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What are the borders of the anterior triangle?
- Anterior: midline of the neck
- Posterior: anterior border of sternocleidomastoid
- Superior: Inferior border of mandible
What two muscles subdivide the anterior tirangle?
Digastric and Omohyoid
What are the four subdivisions of the anterior triangle?
- 1. Submental triangle
- 2. Digastric triangle
- 3. Muscular triangle
- 4. Carotid triangle
The small veins found in the submental triangle unite to form what vein?Anterior jugular vein
What are the borders of the submental triangle?
- Inferior: hyoid bone
- Medial: midline of the neck
- Lateral: anterior belly of the digastric
What muscle forms the floor of the submental triangle?
What is another name for the digastric triangle?
What are the borders of the digastric triangle?
It is bounded by the inferior border of the mandible and the anterior and posterior bellies of the digastric
What muscles form the floor of the digastric (submandibular) triangle?
- 1. mylohyoid
- 2. hyoglossus
What gland occupies most of the digastric triangle?
What three major neurovascular structures are found in the digastric triangle?
- 1. Facial artery
- 2. Facial vein
- 3. hypoglossusal nerve (CN XII)
What triangle is bounded anteriorly by the midline of the neck, posterosuperiorly by the superior belly of the omohyoid, and posteroinferiorly by the sternocleidomastoid?
Which set of muscles are found in the muscular triangle?
What triangle is bounded posteriorly by the sternocleidomastoid, anterosuperiorly by the posterior digastric, and anteroinferiorly by the superior belly of the omohyoid?
What are the contents of the carotid sheath?
- 1. Common Carotid Artery (CCA) and its bifurcation
- 2. Internal Jugular Vein (IJV)
- 3. Vagus nerve (CN X)
What are the four major structures of the superficial layer of the anterior triangle?
- 1. Platysma
- 2. Cervical branch of the CN VII (motor to platysma)
- 3. Transverse cervical nerve (C2-C3)
- 4. Anterior jugular vein
Which nerve provides cutaneous sensation to the anterior triangle?Transverse cervical (C2-C3)
Where does the anterior jugular vein pierce the investing layer of deep cervical fascia?
Just above the manubrium of the sternum
To what vein does the AJV drain? Where does this occur?
- 1. External jugular vein
- 2. deep to the sternocleidomastoid
Name the group of muscles which attach to the hyoid bone from above and connect it to the cranium.
This group of muscles forms the floor of the mouth and is involved in elevating the hyoid and larynx during speaking and swallowing.
List the suprahyoid muscles (according to table 1 on page 4). Which of these is not truly part of the suprahyoid group?
- 1. Digastric (anterior and posterior belly)
- 2. Stylohyoid
- 3. Mylohyoid
- 4. Hyoglossus (not truly ""suprahyoid"")
Which suprahyoid muscles are innervated by CN VII?
Stylohyoid and posterior belly of digastric
Which suprahyoid muscles are innervated by CN V3? What is another name for the branch of this nerve that is innervating these muscles?
- 1. Mylohyoid and anterior belly of digastric
- 2. Nerve to the mylohyoid
What nerve innervates hyoglossus?
List the strap muscles. What is another name for this group?
- 1. Omohyoid, sternohyoid, sternothyroid, thyrohyoid
- 2. Infrahyoid muscles
What is the main function of the infrahyoid muscles?
Steady the hyoid bone and depress the hyoid and larynx during speaking and swallowing
These two muscles are in the superficial plane of the infrahyoid group.
Superior omohyoid and sternohyoid
These two muscles are in the deep plane of the infrahyoid group.
Thyrohyoid and Sternothyroid (the muscles with ""thyro"" in the name are deep)
One nerve innervates all of the infrahyoid muscles except for one. Which nerve is it and which muscle is the exception?
- Nerve = Ansa cervicalis (C1-C3)
- Exception = Thyrohyoid (innervated by C1)
The CCA arises from ________ on the right and _________ on the left.
- 1. brachiocephalic trunk on the right
- 2. arch of the aorta on the left
At what level does the CCA normally bifurcate?
Level with the superior border of the thyroid cartilage
What two sensory structures are located near the bifurcation of the CCA?
Carotid sinus and carotid body
This sensory structure contains baroreceptors and decreases blood pressure when activated.
The carotid body contains what type of receptor? These receptors respond to what type of signal? Activation leads to what?
- 1. Chemoreceptors
- 2. Respond to decreased oxygen in the blood
- 3. Activation leads to increased heart rate, blood pressure, and respirations
Both sensory structures associated with the CCA are innervated by what?
CN IX, CN X, and sympathetics
What is they number one key identifying feature of the ICA??
The ICA has NO branches in the neck (it banches within the skull)
What are the two terminal branches of the ECA? Where does this division occur?
- 1. Maxillary and Superficial temporal arteries
- 2. behind the neck of the mandible bone."
List the three branches of the ECA located within the neck.
- 1. Superio thyroid
- 2. Lingual
- 3. Facial
Which branch of the ECA is associated with the external laryngeal nerve? Is the artery lateral or medial to the nerve?
- 1. Superior thyroid artery
- 2. Lateral to the nerve
The superior thyroid artery gives off a branch. Name the arterial branch and the nerve it courses with. What membrane do these structures pierce?
- 1. Superior laryngeal branch courses with the internal laryngeal nerve (of CN X)
- 2. They pierce the thyrohyoid membrane
The lingual nerve arises posterior to what structure? It then forms and upward loop which is crossed by what nerve??
- 1. Arises posterior to the greater horn of the hyoid bone
- 2. The loop is crossed by the hypoglossal nerve (CN XII)
Which artery exits the anterior triangle by passing deep to the hyoglossus muscle?
Which artery can originate above or from a common trunk with the lingual artery?
As the facial artery runs upward, it is deep to which muscle?
This artery emerges from behind the submandibular glad and curves around the lower boder of the mandible.
Name the two branches from the posterior aspect of the ECA?
Occipital artery and posterior auricular artery
Which nerve hooks around the occipital artery near its origin?
This artery is usually the first or second branch off the ECA and it ascends medial to the ICA
Ascending pharyngeal artery
Where does the IJV begin?
At the jugular foramen
In the carotid sheath, is the IJV medial or lateral to the CCA?
Which vein enters the anterior triangle and courses superficially over the submandibular gland? What important structure simultaneously courses deep to the gland?
- 1. Facial vein is superficial
- 2. Facial artery is deep"
The facial vein is joined by the ______ vein to form the _______ vein which empties into the IJV?
- 1. anterior branch of the retromandibular
- 2. forms the common facial
This nerve forms a loop of motor nerve fibers derived from ventral rami of C1-C3.
The superior root of Ansa cervicalis is formed by fibers of what cervical spinal nerve? This root courses alongside which Cranial Nerve?
- 1. Spinal nerve C1
- 2. Cranial nerve XIII (hypoglossal)
The superior root of Ansa cervicalis descends on the anterior surface of what structure?
The inferior root of Ansa cervicalis is made up of fiber from which cervical spinal nerves? What is the course of this root?
- 1. Spinal nerves C2-C3
- 2. Descends behind the carotid sheath
The nerve to the thyrohypoid is made up of fibers from what nerve? These fibers (do or do not?) enter the superior root of Ansa?
- 1. C1
- 2. Do not enter superior root of Ansa
Which muscle is innervated by the C1 fibers which are last to leave CN XII ? (Hint: think oral cavity)
When the hypoglossal nerve exits the cranial fossa, it enters what structure in the neck? And courses posterior to what structure?
- 1. Enters cartoid sheath
- 2. Courses posterior to IJV
The hypoglossal nerve hooks around what structure?
What muscle separates the hypoglossal nerve from the lingual artery? Which structure runs deep and which runs superficial to the muscle?
- 1. hyoglossus muscle
- 2. Hypoglossal nerve is superficial; lingual artery is deep
The hypoglossal nerve enters the oral cavity by passing deep to what structure?
The hypoglossal nerve innervates all the ""-glossus" muscles except which?
The vagus nerve (CN X) contains what type of fibers?
Motor, sensory, and preganglionic parasympathetics
The vagus nerve (CN X) exits the cranium via which foramen?
Where can the vagus nerve be found in the neck?
Courses in the carotid sheath between the IJV and the CCA (or ICA superiorly)
The vagus nerve has two ganglia which contain the cell bodies of its sensory neurons. Where are these ganglia located?
- 1. Superior ganglion = within the jugular foramen
- 2. Inferior ganglion = just below the jugular foramen
These branches of the vagus nerve arise from the superior ganglion of the vagus nerve.
Meningeal branches and Auricular branch
These branches arise from the inferior ganglion of the vagus nerve.
Pharyngeal branch, carotid body nerve (can also arise from pharyngeal branch), superior laryngeal nerve.
Which branch of the vagus nerve contains MOTOR fibers? Which muscles does this branch innervate?
- 1. Pharyngeal branch
- 2. All muscles of the palate (except tensor veli palatini) AND all muscles of the pharynx (except stylopharyngeus)
Which nerve (derived from the vagus) provides sensory innervation for the mucous membrane of the larynx AT AND ABOVE the vocal fold?
Where does the internal laryngeal enter the larynx? Along with what other structure?
By piercing the thyrohyoid membrane along with the superior laryngeal artery
Which nerve (derived from the vagus) descends medial to the superior thyroid artery?
This nerve passes deep to the thyroid gland to innervate the cricothyroid muscle.
What provides parasympathetic inneravation to the heart?
Cardiac branches of the vagus nerve
Describe the different courses of the right and left recurrent laryngeal nerves.
Right = arises from the vagus, hooks around the subclavian artery
Left = descends anterior to the aortic arch, then hooks under it and ascends in the neck.
Where can both recurrent laryngeals be found in the neck?
IN the goove between the trachea and esophagus (on either side)
The recurrent laryngeals enter the larynx by passing deep to which structure?
Inferior constrictor muscle
What are the major functions of the recurrent laryngeal nerves?
- 1. Motor to all of the larynx except the cricothyroid
- 2. sensory to the mucous membrane of the larynx AT AND BELOW the vocal folds"
Where can the glossopharyngeal nerve be found in the neck?
In the carotid sheath anterior to the ICA
The spinal accessory nerve crosses anterior to what structure to enter the deep surface of what muscle?
- 1. Anterior to IJV
- 2. Deep surface of sternocleidomastoid
List the three major facial layers of the neck
- 1. Superficial cervical fascia
- 2. Deep cervical facia
- 3. Carotid sheath
What are the layers of the deep cervical fascia?
Investing layer, Pretracheal layer, and Prevertebral layer
What important structure is embedded in the prevertebral fascia?
The Cervical sympathetic trunk
The retropharyngeal space is between what and what?
Between the prevertebral fascia and the buccopharyngeal fascia of the pharynx
The carotid sheath is a condensation of what?
The deep cervical fascia
- What are the three layers of the viscera of the neck?
- 1. Endocrine (thyroid and parathyroid glands)
- 2. Respiratory (larynx and trachea)
- 3. Alimentary (pharynx and esophagus)"
What are the rostral and caudal limits of the thyroid gland in relation to the spinal vertebrae?
Describe the shape of the thyroid gland.
H-shape consisting of two large lateral lobes connected by an isthmus (isthmus may be absent)
True of False: The thyroid gland is larger in females
True; and it enlarges slightly during menstruation and pregnancy
The thyroid gland is covered by what fascia?
This structure develops from an epithelial proliferation of the floor of the pharynx
During development the thyroid gland migrates caudally and remains connected to the tongue via what structure which later becomes solid and disappears?
Which arteries supply the thyroid gland?
Superior and infeior thyroid arteries (both are paired structures)
Which artery which supplies the thyroid gland is accompanied by along part of its course by the external laryngeal nerve?
Superior thyroid artery
Which artery which supplies the thyroid gland is intimately related to the recurrent laryngeal nerve?
Inferior thyroid artery (the nerve may cross anterior or posterior to the artery)
Describe the course of the inferior thyroid artery
Arises from the thyrocervical trunk (of the subclavian artery) and ascends posterior to the carotid sheath to reach the inferior and posterior aspect of the thyroid gland
Name the inconstant, unpaired artery which sometimes supplies the thyroid gland
Thyroid ima artery
When incising the trachea inferior to the isthmus of the thyroid gland, which artery should a surgeon be careful to avoid serious bleeding?
Thyroid ima artery (only in ~10% of the population)
List the three pairs of veins which drain the venous plexus on the surface of the thyroid gland.
Superior thyroid, middle thyroid, and inferior thyroid veins
Which thyroid veins do not follow the course of their corresponding artery?
Inferior thyroid veins
What provides innervation for the thyroid gland?
postganglionic fibers of the cervical sympathetic trunk (this innervation is vasomotor)
What is a goiter? What are some complications of this condition?
- 1. An abnormal enlargement of the thyroid gland
- 2. It may exert pressure on the trachea, esophagus, and recurrent laryngeal nerves with resulting difficulty in breathing, swallowing, and voice changes.
What are some complications secondary to anaplastic carcinoma of the thyroid?
- 1. The tumor can invade/erode adjacent structures including esophagus and tracha
- 2. Erosion of the recurrent laryngeal and cervical sympathetic chain producin changes in the voices and Horner's syndrome
Which nerve must be identified and preserved before ligating the inferior thyroid artery when performing a thyroidectomy?
Recurrent laryngeal nerve
Which nerve must be identified and preserved before ligating the superior thyroid artery when performing a thyroidectomy?
External laryngeal nerve
Why does transection of one recurrent laryngeal nerve result in hoarseness while transection of both recurrent laryngeals causes both hoarseness and breathing difficulties.
The recurrent laryngeal nerves supply all the muscles of the larynx except the cricothyroid muscles. Breathing difficulties are caused because the denervation renders the glottis only partially open.
Transection of one recurrent laryngeal results in the affected vocal cord becoming stuck in the midline-adducted position. If both nerves are cut, both vocal cords fall to the midline and occlude the airway (tracheotomy may become necessary)
How many parathyroid glands are there?
There can be two to six parathyroid glands
Describe the shape and location of parathyroid glands
Small, spherical endocrine glands which lie on the posterior surface of the thyroid gland.
Explain the neurovasculature of the parathyroid glands
- Arteries - usually inferior thyroid (sometimes superior thyroid or both)
- Veins - middle and inferior thyroid
- Nerves - cervical sympathetic trunk
What procedure removes some of the thyroid but leaves parathyroid intact?
Subtotal thyroidectomy (posterior portion of thyroid is preserved)
What is parathormone?
A parathyroid hormone which controls calcium and phosphorus metabolism
What is the clinical result of parathyroid atrophy or inadverten removal?
- Leads to decrease in calcium and an increase in phosphate ions in the blood
- Hypocalcemia leads to tetany
How can hypocalcemia cause death?
Leads to tetany (spasms) of the laryngeal muscles which obstructs respiration
What is the thoracic inlet?
Included in the root of the neck. It is the superior thoracic aperature through which all structures pass between the thorax and neck.
What are the boundaries of the root of the neck?
- Anterior = manubrium sterni
- Posterior = body of the T1
- Lateral = 1st pair of ribs and their costal cartilages
What lung structure extends into the lateral parts of the root of the neck?
Cupola (or apex) of the lung
What is the key landmark of the root of the neck to which every other important structure of the region is related?
- Anterior scalene muscle
- Originates = transverse process C3-C6
- Inserts = scalene tubercle of first rib
- Action = elevates first rib
- Innervation = Ventral rami of C4-C7
Which impotant structures are related to the ANTERIOR side of the anterior scalene?
- 1. Phrenic nerve
- 2. Suprascapular and Transverse Cervical Arteries
- 3. Subclavian and internal jugular veins"
Which impotant structures are related to the POSTERIOR side of the anterior scalene?
- 1. Subclavian artery
- 2. brachial plexus
- 3. apex of the lung and cupola
Which impotant structures are related to the MEDIAL to the anterior scalene?
- 1. Subclavian Artery
- 2. CCA
- 3. Thyrocervical Trunk
- 4. Inferior thyroid
- 5. Vertebral artery
- 6. Vagus nerve"
Which impotant structures are related to the LATERAL to the anterior scalene?
- 1. Subclavian
- 2. Roots of the phrenic nerve unite at the lateral border of muscle at C6
The CCA arises from the brachiocephalic artery on which side of the body?
On the right (from the arch of the aorta on the left)
What are the three branches off of the subclavian artery medial to the anterior scalene muscle?
Vertebral, Internal thoracic, and thyrocervical trunk
What are the three branches off of the thyrocervical trunk?
Suprascapular, Transverse Cervical, and Inferior Thyroid arteries
The ascending cervical artery arises from the arch of what artery? And it ascends on which muscle? To supply which structures?
- 1. inferior thyroid artery
- 2. Anterior scalene muscle
- 3. supplies the prevertebral muscles
The second part of the subclavian is deep to what structure? Name the one branch in this region.
- 1. Deep to the anterior scalene
- 2. Costocerivcal trunk"
True or False: The third portion of the subclavian artery is lateral to the anterior scalene muscle and extends to the outer border of the first rib. It has NO branches.
The anterior jugular veins drain to which vein?
What is the landmark for finding the IJV for catheterization?
The triangle between the sternal and clavicular heds of the sternocleidomastoid (usually on the right because it is wider and straighter).
Which two major nerves enter the thorax anterior to the subclavian artery?
Phrenic and Vagus
Describe the course of the thoracic duct in the neck
- Enters the neck through the thoracic inlet along the left border of the esophagus
- Acends to C7
- At C7 it courses laterally posterior to the carotid sheath
Which cervical vertebrae has no body and no spinous process?
Which arch of C1 contains a groove for the vertebral artery?
How do some of the facets of C1 and C2 differ from those of other vertebrae?
They are flat (others are angled)
The middle set of craniovertebral ligaments consists of three layers deep to what structure? Name the three layers.
- 1. Dura mater in the vertebral canal
- 2. Posterior, Intermediate, Anterior
Name the posterior ligaments of the Middle Set
Tectorial membrane and Posterior Longitudinal Ligament
What are the three parts of the Cruciate Ligament of the Intermediate Ligament of the Middle Set? What is the function of these ligaments?
- 1. Transverse ligament, superior band, and inferior band
- 2. Hold the dens in place"
Name the anterior ligaments of the Middle Set
Apical and Alar ligaments
Name the broad thin band that extends from the posterior margin of foramen magnum to posterior arch of the atlas
Posterior Atlanto-occipital membrane
Why are cervical vertebrae vulnerable to dislocation?
Because they are less tightly interlocked than vertebrae at other levels.
How can cervical IV discs be ruptured without fracture of the vertebrae?
Hyperflexion (e.g. during a head on collision)
What are some clinical components of "whiplash"
Hyperextension of the cerivcal vertebrae and tearing of the anterior longitudinal ligament
What happens if the transverse ligament is ruptured?
The spinal cord can be compressed between the posterior arch of C1 and the dens of C2 = quadriplegia OR the spinal cord can be displaced into the brainstem = death
Which major artery pierces the atlanto-occipital membrane to enter foramen magnum?
List the prevertebral muscles
Longus colli, longus capitis, and scalene (post, middle, ant) muscles
Which prevertebral muscles can be injured in a whiplash incident?
Longus colli and longus capitis
Which cervical nerves are mixed nerves?
dorsal rami of C2-C8
Which cervical nerve gives off the greater occipital nerve? Is is motor or sensory?
- 1. C2 dorsal ramus
- 2. sensory
Which spinal nerves form the cervical plexus?
C1-C4 ventral rami
The roots from which spinal nerves send white rami to the sympathetic trunk? White rami contain what type of fiber?
- 1. T1-T4
- 2. Preganglionic sympathetics
How many cervical ganglia are there?
Why are there no white rami for any of the cervical ganglia?
Because the preganglionic sympathetics for this region travel in the sympathetic trunk
Postganglionic sympathetic fibers from the cervical ganglia provide innervation to what?
C1-C8 dermatomes, the heart, and the head (face and orbit)
Name the three cervical ganglia and the structure with which each is associated.
- 1. Superior ganglion - posterior to the bifurcation of the CCA on the longus coli muscle
- 2. Middle ganglion - near C6 vertebra, assoc with Inf Thy Artery
- 3. Inferior ganglion - anterior to C7 transverse process, assoc with Vertebral Artery
What nerve connects the MCG to the ICG? This nerve is part of what structure?
- 1. Ansa subclavia
- 2. Cervical sympathetic trunk"
Describe the course of Ansa subclavia
Crosses the first part of the subclavian artery (medial to ant. scalene) often between the origins of the vertebral and internal thoracic arteries. It then loops back rostrally posterior to the subclavian to attach to ICG.
Horner's Syndrome result from a lesion in what four major places?
- 1. IML cell column of T1-T4
- 2. T1-T4 ventral roots
- 3. T1-T4 spinal nerves
- 4. Cervical sympathetic trunk or ganglion
- Describe the pharynx
- A fibromuscular funnel-shaped tube situated in front of the vertebral column. It extends (anteriorly) from base of the skull to the inferior border of the cricoid cartilage and (posteriorly) from the base of the skull to the 6th cervical vertebra where it is continuous with the esophagus
The posterior wall of the pharynx is related to what structure posteriorly? �And posterolaterally?
- 1. Prevertebral fascia
- 2. Great vessels and nerves of the carotid sheath"
The pharynx is a common passage for what to systems?
Digestive and respiratory
The pharynx links what structure to the esophagus? And what structure to the inlet of the larynx?
- 1. oral cavity
- 2. posterior apertures of the nasal cavity
How does the pharynx communicate with the middle ear?
Via the auditory tube
The principal muscles of the pharynx insert on what structure?
Is the pharynx a complete tube?
No. It is semicircularin cross-section with an open communication anteriorly with the nasal cavity, oral cavity, and laryngeal cavity
Name the four layers of the pharyngeal wall?
- 1. A mucous membrane
- 2. A submucosa forming the fibrous pharyngobasilar fascia
- 3. A muscular layer
- 4. A loose connective tissue layer forming the buccopharyngeal fascia
This layer of the pharyngeal wall lines the structure
This layer of the pharyngeal wall is attached to the skull and define the limits of the upper portion of the wall.
Submucosa and the fibrous pharyngobasilar fascia
The pharyngeal plexus of nerves lies on this layer of the wall
What separates the buccopharyngeal fascia from the prevertebral fascia?
How many pairs of muscles form the muscular layer of the pharyngeal wall?
Six (3 internal, 3 external)
What three muscles form the external group of the muscular layer of the pharyngeal wall? What nerve innervates these muscles?
- 1. Superior constrictor
- 2. Middle constrictor
- 3. Inferior constrictor
- All innervated by branches of the Vagus (from the pharyngeal plexus)
What structure enters the pharynx in the interval between the anterior and posterior attachments of the superior constrictor? (Bonus: What are the ant and post attachments of this muscle?)
Auditory tube(Anterior attachment: pterygoid hamulus; Posterior attachment: pharyngeal tubercle)
What two structure enters the pharynx in the interval between the superior and middle constrictors?
- 1. Glossopharyngeal nerve
- 2. Stylopharyngeus muscle
What two structure enters the pharynx in the interval between the middle and inferior constrictors?
Internal laryngeal nerve
What structure can be found deep and caudal to the inferior constrictor muscle?
Recurrent laryngeal nerve
Name the three internal group of the muscular layer of the pharynx. Which muscle is NOT innervated by the Vagus nerve? (Bonus: what nerve innervates this muscle?)
- 1. Salpingopharyngeus, palatopharyngeus, stylopharyngeus
- 2. Stylopharyngeus is innervated by glosso
What is the function of the internal group of muscles in the pharynx?
Elevate the pharynx and larynx during swallowing
We divide the pharynx into thee parts based on the cavities is communicates with. Name the parts.
- 1. Nasopharynx
- 2. Oropharynx
- 3. Laryngopharynx
What is another name for the posterior nasal aperatures?
Where does the nasopharynx end?
Pharyngeal isthmus (the opening between the back of the soft palate and the posterior wall of the pharynx)
What three structures abut the posterior wall of the nasopharynx?
- 1. basilar part of the occipital bone
- 2. anterior arch of the Atlas
- 3. body of the Axis
What structure is located at the upper end of the posterior wall of the pharynx in the mucous membrane? What is this structure called when it is enlarged?
- 1. Pharyngeal tonsil
- 2. Adenoids
What pharyngeal structure can obstruct the passage of air from the nasal cavity through the choanae making mouth-breathing necessary?
The one-third of the auditory tube which is related to the middle ear is (osseous or cartilaginous) and the two-thirds related to the pharynx is (osseous or cartilaginous)?
- 1. Osseous
- 2. Cartilaginous
What is the Torus Tubarius?
a hood-like tubal elevation over the pharyngeal orifice of the auditory tube. It is produced by the projection of the base of the cartilaginous part of the auditory tube.
What structure extends inferiorly from the Torus Tubarius? What does it contain?
- 1. Salpingopharyngeal fold
- 2. Salpingopharyngeal muscle
How can infections in the pharynx spread to the middle ear?
- 1. The lining of the middle ear is continuous with the pharyngeal mucosa.
- 2. Otitis media can arise from inflammation of the pharyngeal tonsils because of their close relationship with the auditory tube.
What is the inferior limit of the oropharynx?
The superior border of the epiglottis (at the level of the hyoid bone)
Where are the palatine tonsils?
Within the lateral walls of the oropharynx in the triangular interval between the palatoglossal and palatopharyngeal arches.
What two "arches" containing small "whispy" muscles exist in the oropharynx? Which arch is more anterior? Which arch contains a more substantial muscle? (Bonus: What is special about this muscle compare to other muscles with similar names?)
- 1. Palatoglossal and palatopharyngeal arches contain muscles of the same name (respectively).
- 2.Palatoglossal arch is more anterior
- 3. Palatoglossus muscle is more robust
- (it is the only ""glossus"" muscle innervated by CN X)
What is the most anterior structure of the oropharynx?
What is another name for the laryngopharynx?
What is the relationship between the laryngopharynx and the larynx?
The laryngopharinx lies posterior to the larynx
What are the landmarks for the borders of the laryngopharynx?
Superior border of the epiglottis to the inferior border of the cricoid cartilage (here it narrows and becomes continuous with the esophagus)
What is another name for the opening of the larynx?
What muscles form the posterior and lateral walls of the laryngopharynx externally? And internally
- 1. Middle and inferior constrictors, externally
- 2. Palatopharyngeus and stylopharyngeus, internally
What separates the Piriform recess from the inlet of the larynx?
The aryepiglottic fold
What nerve lies deep to the mucous membrane of the piriform recess? (Bonus: What other structure is associated with this nerve?)
- Internal laryngeal nerve
- (It is associated with the superior laryngeal artery)
What can cause anesthesia of the laryngeal mucous membrane as far inferiorly as the vocal folds?
Foreign bodies entering the pharynx (e.g. chicken bones) can be sharp and pierce the mucous membrane of the Piriform Recess and damage the internal laryngeal nerve
What nerveous structures form the Pharyngeal Plexus?
- 1. Vagus nerve (CN X)
- 2. Glossopharyngeal nerve (CN IX)
- 3. Sympathetic branches from the superior cervical ganglion
What supplies the motor and (most of) the sensory innervation for the pharynx?
The Vagus nerve innervatese all muscles of the pharynx and soft palate EXCEPT which two muscles? (Bonus: What are these muscles innervated by?)
- 1. Stylopharyngeus (CN IX)
- 2. Tensor veli palatini (CN V)
What is bulbar palsy? Why is choking a common symptom? What is the clinical term for difficulty swallowing?
- 1. Degeneration of motor neurons in CN IX and CN X
- 2. Because these nerves innervate the pharynx
- 3. Dysphagia
What supplies the sensory fibers for most of the pharynx? What area is the exception? What is this area innervated by?
- 1. Glossopharyngeal nerve
- 2. Anterior part of the nasopharynx
- 3. CN V3 (maxillary division)
What artery supplies the pharynx? What does this artery branch from?
- 1. Ascending pharyngeal
- 2. External carotid
The pharyngeal plexus of veins drains to two places - name them.
- 1. IJV
- 2. Pterygoid plexus of veins
Where do the lymphatic vessels of the pharynx drain?
Deep cervical lymphnodes (directly or indirectly)
- Describe the larynx
- Rigid-walled tubelike structure about 5cm long (shorter in females), deep to the infrahyoid muscles. Extends from the laryngeal inlet (near the root of the tongue) to the trachea."
What are the boundaries of the laryngeal aditis?
- Superior = epiglottis
- Inferior = arytenoid cartilages
- Lateral = aryepiglottic folds
What organ is responsible for speech (phonation)?
In what three situations can temporary closure of the airway at the larynx occur?
- 1. swallowing
- 2. speech
- 3. just before coughing or sneezing
In what three ways is the airway protected during swallowing?
- 1. sphincter-like action of the muscles at the laryngeal aditis
- 2. displacement of the epiglottis over the aditis
- 3. elevation of the larynx
How many cartilages are joined to form the laryngeal skeleton?
Name the cartilages of the larynx
- Three single: thyroid, cricoid, and epiglottis
- Three paired: arytenoid, corniculate, cuneiform
Which cartilages are composed of elastic cartilage?
Epiglottic, cuneiform, corniculate
These cartilages of the larynx are hyaline and ossify with age.
Thyroid, cricoid, and arytenoid
What is the superior border of the thyroid cartilage? To what structure does it attach?
- 1. Thyrohyoid membrane
- 2. Hyoid bone
What is another name for laryngeal prominence? The prominence is part of what structure?
- 1. Adam's apple
- 2. Thyroid cartilage
The Thyroid Notch is (superior or inferior) to the laryngeal prominence?
Why is the laryngeal prominence larger in males than in females post-puberty?
Because the angle at which the thyroid laminae meet is more acute in males and the anteroposterior diameter of the laminae is greater.
The oblique line is located where on the laminae of the thyroid? And it provides attachment for what structures?
- 1. the lateral surface of each
- 2. Inferior constrictor, sternothyroid, and thyrohyoid
What is special about the articulation of the thyroid cartilage with the cricoid cartilage?
The inferior horns of the thyroid cartilage articulate with the cricoid at special facets which allow the thyroid cartilage to tilt/glide anteriorly or posteriorly
Which laryngeal cartilage is the only complete ring found in the respiratory system?
The cricoid cartilage articulates with what structures?
Thyroid cartilage (on lateral surface of cricoid) and arytenoid cartilage (on superior border of cricoid)
What are the two processes of the arytenoid cartilages?
- Vocal process - anterior projection which attaches to vocal ligament
- Muscular process - lateral projection which is the point of insertion for the posterior and lateral cricoarytenoid muscles AND the thyroarytenoid muscle"
Which laryngeal cartilages are located in the posterior part of the aryepiglottic folds?
Corniculate and cuneiform
Describe the two ligaments which attach to the epiglottic cartilage
- Thyroepiglottic ligament - attached to the tapered inferior surface of epiglottis
- Hyoepiglottic ligament - attaches the anterior surface of the epiglottis to the hyoid bone"
What are the glossoepiglottic folds? What are the valleculae?
- 1. Reflections of the mucous membrane covering epiglottis onto the root and sides of the tongue (one median, two lateral folds exist)
- 2. The depressions in between the median and lateral folds
What prevents the epiglottis from falling down over the entrance to the larynx during swallowing?
The hyoepiglottic ligament
What are the adverse affect caused by surgical removal of the epiglottis?
Trick question - NONE
The larynx is raised during swallowing forcing the edges of the aryepiglottic folds against the epiglottis (which is then forced against the base of the tongue)
Name the two pairs of synovial joint in the larynx?
Cricothyroid joints and Cricoarytenoid joints
Which joints are responsible for changes in length of the vocal folds, and slackening/tightening the vocal ligaments?
Which joints allow the arytenoid cartilages to slide and rotate(approximating, tensing, and relaxing the vocal folds)?
What structure serves to suspend the larynx from the hyoid bone?
The thyrohyoid membrane thickens medially to form the ________
The inferior margin of this membrane is free and forms the vestibular ligament
This is an elastic membrane which attaches inferiorly to the arch of the cricoid cartilage
What is another name for vestibular folds?
False vocal cords
What is the space between the vestibular folds called?
What are the thickenings of the superior border of the conus elasticus called?
What muscles are located lateral to the vocal ligaments?
Vocalis and thyroarytenoid muscles
The space between the vocal folds (true vocal cords) is called ...?
The narrowest part of the laryngeal cavity (the space between the apposed vocal folds and the arytenoid cartilages) is called...?
True or false: On laryngoscopic exam, one can only observe the vestibular folds?
False: both sets of folds are visible by laryngoscopic exam
What is the usual location for aspirated food to become lodge causing the victim to choke?
Rima glottidis (this is why the Heimlich maneuver is helpful in this situation)
What are the two categories of laryngeal muscles? What is the major distinction?
- 1. Intrinsic and extrinsic
- 2. Intrinsic move PARTS of the larynx; extrinsic move the WHOLE larynx
What three extrinsic laryngeal muscles ELEVATE the larynx?
- 1. thyrohyoid
- 2. stylopharyngeus
- 3. palatopharyngeus
What three extrinsic laryngeal muscles DEPRESS the larynx?
- 1. omohyoid
- 2. sternohyoid
- 3. sternothyroid
Why can elevation of the larynx occur by the actions of the suprahyoid msucles?
Because the larynx and the hyoid bone are connected via the thyrohyoid membrane
What nerve supplies most of the intrinsic muscles of the larynx? Which muscle is the once exception? What nerve supplies this muscle? (Bonus: what other structure is associated with this nerve?)
- 1. Recurrent laryngeal (inferior laryngeal)
- 2. Cricothyroid
- 3. External laryngeal
- (Bonus: Superior thyroid artery)
What structure forms the dividing line for sensory innervation of the larynx? What innervates ABOVE, AT, and BELOW this structure?
- 1. Vocal folds
- 2. ABOVE = internal laryngeal (branch of superior laryngeal of CN X)
- 3. AT = internal AND inferior laryngeal nerves (both of CN X)
- 4. BELOW = inferior laryngeal only
Why is explosive coughing induced which a foreign body contact the mucosa of the larynx superior to the vocal ligaments?
Because this region is extremely sensitive
Where does the recurrent laryngeal nerve ascend? When does it change names to inferior laryngeal nerve?
- 1. Between the trachea and the esophagus
- 2. When is courses deep to the inferior border of the inferior constrictor muscle
The external laryngeal nerve ends on what structure?
Which arteries supply the larynx? They branch off of which arteries?
- 1. Superior and inferior laryngeal arteries
- 2. Superior and inferior thyroid arteries (respectively)
True or false: The venous drainage runs parallel (and has corresponding names) to the arterial supply of the larynx?
True: superior and inferior laryngeal veins
Where to the lymphatic vessels of the larynx drain?
To the superior and inferior cervical lymph nodes
From superior to inferior list the cavities of the interior of the larynx
- Inlet = communicates with laryngopharynx
- Vestibule = lateral walls are the quadrangular membranes
- Ventricle = between false and true cords; smallest cavity
- Infraglottic cavity = most inferior, related to trachea
True or False: There is no coelomin the head and neck, so mesoderm is classified only as paraxial (somitomere/somites) or lateral plate?
How many pharyngeal arches are there? How are they numbered?
- 1. Five
- 2. 1,2,3,4 and 6 (there is no recognized arch 5)
What are the contents of each pharyngeal arch?
- 1. skeletal element (derived from neural crest or mesoderm)
- 2. muscular element (derived from mesoderm)
- 3. a cranial nerve
- 4. an aortic arch
What type of gene is responsible for regulating cranio-caudal development of the pharyngeal arches?
HOX (homeobox) genes
Which pharyngeal cleft is the only one to persist in the adult? What adult structure does it give rise to?
- 1. First arch
- 2. Gives rise to acoustic meatus
Why is Matt Byrne so delicious? OR What does MMATT stand for?? Which cranial nerve should you be thinking about right now?
- Because he reminds us of the mnemonic for the muscles derived from Arch 1
- MMATT (mastication muscles, mylohyoid, anterior belly of the digastric, tympani, tensor veli palatini)
- CN V
What does FESSP stand for? Which cranial nerve should you be thinking about right now?
- Muscle derivatives of Arch 2 (facial expression muscles, stapedius, stylohyoid, posterior belly of digastric)
- CN VII
Which cranial nerve is associated with each pharyngeal arch (Arches 1,2,3,4,6)?
- Arch 1 = CN V
- Arch 2 = CN VII
- Arch 3 = CN IX
- Arch 4 = CN X, superior laryngeal branch (Think 10-4 good buddy)
- Arch 6 = CN X, recurrent laryngeal
What is a cervical fistula? From what embryological structure does such a complication arise?
- 1. A patent connection between the skin of the neck to the area of the palatine tonsil
- 2. Cervical sinus which is normally closed over and obliterated - can persist as a cyst or opening to the skin at the anterior border of the SCM.
How many pharyngeal pouches are there?
What are the derivatives of each pharyngeal pouch?
- Pouch 1 = middle ear and auditory tube
- Pouch 2 = Tonsillar crypts
- Pouch 3 = Inferior parathyroids and thymus
- Pouch 4 = Superior parathyroids
- Pouch 5 = C cells (orginally from neural crest) of thyroid gland
What is the embryological reason behind the innervation of the tongue? (Anterior 2/3 receives sensory innervation from CN V3, Posterior 1/3 receives sensory innervation from CN IX)
Because the POSTERIOR 1/3 of the tongue is derived from the copula (tissue from Arches 2,3,4) and the ANTERIOR 2/3 is derived from the tuberculum impar (lateral swellings related to Arch 1)
What structure represents the thyroid's original location in embryological development?
The Foramen Cecum of the tongue (a depression in the tongue tissue)
Why can cysts or ectopic thyroid tissue be found anywhere between the foramen cecum of the tongue and the nomal location of the thyroid?
Because the thyroid decsends along this pathway during development
What causes a "hare lip"?
Failure of a maxillary prominence to fuse with its adjacent medial nasal prominence
What causes a cleft face?
Failure of a maxillary prominence to fuse with it�s the lateral AND medial nasal prominences
What is Treacher-Collins syndrome?
A developmental anomaly characterized by underdeveloped zygomatic and mandibular bones in combination with downslanting palebral fissures and malformed external ears
What is the Pierre-Robin sequence?
Similar to Treacher-Collins - affects the first pharyngeal arch structures (MMATT). Usually presents with small jaw, cleft palate, and posteriorly displaced tongue
During development, the tongue obtains a lower position with forward growth of the mandible and the maxillary prominences swing up and meet each other, the intermaxillary segment, AND the nasal septum. If any of this fails to occur, what defect arises?
What is the posterior boundary of the oral cavity?
The palatoglossal arch (here it becomes continuous with the oropharynx)
What are the three functions of the oral cavity?
- 1. Ingestion and mastication of food
- 2. Phonation
- 3. Ventilation
What are the two subdivisions of the oral cavity? Describe each.
- 1. Vesitbule - narrow space between lips/cheeks and gums/teeth
- 2. Oral Cavity Proper - teeth/gums => hard/soft palate => ant. 2/3 of the tongue => palatoglossal arches
How many permanent teeth do you have?
32 (4 incisors, 2 canine, 4 premolar, 6 moalars each in upper and lower)
What is the incisive papilla?
Located behind the maxillary central incisors - it is a mucosa covering the nasopalatine nerves as they emerge from the incisive canal.
What structures transmit the greater and lesser palatine nerves and vessels? Where are these structures located?
- 1. The greater and lesser palatine foramina
- 2. posterolateral border of the hard palate
What are the Pillars of the Fauces?
- Two folds of mucosa that extend from the lateral margins of the soft palate:
- 1. Palatoglossal fold
- 2. Palatopharyngeal fold
Which Pillar of Fauces is NOT located in the Oral Cavity Proper?
The Palatopharyngeal Fold - it is located in the oropharynx
Name the five muscles associated with the soft palate.
- 1. Tensor veli palatini
- 2. Levator veli palatini
- 3. Palatopharyngeus
- 4. Palatoglossus
- 5. Musculus Uvulae
All the muscles of the soft palate are innervated by CN X via the pharyngeal plexus EXCEPT which? What nerve innervates this muscle?
- 1. Tensor veli palatini
- 2.CN V3
To what three structures is the tongue connected (and connected by what)?
- 1. Palate by Palatoglossal Arch
- 2. Pharynx by Superior Constrictor Muscle
- 3. Epiglottis by Glossoepiglottic Folds
The anterior 2/3 of the tongue is known as the _______ and the posterior 1/3 is known as the ________. What landmark lies in between?
- 1. oral part (body)
- 2. pharyngeal part (root)
- 3. Sulcus terminalis
What structures lies anterior to the sulcus terminalis and contain a large number of taste buds?
What structure is located at the apex of the sulcus terminalis? It is a remnant of what embryonic structure?
- 1. Foramen cecum
- 2. Thyroglossal duct
What is the midline of the tongue called?
What is the lymphoid tissue located in the root of the tongue called?
True or False: Even though the mucous membrane of the root of the tongue contains no papillae, taste buds are still present in this region?
What is the Frenulum of the tongue?
a midline fold of mucous membrane which connects the tongue to the floor of the mouth
If an infant suffers from ankyloglossia, what is wrong?
The frenulum of the tongue extends further than normal (almost to the tip of the tongue) and interferes with protrusion of the tongue
What vein is located on either side of the frenulum of the tongue?
Deep lingual vein
How is the location of the deep lingual vein used for quick absorption of certain drugs?
If dissolvable drugs are placed under the tongue, they can enter the deep lingual vein in less than one minute because it is thinly covered by mucosa.
The intrisic msucles of the tongue are innervated by what nerve? And what is their function?
- 1. Hypoglossal (CN XII)
- 2. Change the shape of the tongue
Name the four pairs of extrinsic muscles of the tongue.
- 1. Styloglossus
- 2. Hyoglossus
- 3. Genioglossus
- 4. Palatoglossus
All of the extrinsic muscles of the tongue are innervated by CN XII EXCEPT which muscle? What nerve innervates this muscle?
- 1. Palatoglossus
- 2. CN X (vagus)
What nerves supply the sensory innervation of the tongue (general sensation and taste)?
CN V, VII, IX, and X
Which nerves give general sensation to the following portions of the tongue:
- Oral Part
- Pharyngeal Part
- Epiglottic Region
- 1. Oral = Lingual Nerve (CN V)
- 2. Pharyngeal = Glossopharyngeal (CN IX)
- 3. Epiglottic = Superior Laryngeal (CN X internal branch)
Which nerves give TASTE sensation to the following portions of the tongue: Oral Part, Pharyngeal Part, Epiglottic Region
- 1. Oral = Chorda Tympani (CN VII)
- 2. Pharyngeal = Glossopharyngeal (CN IX)
- 3. Epiglottic = Superior Laryngeal (CN X internal branch)
Which artery supplies the tongue? It is a branch off of ______ and courses deep to _______ muscle.
- 1. Lingual artery
- 2. ECA
- 3. Hyoglossus muscle
Which veins of the tongue course with the lingual arteries? Which veins accompany the hypoglossal nerve?
- 1. Dorsal veins with lingual artery
- 2. Deep veins with hypoglossal nerve
True or false: The tongue is a frequent site of cancer thus it's important to know that the lymph tissue drains to the deep cervical lymph nodes
What structure forms a muscular diaphragm for the floor of the mouth?
What muscles are found above the mylohyoid medially? And what muscles are found above the mylohyoid laterally?
- 1. Geniohyoid (and even high is Genioglossus)
- 2. Hyoglossus
What is the sublingual caruncle?
a papilla with an opening for the submandibular duct (located on either side of the frenulum of the tongue)
What is the Plica sublingualis?
The sublingual fold - extends posteriorly and laterally from the caruncle and contains many openings for the ducts of the sublingual gland
What three major glands secrete into the mouth (list largest to smallest)?
- 1. Parotid glands
- 2. Submandibular glands
- 3. Sublingual glands
Which glands of the mouth are found on the mylohyoid muscle between the mandible and the genioglossus muscles?
Which glands of the mouth have ducts which open on the sublingual caruncle?
Salivary glands are innervated by parasympathetic ganglia related to which cranial nerves?
CN VII and CN IX
Which nerve "taxis" taste fibers from the anterior 2/3 of the tongue to the chorda tympani (CN VII) ?
The lingual nerve (of CN V3) has an important relationship with what structure?
- Duct of the submandibular gland
- (The nerve begins lateral to the duct and passes inferior to it and ascends to the tongue - now medial to the duct)
Where is the submandibular ganglion found?
Suspended from the lingual nerve adjacent to the deep part of the submandibular glad and on the hyoglossus muscle
The nerve to the mylohyoid is an indirect branch of what cranial nerve? It innervates the mylohyoid and what other muscle?
- 1. CN V3
- 2. anterior digastrics
The hypoglossal nerve courses deep to ______ muscle on the lateral surface of ______ muscle which it innervates.
- 1. mylohyoid
- 2. hyoglossus
Damage to what nerve causes lower motor neuron lesion leading to paralyisis and atrophy of the ipsilateral side fo the tongue's musculature? What is the clinical sign of this damage?
- 1. Damage to hyopglossal nerve
- 2. When the patient sticks his or her tongue out, it will deviate to the lesioned side
Fibers from which cervical spinal nerve hitchike with the hypoglossal nerve? The first fibers to jump off make up what structure? The last fibers to jump off course where and innervate what muscle?
- 1. C1 Fibers
- 2. Superior root of Ansa cervicalis
- 3. Course anterior to hyoglossus muscle and innervate the geniohyoid muscle
What are tonsilar crypts?
Slit-like pits on the exposed surface of the palatine tonsil
The tonsillar bed (for the palatine tonsil) is bordered laterally by a firm capsule which is continuous with what fascia and what muscle?
- 1. pharyngobasilar fascia
- 2. superior constrictor muscle
The lateral surface of the tonsilar bed is in close association with five important structures. Name them.
- 1. facial artery
- 2. facial vein
- 3. internal carotid artery
- 4. superior constrictor muscle
- 5. Glosspharyngeal nerve
Considering the structures that are closely related to the tonsillar bed, edema following a tonsillectomy can compress which nerve and lead to a temporary loss of taste?
Glossopharyngeal (CN IX)
The tonsillar artery is a branch off which major artery?
The tonsillar plexus (innervation for the palatine tonsil) is formed by branches from which two cranial nerves?
CN IX (glossopharyngeal) and CN X (vagus)
The lymphatics of the palatine tonsil drain to what lymph node?