Coronal & Saggital Suture Junction
episodes of intense pain in the face, originating from the trigeminal nerve.
greater occipital nerve
spinal nerve, dorsal ramus of cervical spinal nerve 2
Head & Neck Dermatomal
- C1 has no cutaneous branch to the head and neck.
- V1, V2, and V3 branches to the face.
- C2, C3, and C4 fibers to the head
External Carotid Artery
- 1. ascending pharyngeal a.
- 2. superior thyroid a.
- 3. lingual artery
- 4. facial artery (crosses the body of the mandible)
- a. inferior labial a. (related to the lower lip)
- b. superior labial a. (related to the upper lip)
- c. angular a. (related to the angle of the nose & eye – terminal br of facial a.)
- 5. occipital artery
- 6. maxillary artery (courses deep to neck of mandible; a terminal br of the ECA)
- 7. superficial temporal a. (a terminal br of the ECA)
- a. transverse facial a. (courses anteriorly, superior to parotid duct)
How is the retromandibular vein formed? Within which gland does this vein run?
- Maxillary Vein & Superficial Temporal Vein
- terminates by forming an anterior division (which joins the facial v. to form the common facial vein draining into the internal jugular v)
- and a posterior division which drains into the external jugular v.
- Parotid Gland
travels within the parotid gland, crosses the sternocleidomastoid superficially and drains into the subclavian vein.
internal jugular vein
- begins at the jugular foramen (as it connects with the sigmoid sinus)
- descends in the neck within the carotid sheath and terminates by joining with the subclavian vein to form the brachiocephalic vein.
- It drains blood from the brain, superficial face, and neck.
- Its tributaries include: common facial v., lingual v., superior & middle thyroid vs., pharyngeal v
- originates by the union of the supra-orbital and supratrochlear veins.
- Its first part is called the angular vein which begins at the angle of the eye and nose.
- Its tributaries include: supraorbital, supratrochlear, external nasal, deep facial, superior & inferior labial, submental & submandibular veins.
- The deep facial vein has a connection to the pterygoid venous plexus.
- There are also connections with the superior & inferior ophthalmic veins in the orbit which connect to the cavernous sinus inside the cranium.
- These “connections” are important in understanding the pathways for the spread of infection.
- The facial vein drains into the common facial vein, which then drains into the internal jugular vein
What is the significance of the danger area of the face?
- facial vein has connections with the superior & inferior ophthalmic vs and pterygoid venous plexus (via the deep facial vein) which drain into the cavernous sinus on the inside of the cranium.
- By such connections, infections on the face can spread into the cranial cavity.
What do emissary veins do? What is their clinical significance?
- Emissary veins pass through the bones of the calvaria (skull cap) to drain blood from the scalp into the intra-cranial venous sinuses.
- Clinical Note: This is another potential pathway for the spread of infection from the superficial head region to the intracranial region (including the brain).
What is the name of the fascial capsule that surrounds the parotid gland?
What are the mumps?
- Mumps is a viral infection that causes inflammation and swelling of the parotid gland.
- Severe pain occurs because swelling is limited by the parotid sheath.
- Pain produced by mumps may be confused with a toothache…
What is the course of the parotid duct and where does it end?
(Stensen’s Duct) crosses the masseter, pierces the buccinator, & opens up into the oral cavity opposite the upper second molar (upper M2).
What groups of nodes are included in the pericervical collar nodes?
parotid, buccal, submental, submandibular, occipital, and mastoid groups of nodes.
Which groups of nodes are included in the superficial cervical nodes?
external jugular nodes & anterior jugular nodes & accessory nodes
Describe the general pattern of lymph flow in the head and neck?
- Lymph drains into the pericervical collar of nodes & superficial cervical node groups.
- From these groups, it then drains into the deep cervical chains (of nodes) and then into the venous system via the thoracic duct (left side) and right lymphatic duct (right side).
- These two ducts are located at the junctions of the internal jugular vein and subclavian veins.
Which lobe of the brain occupies the cranial fossae?
Which bones form cranial fossae?
- anterior - frontal, sphenoid
- middle- sphenoid, temporal
- posterior - occipital, temporal
medial & lateral pterygoid plates
are a feature of the sphenoid bone. They serve as an attachment sites for some muscles of mastication that we will learn (e.g., the medial & lateral pterygoid muscles).
What is the location of the straight sinus?
- located in the intersection of the falx cerebri and tentorium cerebelli.
- interconnects with the inferior sagittal sinus and the confluens of sinuses
The confluens of sinuses corresponds to which bony point? Which sinuses meet at the confluens of sinuses?
- meeting point of superior sagittal sinus, straight sinus, transverse sinuses, and occipital sinus (not depicted in our slides).
- corresponds with the internal occipital protuberance.
- located on the basilar surface of the occipital bone.
- interconnects the cavernous sinus, inferior petrosal sinus, and internal vertebral venous plexus (inferiorly through the foramen magnum
What are the interconnections of the cavernous sinus?
- located on the lateral sides of the sella turcica of the body of the sphenoid.
- interconnect with the ophthalmic veins (through the superior orbital fissure) and with the basilar, superior & inferior petrosal sinuses, and the pterygoid venous plexus (not depicted).
Where does the sigmoid sinus drain? What are its interconnections?
- sigmoid sinus is located at the junction of the petrous part of the temporal bone and occipital bone.
- drains into the internal jugular vein and has connections to the transverse, superior petrosal and inferior petrosal sinuses.
Which two major arteries will come together to form the components of the Circle of Willis? What are the actual arteries that comprise the Circle of Willis?
- Circle of Willis from anterior to posterior consists of the:
- anterior communicating
- anterior cerebral
- internal carotid
- posterior communicating
- posterior cerebral arteries.
- internal carotid artery terminates by forming the middle and anterior cerebral arteries.
- vertebral arteries form the basilar artery which then ends by forming the posterior cerebral arteries
The strap muscles are enveloped in what kind of fascia?
- investing fascia is the outermost layer of deep cervical fascia.
- It “invests” or surrounds more superficial muscles like trapezius, the SCM, and the strap muscles of the neck.
What is the general function of the thyroid gland & what are its major parts? Which lobe is often variable (may or may not be present)?
- consists of two lobes: a right and left lobe interconnected by an isthmus.
- Variation: Sometimes a pyramidal lobe is present. Sometimes the isthmus is absent.
What arteries supply the thyroid gland? What veins drain the thyroid gland?
- superior thyroid-external carotid
- inferior thyroid-thyrocervical trunk (subclavian)
- superior & middle thyroid veins->internal jugular
- inferior thyrod vein-brachiocephalic vein
What are the 3 fascias of neck?
investing, prevertebral, pretracheal
What is the general function and location of the parathyroid glands? How many are there?
- secrete parathormone (PTH), a hormone involved in the regulation of blood calcium ion and phosphate ion concentration.
- lie on the posterior surface of each thyroid lobe. There are usually two glands on each side but the number can vary from 2 to 6.
Describe the relationships of the thyroid cartilage, cricothyroid membrane, cricoid cartilage and thyroid gland to each other.
- isthmus of the thyroid gland is inferior to the cricoid cartilage.
- The cricoid cartilage is inferior to the crico-thyroid membrane and thyroid cartilage.
What is the relationship of the hypoglossal nerve (CN XII) to the posterior belly of the digastric muscle?
- hypoglossal is related to the inferior border of the posterior belly of the digastric.
- Fibers from C1 hitchhike along the hypoglossal nerve then leave it to innervate the thyrohyoid and geniohyoid muscle
What is the ansa cervicalis? It is a component of which plexus? The fibers which comprise it come from which spinal cord levels? Which fibers contribute to its superior root? Which contribute to its inferior root?
- ansa cervicalis is a loop-like nerve structure formed by ventral rami fibers from C1-C3
- It is embedded in the carotid sheath.
- It has an inferior (C2-3) and superior root (C1).
- The ansa cervicalis supplies all the strap muscles (sternohyoid, sternothyroid, and omohyoid) except the thyrohyoid (C1).
- It is part of the cervical plexus
21. What are the 5 components of the cervical plexus?
- 1. Cutaneous branches (post. triangle)
- 2. Ansa cervicalis (to strap muscles)
- 3. Phrenic nerve (to diaphragm)
- 4. Contributions to the Accessory Nerve
- 5. Branches to Prevertebral Muscles
What is the carotid sinus? What is the carotid body? Which nerves innervate these structures (and what kind of fibers are involved)?
- carotid sinus is a baroreceptor that monitors changes in arterial blood pressure, innervated mainly by VA fibers of CN IX.
- carotid body is a chemoreceptor that monitors blood O2 and CO2 levels, innervated mainly by VA fibers of CN X.
Which muscles form the floor of the submandibular triangle?
mylohyoid and hyoglossus muscles form the floor of the submandibular triangle
The hypoglossal nerve passes between which two muscles as it enters into the oral cavity?
the hypoglossal nerve (CN XII) passes from the carotid triangle into the submandibular triangle and comes to lie between the hyoglossus and mylohyoid muscles as it enters the oral cavity. It will innervate tongue muscles.
What is the relationship of the stylohyoid muscle to the posterior belly of the digastric?
- the stylohyoid muscle is related superiorly to the posterior belly of the digastric muscle.
- The tendon of the stylohyoid splits as it attaches to the hyoid bone to allow the tendon of the posterior belly of the digastric to pass through.
Which bones form the roof of the orbit?
- sphenoid (lesser wing)
- frontal bone(orbital plate)
Which bones form the floor of the orbit?
Which bones form the medial wall of the orbit?
ethmoid, lacrimal, maxilla, palatine
Which bones form the lateral wall of the orbit?
greater wing sphenoid, zygomatic
What feature of the orbit is at its apex?
What forms the base of the orbit?
orbital margin, zygomatic, frontal, maxilla
What is the function of the tarsal glands?
produce oil that prevents eyelids sticking together
Describe the course that tears take from the eye to the nasal cavity.
Lacrimal gland → lacrimal ducts → superior & inferior fornix → lacrimal puncta → lacrimal canaliculi → lacrimal sac → nasolacrimal duct → nasal cavity (inferior meatus).
Which 4 nerves provide sensory innervation for the region of the concha?
- sensory innervation to the outer ear is mostly from V3 (auriculotemporal n.) and the cervical plexus (great auricular nerve).
- The region of the concha also receives sensory innervation (SA) from CN VII, and X.
What is the name of the passage way that leads from the auricle to the tympanic membrane?
external acoustic meatus
When the ossicles move, what happens inside the cochlea (of the inner ear)?
fluid current changes in the cochlea which cause specialized hair cells (in the Spiral Organ of Corti) to move and trigger nerve impulses to the brain (via CN VIII) which is interpreted as sound.
What are the functional components of the chorda tympani? And what is its origin (it is a branch of which nerve)?
- branch of CN VII.
- brings taste fibers to the anterior 2/3rds of the tongue
- VE- para/pre fibers to the sub-mandibular ganglion via the lingual nerve (a branch of V3)
The oval window accommodates which bony ossicle?
What is the function of the round window?
- round window on the medial wall.
- membrane of the round window responds to the fluid current changes produced by the footplate of the stapes in the oval window.
What two structures are related to the anterior wall?
internal carotid artery and the opening of the auditory tube
The auditory (Eustachian tube) tube connects which two spaces?
middle ear cavity with the nasopharynx
What is the function of the stapedius muscle? What nerve innervates it?
innervated by CN VII (branchial motor fibers) and acts to dampen the vibration of the stapes, originates from pyramidal eminence
What is the tegman tympani?
thin layer of bone, the tegmen tympani, which covers the middle ear cavity. It helps form part of the floor of the middle cranial fossa.
What venous structure is related to the floor of the middle ear cavity?
internal jugular vein
Within which bone is the cochlear and vestibular labyr (semicircular canal system) located?
To what vertebral level does the pharynx correspond?
extends from the base of the skull to the C6 vertebral level
What is the relationship between the three parts of the pharynx and the epiglottis and the soft palate?
they are the borders
What does a retropharyngeal abscess produce?
difficulty in swallowing and speaking
What are the six general characteristics of the pharyngeal constrictor group of muscles?
- 1- They attach anteriorly to bones and ligaments related to the oral and nasal cavities and to the larynx (depicted in the next slide).
- 2- Posteriorly the paired muscles are joined by the pharyngeal raphe (see this figure).
- 3- They overlap each other.
- 4- They constrict the pharyngeal cavity. They contract voluntarily.
- 5- In swallowing they contract sequentially.
- 6- Their motor innervation is by branchial motor fibers of XI coursing with vagus (XI via X).
Name the specific attachment sites for each one of the pharyngeal constrictor muscles.
- Superior constrictor to the pterygomandibular raphe
- Middle constrictor to the hyoid bone and the stylohyoid ligament
- Inferior constrictor to the thyroid and cricoid cartilages
There are gaps between the pharyngeal constrictor muscles. What specific structures pass through each one of the gaps?
- S-M Stylopharyngeus m., glossopharyngeal n., and stylohyoid ligament
- M-I Internal laryngeal nerve and superior laryngeal artery and vein
- under I Recurrent laryngeal nerve and inferior laryngeal artery
What are the names of the longitudinal muscles of the pharynx? What are their proximal and distal attachments (you are required to know the distal attachment in very general terms – name one structure where they all attach).
- Stylopharyngeus (styloid process),
- Palatopharyngeal (soft palate),
- Salpingopharyngeus (auditory tube- “salpinx” in Greek means “tube”).
What is the general function of the longitudinal muscles of the pharynx?
elevation of the pharyngeal wall
The upper part of the pharynx is supplied (blood) by three main arteries/groups of arteries. Name them and their origin.
- Ascending pharyngeal a.
- Branches of facial a.
- Branches of lingual a.
The lower part of the pharynx is supplied (blood) by a group of arteries. Name this group of arteries and their origin.
pharyngeal branches from thyrocervical trunk
The pharyngeal plexus has four main components. Name them and specify the type of fibers included in each component as well as the destination for each.
Describe the location of the torus tubarius relative to the opening of the auditory tube.
bulge on the pharyngeal wall formed by the rim of the auditory tube opening
Describe the location of the salpingopharyngeal fold relative to the opening of the auditory tube.
mucosal elevations and folds post. to the opening of the tube
Describe the location of the pharyngeal recess relative to the salpingopharyngeal fold.
deep area posterior to the torus tubarius and the salpingopharyngeal fold
Describe the relationships of the laryngopharynx. To what vertebral level does it correspond?
laryngopharynx is at the C4-C6 level
What is the piriform recess? What important structures lie deep to it? Describe a clinical situation (related to the pharyngeal recess) where damage to these structures could result.
- chicken bone pierce the mucous membrane and injure the internal laryngeal nerve.
- This may result in anesthesia of the laryngeal mucous membrane as far inferiorly as the vocal cords.
Name the four arteries that supply the nasal septum. What is the origin of each?
- The septal branch of the anterior ethmoidal a. and the septal branch of the posterior ethmoidal a. are branches of the ophthalmic a.
- The terminal part of the greater palatine a. and the septal branch of the sphenopalatine a. are branches of the maxillary a.
Name the nervous structures that are found in the nasal septum. What is the function of each type of fiber found in the nasal septum?
- olfactory nerve for olfaction;
- Branches of V1 and V2 for sensation;
- VE-Para/post fibers from the pterygo-palatine ganglion for secretomotor innervation of mucous glands.
- Symp/post fibers for regulation of blood flow
What structures are found in the nasal wall? Which of them are part of the ethmoid bone?
middle and superior concha
name the four sinuses and three characteristics they share. Specify the names of the three parts of the “ethmoid sinus”.
- open into the nasal cavities,
- They are all innervated by the trigeminal nerve,
- They are all lined by respiratory mucosa which secretes mucus
How could the removal of a maxillary molar tooth result in a complication related to a paranasal sinus?.
Define sinusitis and pansinusitis.
- inflammation and swelling of the mucosa in the sinuses (sinusitis)
- several sinuses are inflamed (pansinusitis)
Why is inflammation of the mucosa of the maxillary sinus often accompanied by the sensation of toothache?
Because the superior alveolar nerves (branches of V2) supply both the maxillary teeth and the mucous membrane of the maxillary sinus, inflammation of the mucosa of the sinus is often accompanied by the sensation of toothache.
The pterygopalatine fossa communicates with the middle cranial fossa via which foramina?
Rotundum and pterygoid canal
The pterygopalatine fossa communicates with the oral cavity via which canal?
The pterygopalatine fossa communicates with the infratemporal fossa via which fissure?
pterygomaxillary fissure (which constitutes the lateral wall of the pterygo-palatine fossa).
Which main artery courses through the pterygopalatine fossa? How does it terminate? Which branches does it give rise to in the fossa?
- posterior superior alveolar a.,
- infraorbital a.,
- descending palatine a.,
- artery of the pterygoid canal
- pharyngeal a.
- sphenopalatine a
How many branches does the pterygopalatine ganglion have?
- (1) orbital brs,
- (2) posterior superior nasal ns. (lateral &medial groups),
- (3) greater palatine n.,
- (4) lesser palatine n.,
- (5) pharyngeal br.,
- (6) fibers to the lacrimal Gland
Which nerves form the superior dental plexus?
anterior, middle, and posterior superior alveolar nerves interconnect and form the superior dental plexus
What is the nervus intermedius?
Part of VII consists of VE-para/pre fibers, SS (taste), and SA fibers. (no BM)
What muscles are innervated by the fibers of the motor root of CN VII? (be complete)
the muscles of facial expression, stapedius m. (in the middle ear cavity), posterior belly of the diagstric; & stylohyoid m.
Which nerve and artery course through the mandibular notch?
masseteric a. accompanies the masseteric n. through the mandibular notch to the deep surface of the masseter
Which muscle attaches to the coronoid process of the mandible?
Which muscle attaches to the pterygoid fovea of the neck of the mandible?
Lateral pterygoid (medial attaches to angle and ramus)
Which muscle of mastication attaches to the medial surface of the mandibular angle?
How many branches of the V3 Division are there (as we have numbered them)?
- Trunk Branches:
- 1. meningeal br. (not depicted)
- 2. m. pterygoid n.
- Anterior Division Branches:
- 3. masseteric n.
- 4. deep temporal ns.
- 5. lateral pterygoid n.
- 6. long buccal n.
- Posterior Division Branches:
- 7. auriculotemporal n.
- 8. lingual n.
- 9. inferior alveolar n.
- a. mylohyoid n.
Where along the lingual nerve does it carry VE-para/pre fibers? Where along the lingual
nerve does it carry VE-para/post fibers?
What is “anesthesia”, “paresthesia” and “dysesthesia”?
- anesthesia (numb tongue),
- paresthesia (tingling),
- dysesthesia ( pain and burning )
What is the pterygomandibular space (What are its boundaries?) What does it contain that is important in dentistry?
contains the inferior alveolar nerve and lingual n. (nerves important in dental anesthesia). The myloyoid n. and inferior half of the sphenomandibular lig. are also in this space.
What are the connections of the pterygoid venous plexus?
connections with the facial vein, cavernous sinus, and retromandibular vein.
Where is the pterygoid venous plexus located?
located between the temporalis and pterygoid muscles
What is the relationship of the maxillary artery to the neck of the mandible?
posterior to the neck of the mandible to enter the infratemporal fossa
The maxillary artery is divided into 3 parts: 1st Part, 2nd Part, and 3rd Part. What are the other
- names of these 3 parts?
- (retromandibular) part include the:
- deep auricular a., (external auditory meatus)
- anterior tympanic a. (tympanic membrane)
- middle meningeal a.,
- accessory meningeal a.,
- inferior alveolar a
- (pterygoid) part include the:
- masseteric a.,
- pterygoid a.,
- deep temporal as.,
- buccal a.
- (pterygo-palatine) part include the:
- posterior superior alveolar a.,
- infraorbital a.,
- descending palatine a.,
- artery of the pterygoid canal
- (not depicted),
- pharyngeal a. (not depicted),
- sphenopalatine a.
Which ligament supplies lateral stability to the TMJ?
lateral ligament (a.k.a. “temporomandibular ligament
What is unusual about the cartilage of the TMJ given that it is a synovial joint?
fibrocartilage (rather than hyaline cartilage
The position of the larynx corresponds to which vertebral levels?
bodies of the C3-C6 vertebrae
What is the relationship of the larynx to the trachea?
the larynx is superior to and continuous with the trachea.
What position are the true vocal cords in during respiration? What position are the true vocal cords in during phonation?
- open position as in “respiration.”
- approximated position as in “phonation
What are the two major functions of the larynx?
- (1) it is a phonating mechanism that is designed for voice production, and
- (2) it guards the air passages and maintains an open airway when it serves as a sphincter or valve of the lower respiratory tract.
What is the vocal ligament? What are its attachments?
vocal ligament is the submucosal “skeleton” of the true vocal fold. It is stretched between the arytenoid and thyroid cartilages.
What is the conus elasticus?
2 triangular membranes and 2 vocal ligaments together form the “conus elasticus.” The conus elasticus and overlying mucosa guard the tracheal inlet
Where is the supraglottic cavity?
The vestibule and ventricle can be considered as the “supraglottic cavity
Do the false vocal folds play a role in sound production? What do they do?
false vocal folds (cords) are also called “vestibular folds”. They play no role in sound production. They serve a protective function
32. Describe the blood supply to the larynx (which two arteries are involved and what are their origins?).
superior laryngeal artery – (a br. of superior thyroid a. which accompanies the internal laryngeal n. through the thyrohyoid membrane) and the inferior laryngeal artery (a br. of the inferior thyroid artery from the thyrocervical trunk of the subclavian a
Which nerves supply the lips?
The innervation (SA) is by way of the infraoribital (upper lip) and mental nerves (lower lip).
What is the vestibule?
narrow interval between the lips/cheeks and teeth/gingivae
What is the parotid papilla and where is it located?
The parotid duct opens on the parotid papilla, opposite the 2nd maxillary molar.
What is the action of the uvula?
principle action of the soft palate is to close off the nasopharynx in swallowing, in suckling and during oral speech.
Name the different kinds of papillae on the oral part of the tongue and indicate which ones have taste buds.
- filiform, fungiform, valate and folliate.
- The vallate (a.k.a. “circumvallate”), foliate, and fungiform papillae contain taste buds.
- The filiform papillae contain sensory nerve endings that are sensitive to touch
Which extrinsic muscle of the tongue protrudes the tongue? Which one retracts it? Which one depresses it?
From superior to deep (or inferior to superior), what is the relationship of the genioglossus, geniohyoid, and myloyoid muscles?
Mylohyoid, geniohyoid, genioglossus
Although we cannot see them easily, name the 3 intrinsic muscles of the tongue. What is the general function of these muscles?
- main function is to change the shape of the tongue. They include:
- (1) superior & inferior
- longitudinal muscles
- (2) transverse muscles
- (3) vertical muscles
Which veins allow for quick absorption of medications under the tongue?
enter the deep lingual veins in less than a minute
Lymph from the posterior 1/3rd and medial aspect of the anterior 2/3rd of the tongue drain into which group of lymph nodes?
Lymph from the lateral sides of the anterior 2/3rd of the tongue drains into which nodes?
Lymph from the apex of the tongue drains into which nodes?
What is the sublingual caruncle?
the median fold forms the frenulum of the tongue, on either side of which lies the sublingual caruncle (the opening of the duct of the submandibular gland).
What is the relationship of the lingual nerve to the submandibular duct?
lingual nerve passes from lateral to medial, under the submandibular duct
How does the sublingual gland deliver saliva to the oral cavity?
Which nerves innervate the palatine gingivae of the maxillary teeth?
Greater palatine nerve, nasopalatine nerve
Which of the superior alveolar nerves is sometimes not present in people?
In patients that do not have an MSA nerve, the ASA nerve may also innervate the premolar teeth and mesiobuccal root of the 1st molar.