucous membrane
2) submucosal coat
3) Pharyngobasilar fascia - lining inside muscles
4) pharyngeal muscles
5) fascia - lining outside the muscles
What is the role of fascia in the pharynx?
It reinforces the larynx wall especially the spaces deficient in muscle (like the gaps thru which different structures leave the pharynx)
Are the pharyngeal musc. striated or unstriated? How many layers? what are they?
Where are the striated muscles arranged in the opp. way?
Striated but no evident voluntary control
- striated musc. arranged in 2 layers
- Outside - circular muscle (OC - remember the shit show cindy loves)
- Inside - longitudinal muscle
In the GIT -
Outside: Longitudinal muscles
Inside: Circular muscles
What are the pharyngeal muscles?
What are their origins?
What are their insertions?
What is their function?
What is their nerve supply?
NERVE SUPPLY –> all by Vagus nerve except stylopharyngeus muscle which is by glossopharyngeal nerve
Longitudinal muscles: Responsible for the elevation of the pharynx during swallowing
– Salpingopharyngeus (Origin - cartilage of Auditory tube/pharyngotympanic tube)
– Palatopharyngeus (origin - aponeurosis of soft Palate)
– Stylopharyngeus (origin - Styloid process)
Insertion (common): wall of pharynx
Circular muscles (3 constrictors): Responsible for constriction of pharynx
– Superior constrictor (Origin - Pterygoid hamulus, pterygomandibular raphe, mandible)
– Middle constrictor (Origin - Hyoid bone)
– Inferior constrictor (Origin - cricoid and thyroid cartilages of larynx)
Insertion (common) : Pharyngeal Raphe
What is the insertion for all the longitudinal musc? and circular muscles?
Longitudinal – wall of the pharynx
Circular (constrictor musc.) – Pharyngeal raphe (median fibrous raphe)
Which muscle has the cartilage of the auditory tube as an origin?
salpingopharyngeus musc.
(origin - auditory tube/pharyngotympanic tube)
Which pharyngeal muscle originates from the hyoid bone?
The middle constrictor muscle
Which muscles originate from cartilages in the pharynx and which cartilages?
Inferior constrictor musc –> cricoid and thyroid cartilages
Salpingopharyngeus musc –> Cartilage of the auditory/pharyngotympanic tube
where does the raphe extend from?
The skull
Which musc is innervated by the glossopharyngeal n. in the pharynx?
The stylopharyngeus
What allows for gaps in the wall of the pharynx?
What reinforces these gaps?
The overlapping of muscles (since they’re stacked like flower pots) allows for gaps in the wall
Allows for structures including nerves and vessels to pass thru
Fascia reinforces these gaps in the wall
Describe the motor and sensory innervation of the pharynx
Mostly thru the pharyngeal plexus (Vagus nerve - CN X and the glossopharyngeal nerve - CN IX)
Motor innervation:
- All by muscles by vagus nerve (CN X) except for the stylopharyngeus musc which is by the glossopharyngeal nerve (CN IX)
Sensory innervation:
- Nasopharynx: Maxillary nerve (V2 - trigeminal nerve)
- Oropharynx: Glossopharyngeal (CN IX)
- Laryngopharynx: Vagus (CN X) via the internal branch of the superior laryngeal nerve
What is the test commonly used for the glossopharyngeal nerve functioning (CN IX)
The gag reflex
- CN IX innervates the oropharynx
- Touch the back of the oropharynx/tongue
- Causes a reflex involving the symetrical elevation of the uvula
Describe the gag reflex pathway and name the nerves it can be used to test
Can be used to test for the glossopharyngeal and the vagus nerves
Reflex Pathway:
AFFERENT: Glossopharyngeal nerve provides sensory and afferent innervation to the posterior third tongue/oropharynx (sends msgs to the brain)
EFFERENT: The vagus nerve provides motor innervation to most of the pharyngeal muscles and palate
Thus msgs sent thru this nerve to elevate uvula
Location of the nasopharynx. oropharynx and laryngopharynx?
naso –> Lies behind the nasal cavity (chonae)
and above the soft palate
Oro –> Lies behind the oral cavity
Extends from the level of the soft palate (roof of mouth) to the upper margin of the epiglottis (cartilage of the larynx)
Laryngo –> Lies posterior to the larynx
Extends from the upper margin of the epiglottis and to the beginning of the oesophagus, anterior to the 6th cervical vertebra
Where does the opening of the pharyngotympanic tube lie?
in the lateral wall of the nasopharynx
alternate names for the auditory tube?
pharyngotympanic tube
eustachian tube
What is the function of the auditory tube?
The pharyngotympanic tube connects the nasopharynx with the middle ear
It thus allows ventilation of the middle ear and also functions to maintain equal air pressure between the outer and middle ear on either side of the eardrum.
