L3 Flashcards
Boundaries of the pharynx: Posterior
Vertebral column and prevertebral muscles
What separates the pharynx from the cervical vertebra?
the prevertebral layer of deep cervical fascia
✨ the prevertebral fascia covers the prevertebral muscle,so from outside to inside you have:
Vertebral column>prevertebral muscle>prevertebral layer of fascia>buccopharyngeal fascia,which is fascia of the pharynx.
Boundaries of pharynx - superior?
Base of the skull which is formed by the sphenoid + occipital bones
Boundaries of pharynx - anterior
Continuous with nasal, oral, and larynx cavities
Boundaries of pharynx - inferior
esophagus (C6) + cricoidcartilage
Mention the attachments of the pharynx? 3p t m 3oid
- Medial pterygoid plate
- Pterygoid hamulus
- Pterygomandibular raphe
- Mandible
- Tongue
- Hyoid bone
- Thyroid cartilage
- Cricoid cartilage
Nasopharynx borders?
1-Roof/superior= pharyngeal tonsil (adenoid)
2-Lateral walls= tubal elevation (which has tubal tonsil) + tubal opening (opening of auditory tube) + pharyngeal recess (common site for carcinomas)
What makes the tubal opening in the lateral wall of pharynx?
produced by a muscle(salpingopharyngeus) and the medial end of auditory tube.
Common site for carcinomas in the nasopharynx?
Pharyngeal recess
Innervation of nasopharynx and types of epithelium?
Pharyngeal branch of pteryopalatine ganglion
Ciliated columnar to pseudo-stratified (cc ps)
Ooropharynx borders?
Anterior = oral cavity & palatoglossal arch Posterior = c2 c3 vertebra Laterally= tonsillar fossa occupied by palatine tonsil
What makes the tonsillar fossa?
Palatoglossal arch and palatopharyngeal arch ( between them palatine tonsil) mood
Innervation of ooropharynx?
Innervated by IX and X CN
9 10
Epithelium of ooropharynx
Lined by stratified squamous non- keratinized epithelium (ss)
Ooropharynx is from soft palate to epiglottis
Hehe
Laryngopharynx borders
Anterior = i c aryt ( inlet of larynx - cricoid cartilage - arytnoid cartilage) Posterior = c4 - c6 Lateral = piriform fossa
Epithelium and innervayof layrngopharynx
Ss nk
Innervation 9+10
What can happen in piriform fossa?
Food and bones can get stuck there
What can be injured during the removal of bone pieces from piriform fossa?
Internal Laryngeal n.
Structures of pharynx From inside to outside:
- Mucosa (The inner most layer)
- Submucosa
- Pharyngobasilar fascia (pharyngeal aponeurosis)
- Muscular layers (inner longitudinal and outer circular)
- Buccopharyngeal fascia
(The outer most layer)
Constrictor (circular) muscles of pharynx?
superior, middle and inferior constrictor (the cone )
Inferior constrictor has two parts- thyropharyngeus and cricopharyngeus
Origin and insertion of the circular constrictor muscles in the pharynx?
All of them take origin anteriorly and their fibers course laterally and posteriorly to the midline where they meet each other at the PHARYNGEAL RAPHE
There are two layers of muscles in GI
✨ in the pharynx:inner longitudinal ,outer circular
✨ in the rest of GI tract:outer longitudinal, inner circular
Where is the pharyngeal plexus
it lies in the posterior aspect of the middle constrictor muscle(not only the middle constrictor also the other constrictors but mainly the middle constrictor).
what are the nerves that contributes to pharyngeal plexus?
1-vagus 2- glossopharyngeal 3- sympathetic
the middle constrictor and the superior constrictor muscles are supplied directly by the vagus nerve through pharyngeal plexus.
A weak point in the posterior aspect of inferior constrictor muscle (thyropharyngeus) what’s this called?
killian’s dehiscence; weakness in the posterior lower aspect of the thyropharyngeus muscle
In the inferior circular constrictor muscle of the pharynx, aka he thyropharngeus, the posterior lower aspect is weak cuz its not covered by muscles = killians weak point
Info
normallly when you eat food, the thyropharyngeus will contract and the cricopharyngeus relax so that the food will move down.
✨ what will happen if the cricopharyngeus didn’t relax?
If the cricopharyngeus didn’t relax ,the food can form a diverticulum in the weak point(killian’s dehiscence) which will project posteriorly in the midline and this diverticulum is called zenker’s diverticulum which contains food material,and this diverticulum can be seen in barium X-ray.
Why does pharyngeal/zenker diverticulum happen?
1-Because of the neuronal incoordination between thyropharyngeus and cricopharyngeus.
2-the thyropharyngeus is supplied directly by vagus nerve through the pharyngeal plexus, whereas, the cricopharyngeus is supplied by recurrent laryngeal nerve, and although that the recurrent nerve is a branch of vagus but they have neuronal incoordination
Laimer’s traingle:
this is also a week point and you can see some time diverticulum that is produced by food.
Location:below the cricopharyngeus where the esophagus begins
Characteristics:there is only circular muscles and there is no longitudinal muscles.
Note:the esophagus has outer longitudinal and inner circular muscles)
Longitudinal muscle layer of pharynx
Salpingopharyngeus
Origin- cartilage of auditory tube Insertion-blends with palatopharyngeus
Palatopharyngeus
Origin-Hard palate and palatine aponeurosis
Insertion- thyroid cartilage and wall of pharynx
Stylopharyngeus
Origin- styloid process
Insertion- thyroid cartilage
Motor Innervation of pharynx?
All by vagus except stylopharyngeus by 9; glossopharyngeal
Parasympathetic Innervation of pharynx?
Facial = lesser petrosal
Esophagus extends from?
C6 + cricoid cartilage
In the neck- esophagus is related to?
Anterior: trachea, thyroid, recurrent laryngeal nerves
Posterior:prevertebral muscles and vertebral column
On each side: thyroid lobes and carotid sheath (which consist of common carotid,internal carotid,vagus,IJV)
Esophagus shows two curvatures,where?
the upper thorax(between T1 and T2)
lower thorax at T7
Both curvatures deviated to left
The esophagus pierces the diaphragm at the level?
at level T10 and becomes the abdominal part of the esophagus
Where are the esophagus constrictions located?
Cricopharynx - C6 - 15cm
Aortic arch - T4 - 25 cm
Lt bronchus - T5 - 28 cm
Esophageal hiatus (pierce diaphragm)- T10 - 40 cm
What is Barium swallowing(radiocontrast) used for?
Is used for taking X-ray for the esophagus
when the left atrium enlarges because of mitral stenosis it will compress the esophagus,so it is a pathological constriction.
Know that
Relationships of esophagus in the thorax
Anterior :
Trachea, left bronchus, right pulmonary artery, pericardium, left atrium
Posterior:
Vertebral column, thoracic duct, azygos vein, thoracic aorta
Abdominal esophagus is 1.25 cm long and enters stomach at
Level t11 (left 7th costal cartilage)
✨ the esophagus in the abdominal region (after esophageal hiatus) is covered by peritonium.
✨ the thoracic and cervical parts are covered by adventitia (not covered by peritoneum)
So?
because they are not covered by peritoneum, the metastasis of esophageal cancer is very common in these sites.
In the lower end of esophagus there is a Z-line,where the esophagus is continues with the stomach. What happens in the Z line?
in this line,the stratified squamous epithelium of esophagus immediately becomes simple columnar epithelium of the stomach.
✨ Z-line is common site for esophageal adenocarcinoma.
the epithelium lining the esophagus is?
stratified squamous non ketatinized epithelium .
there are two types of glands in the esophagus,and both of them have ducts and secrete mucin(mucous glands):
1-submucousal gland in the submucousa
»found every where
»_space;secrete acidic mucous
2-mucosal gland in the mucousa
»found in the lamina propria,and in the beginning and at the end of esophagus.
»they secrete neutral mucousa.
Note :the skeletal muscles (non voluntary)in the upper part of muscularis externa are supplied by recurrent laryngeal branch of vagus.
Note
Blood supply of esophagus?
Cervical esophagus = inf thyroid artery
Thoracic esophagus = bronchial artery + thoracic aorta
Abdominal esophagus = left gastric artery
Esophagus is attached to the margins of the esophageal hiatus by ?
phrenico-esophageal ligament
The ligament permits independent movement of the diaphragm and esophagus during respiration and swallowing
Venous drainage of esophagus?
Cervical esophagus = inf thyroid veins then to jugular system
Thoracic esophagus = azygos veins + hemi-azygos veins
Abdominal esophagus = left gastric vein (portal system)
esophageal varices
Anastomosis between the left gastric vein (portal system) and azygos vein
✨ in liver cirrhosis ,when portal hypertension occur, the blood flows in opposite direction and forms some accumulation in the lower part of esophagus .
Lymphatic drainage of esophagus?
Cervical esophagus = Inferior deep cervical lymph nodes
Thoracic esophagus = posterior mediastinal lymph nodes
Abdominal esophagus = Left gastric lymph nodes
Check the innervation of esophagus in the note
Check it
Sinus of Morgagni
Space between the superior constrictor, base of the skull and pharyngeal aponeurosis.
Nasopharyngeal carcinoma may invade laterally to this sinus resulting three symptoms (Trotter’s triad)-conductive deafness, ipsilateral paralysis of soft palate, and trigeminal neuralgia
Superior middle and thyropharyngeus are innervated by
Pharyngeal plexus thro vagus