Sem 2 - Z - Pharynx & Pre-vertebral region - Pharynx divisions/muscles/vasculature/plexus, Pre-vertebral muscles, ganglia Flashcards
When does the pharynx become the oesophagus? What can help to identify this change?
The pharynx becomes the oeosophagus at the level of the C6 vertebrae - identifying the cricopharyngeus part of the inferior constrictor muscle can help identify this level
What is the change in epithelium from pharynx to oesophagus?
The pharynx is lined by ciliated columnar epithelium superiorly which changes to stratified squamous epithelium inferiorly
Underneath the epithelial layer of the pharynx, is the fibrous layer followed by the muscular layer
What does the fibrous layer of the pharynx attach to superiorly and inferiorly?
Fibrous layer of the pharynx under the epithelium attaches from the skull base and into the submucous coat of the oesophagus inferiorly
- Grey is the fibrous layer in pic
The fibrous coat between the epithelium and muscular layer of the pharynx is known as the pharyngobasilar fascia Where exactly does this insert into the skull?
The pharyngobasilar fascia inserts into the basilar portion of the occipital bone and into the submucous coat of the oesophagus inferiorly
What are the two muscular layers of the pharynx?
We have the outer almost circular constrictor muscle layer and inner longitudinal muscle layer
- What does the nasopharynx lie between?
- What does the oropharynx lie between?
- What does the laryngopahrynx lie between?
- The nasopharynx extends from the base of the skull to the soft palate
- The oropharynx lies behind the oral cavity from the uvula to the epiglottis
- The laryngopharynx extends from the superior border of the epiglottis to the inferior border of the cricoid cartilage
What bones make up the roof of the nasopharynx? What else is in the roof of the nasopharynx?
What makes up the floor of the nasopharynx? What is anterior to the nasopharynx?
The sphenoid bone and the occipital bone make up the roof of the nasopharynx along with the pharyngeal tonsil
The floor of the nasopharynx is made up of the soft palate and the pharyngeal isthmus Anterior to the nasopharynx is the nasal cavity
What makes up the lateral wall of the nasopharynx?
What makes up the posterior wall of the nasopharynx?
The auditory/eustachian/pharyngotympanic tube and the salpinogpharyngeal fold
The posterior wall of the nasopharynx is fomed partly by the roof and the C1 vetebrae
What forms the roof and floor off the oropharynx?
Oropharynx
- Roof - soft palate
- Floor - posterior 1/3rd of tongue, lingual tonsil and glossoepiglottic fold
What forms the anterior, posterior and lateral borders of the oropharynx?
- Anterior - oral cavity
- Posterior - C2/3 vertebral level
- Lateral - palatoglossal and palatopharyngeal arches with the palatine tonsil between the two
What forms the anterior and posterior borders of the laryngoparhynx?
Superior is oropharynx Inferior is oesophagus
Anterior border - larynx Posterior border - C3-C6 vertebrae
What supports the lateral wall of the laryngopharynx?
Laterally it is supported by the thyroid cartilage, aryepiglottic fold and thyrohyoid membrane
Pharynx comes down from base of the skull and blends in to the oesophagus around C6 vertebral level
- Epithelial layer, then fibrous then muscular (outer almost circular constrictor layer and inner longitudinal layer)
- * What are the three paired pharyngeal constrictor muscle names?
- * What do they insert into posteriorly?
- * What is the main function of the three pharyngeal constrictor muscles?
- The three paired constrictors are known as the superior, middle and inferior constrictor muscle
- They insert posteriorly into the median pharyngeal raphe
- The pharyngeal constrictor muscles contract to narrow the pharynx lumen &propel the bolus of food inferiorly
What is the origin of the superior pharyngeal constrictor muscle?
Superior pharyngeal constrictor
- Attaches from the lower, posterior part of the medial pterygoid plate of the sphenoid bone, the pterygoid hamulus, the ptergyomandibular ligament (aka as pterygomandibular raphe), the mandible and the side of the tongue
What is the insertion of the superior pharyngeal constrictor?
The superior pharyngeal constrictor inserts into the pharyngeal tubercle of the occiput, fibrous raphe and middle constrictor
What is the function of the superior pharyngeal constrictor?
What is it innervated by?
- Superior pharyngeal constrictor upper fibres pull the posterior pharyngeal wall anteriorly to close the nasopharynx during swallowing
- They also contract to propel the bolus of food inferiorly to the middle pharyngeal constrictor
- Innervated by the vagus nerve in the pharyngeal plexus
RESTATE the attachment, function and innervation of the superior pharyngeal constrictor muscles
Attachment - lower posterior part of the medial pterygoid plate, pterygoid hamulus, pterygomandibular ligament, mandible and side of the tongue
- Inserts into the pharyngeal tubercle of the occipital bone, fibrous pharyngeal raphe and middle constrictor
- Function - upper fibres pull the pharynx anteriorly during swallowing to close the nasopharynx, fibres also propel bolus of food inferiorly to the middle pharyngeal constrictor
- Innervation - CN X in the pharyngeal plexus
What is the attachment of the stylohyoid ligament?
The stylohyoid ligament attaches from the styloid process of the temporal bone to the lesser cornu (lesser horn) of the hyoid bone
What is the attachment of the middle pharyngeal constrictor muscle?
Middle pharyngeal constrictor attaches from the lower part of the stylohyoid ligament, the greater and lesser cornu of the hyoid bone to the pharyngeal raphe and blends with superior and inferior pharyngeal constrictors
What is the function and innervation of the middle constrictor?
Function - to propel the bolus of food into the inferior constrictor muscle
Innervation - CN X in the pharyngeal plexus
RESTATE the attachment, function and innervation of the middle pharyngeal constrictor
Attachment - lower part of the stylohyoid ligament and greater and lesser cornu of the hyoid bone
- Inserts into the pharyngeal raphe and blends with the superior and inferior constrictor muscles
Function - Propels bolus of food into inferior constrictor muscle
Innervation - CN X in pharyngeal plexus
State the attachment of the inferior pharyngeal constrictor muscle?
Inferior pharyngeal constrictor attaches from the lamina of the thyroid and cricoid cartilage to the pharyngeal raphe and blends with the middle pharyngeal constrictor and oesophagus
What is the difference in the orientation of fibres and their names in the inferior constrictor?
Upper fibres are orientated in the same direction as the middle constrictor (oblique) and arise from the lamina of the thyroid cartilage - known as thyropharyngeus
Lower fibres attach from the lamina of the cricoid cartilage and are more circular (horizontal) almost forming a sphincter around the pharynx - known as cricopharyngeus
What is the function of the inferior constrictor and what is the nerve supply?
Inferior constrictor propels bolus of food into the oesophagus.
Cricopharyngeus is thought to have a sphincter effect preventing the entry of air into the oesophagus between swallowing acts.
- Thyropharyngeus - CN X in the pharyngeeal plexus
- Cricopharyngeus - External laryngeal nerve from the superior laryngeal nerve branch of the vagus nerve
Describe the attachment and route of the stylopharyngeus muscle
Stylophayngeus arises at the styloid process of the temporal bone
- It travels across the internal carotid artery and between the superior and middle constrictor muscles to insert onto the posterior border of the thyroid cartilage
State the function and innervation of the stylopharyngeus?
Stylopharyngeus elevates the larynx and pharynx during swallowing It is innervated by CN IX
State the attachment, function and innervation of the salpingopharyngeus
Salpingopharyngeus
- Attaches from the cartilage of the pharyngotympanic tube and blends with the palatopharyngeus
- Function - elevates the pharynx
- Innervation - CN X in the pharyngeal plexus
State the attachment, function and innervation of the palatopharyngeus
Palatopharyngeus
- Attaches from the hard palate and palatine aponeurosis to the posterior lamina of the thyroid cartilage
- Function - elevates the pharynx
- Innervation - CN X in the pharyngeal plexus
Constrictor muscles and longitudinal muscles will raise pharynx up and close off the nasopharynx area
- What is the little piece of elastic cartilage that will bend and close the laryngeal inlet when a bolus of food comes into contact with it?
This is the epiglottis
What is the nerve which passes underneath the inferior constrictor muscle to enter the larynx? What does it innervate?
The recurrent laryngeal nerve branches from the vagus nerve and ascends in a groove between the trachea and oesophagus before entering the larynx underneath the inferior constrictor to supply the intrinsic muscles of the larynx .
- EXCEPT THE cricothyroid muscle which is innervated by the external laryngeal nerve
There is a ringed arrangement of lymphoid tissue within the pharynx surrounding the naso and oropharynx What is this ringed arrangement known as and what tonsils make it up? Where is each tonsil located?
Waldeyer’s ring
- Pharyngeal tonsil - in the roof of the nasopharynx beneath the sphenoid bone
- Tubal tonsils - where each auditory tube opens into the lateral wall of the nasopharynx
- Palatine tonsils - between the palatoglossal and palatopharyngeal arches
- Lingual tonsil - at the posterior aspect of tongue
Motor and sensory innervation of the majority of the pharynx (except nasopharynx) is achieved by the pharyngeal plexus. (except stylopharyngeus and cricopharyngeus)
- What muscle does the pharyngeal plexus mainly overly and what is the plexus made from?
Pharyngeal plexus mainly overlies the middle pharyngeal constrictor muscle
Contributions from the glossopharyngeal nerve (sensory), vagus nerve (sensory+motor) and sympathetics from the superior cervical ganglion
What is the arterial supply to the pharynx?
Pharyngeal arteries from the pterygopalatine part of the maxillary artery
Ascending pharyngeal artery from the deep (medial) surface of the external carotid artery
Once sectioning through the trachea and the oesophagus, we will come to the carotid sheaths
- What is the layer of fascia covering the longus colli and capitis known as?
- What are the 4 anterior prevertebral muscles?
Layer of fascia covering the longus colli and capitis is known as the prevertebral fascia of the neck - covers the cervical vertebrae, postural neck muscles and the anterior prevertebral neck muscles:
- Longus colli
- Longus capitis
- Rectus capitis anterior
- Rectus capitis lateralis
Longus capitis is superficial to the longus colli
- What is the attachment of the longus capitis?
Longus capitis attaches from the anterior tubercles of transverse process C3-6 to the basilar aspect of the occipital bone
What is the attachment, function and innervation of the longus capitis?
- Attachmnet - Anterior tubercles of transverse processes C3-C6 to the basilar aspect of the occipital bone
- Function -Flexion of the head
- Innervation - Ventral rami of spinal nerves C1-3
Longus colli can be split into superior oblique, inferior oblique and vertical parts spanning from atlas (C1) to T3 vertebrae
- What are the attachments of each of the longus colli parts?
- Superior oblique - attaches from anterior tubercles of transverse processes C3-5 to the anterior atlantal tubercle
- Inferior oblique - attaches from T2/3 vertebral bodies to the anterior tubercles of transverse processes C5/6
- Vertical - attaches from T1,2,3 vertebral bodies to C4,5,6 vertebral bodies
What is the function and innervation to the longus colli?
- Function - Flexion of the neck Rotation of head to the opposite side via ipsilateral inferior oblique
- Innervation - Ventral rami of cervical spinal nerves C2-6
What is the nerve supply to both the rectus capitis anterior and lateralis?
Both the rectus captitis anterior and lateralis are supplied by the loop between the ventral rami of cervical nerves C1 and C2
What is the attachment and function of the rectus capitis anterior?
- Attaches from the anterior surface and root of the transverse process of the atlas to the occipital bone anterior to the occipital condyles
- Function - Flexion of the atlanto-occipital joint
What is the attachment and function of the rectus capitis lateralis?
Rectus capitis lateralis
- Attaches from the transverse process of the atlas to the occipital bone at the inferior the surface of the jugular process of the occipital bone
- Lateralis causes lateral flexion of the head
Which vein crosses the rectus capitis lateralis?
The internal jugular vein crosses the anterior aspect of the rectus capitis lateralis after exiting the skull via the jugular foramen
Where does the sympathetic chain begin?
The sympathetic chain begins fro the base of the sull and will end at the ganglion impar (merging of the two chains inferiorly)
- What structures does the sympathetic chain travel behind in the cervical region?
- What two fascial sheaths does the sympathetic chain lie between?
The sympathetic chain travels behind the ICA and CCA medial to the vagus nerve in the cervical region It lies in a deep fascia between the carotid sheath and the prevertebral fascia over the surface of longus capitis and colli
Where is the superior cervical ganglion located? What ventral rami does it communicate with?
Where is the middle cervical ganglion located? What ventral rami does it communicate with?
The superior cervical ganglion is large and located immediately below the skull. It communicates with C1-4 ventral rami
The middle cervical ganglion is small and located at the level of the cricoid cartilage It communicates with C5,6 ventral rami
Which artery is the middle cervical ganglion located close to?
The middle cervical ganglion is closely related to the loop of the inferior thyroid artery
What gland does the middle cervical ganglion give branches to and how do these branches reach the gland?
What branches does the middle cervical ganglion give to the cardiac plexus?
Due to the close relation to the inferior thyroid artery, the middle cervical ganglion gives branches which travel on this artery to innervate the thyroid gland with sympathetics
The middle cervical ganglion gives the middle cardiac branch to the cardiac plexus
The middle cervical ganglia is usually connected to the inferior cervical ganglia by 2 or more nerve bundles
What is the anterior nerve bundle connecting the two known as and what is its path?
The anterior nerve bundle connecting middle and inferior cervical ganglia is known as the Ansa subclavia
- It forms a loop anterior to the 1st part of the subclavian artery and then travels back up towards the inferior cervical ganglion
Where is the inferior cervical ganglion usually located? What is it often fused with?
The inferior cervical ganglion is located posterior to the vertebral artery between the transverse process of C7 and the head of the first rib It is usually fised with the 1st thoracic ganglion forming the stellate ganglion
- What branch does each cervical ganglion give to the cardiac plexus?
- What arteries does branches from the inferior cervical ganglion travel on?
Superior, middle and inferior cervical ganglion give the superior, middle and inferior cardiac nerve branch respectively to the cardiac plexus located in the thorax
- Inferior cervical ganglion also gives arterial branches to the vertebral and subclavian arteries
