Submandibular ∆ Flashcards
Describe the size and orientation of the superficial and deep parts of the hook shaped Submandibular gland.
- Lateral
- Cranial
- Caudal
Superficial part (not in oral cav.):
- Lateral = Mandible
- Cranial = Mylohyoid m. and Line of mandible
- Caudal = fascia
Deep part (in oral cav.):
- Lateral = Mandible
- Caudal = Myloihyoid m. and Line of mandible
Course of the Submental Vessels (=> facial a.) and mylohyoid n.
They travel together on the lateral surface of the mylohyoid medial to the mandible
Borders of the Submandibular ∆
Base:
Inferior Border of the Mandible
Sides:
Anterior and Posterior Digastric
What muscles divides into to 2 slips to insert on the hyoid?
- why?
- Stylohyoid
- Divides into 2 slips to straddle the Digastric Tendon
What gland extends around the posterior surface of mylohyoid?
Submandibular
What part of the submandibular gland can be seen through the submandibular ∆ and what muscles is it lying on?
- Superficial Part = Visible part
- Sits on mylohyoid and hyloglossus
What muscles make up the main mass of the tongue?
- orientation
- bony attachment
- Intrinsic Muscles
Orientation:
- Longitudinal
- Verticle
- Transverse
- NO BONY ATTACHMENTS
What nerve innervates all of the intrinsic and extrinsic muscles of the tongue?
- exception?
- CN XII
- Exception = Palatoglossus
What actions are performed by the intrinsic muscles of the tongue?
They can flatten, and round up the tongue
T or F: the extrinsic muscles of the tongue lack bony attachments
FALSE
What do the extrinsic muscles of the tongue do?
- move the mass of intrinsic muscles
What do the majority of mylohyoid fibers insert into?
- which fibers don’t?
- Most fibers insert into the mylohyoid rahpe
- MOST POSTERIOR fibers insert into the hyoid bone
What muscles lie on either side of the mylohyoid raphe?
Anterior Bellies of the R and L digastrics
What are 2 important functions of the mylohyoid muscles?
- Support of the Floor of the mouth
2. Swallowing reflex
What nerve supplies the mylohyoid mm.?
- NERVE ORIGIN
- N. to mylohyoid => Inferior avleoloar n. => CN V3
What is the path of the mylohyoid n. starting with the origin?
- V3 - through foramen ovale
- N. to Mylohyoid branches from Inferior Alveolar n. (IAN) as IAN enters the mandibular foramen
- N. to Mylohyoid runs in the Mylohyoid groove
What runs in the mylohyoid groove?
Mylohyoid N.
Mylohyoid Branch of Alveolar a.
T or F: a branch of the mylohyoid n. (V3) also innervates the posterior digastric
FALSE, it innervates the ANTERIOR digastric
What muscles attach to the superior and inferior mental spines?
Superior Mental Spines:
Genioglossus
Inferior Mental Spines:
Geniohyoid
T or F: the digastric fossa is superior to the mental spines
FALSE, it is below both sets
What muscle separates the anterior digastrics from the geniohyoid muscles?
Mylohyoid muscle
What muscle has fibers that blend with the intrinsic muscles of the tongue and lies just under them?
Genioglossus
What is the action of the geniohyoid when infrahyoid muscles are relaxed?
- Flexed?
- Other functions
Infrahyoid Relaxed:
- Hyoid is mobile and is pulled ANTERIORLY and SUPERIORLY
Infrahyoid Flexed:
- Hyoid is Fixed and mandible is depressed
**Supports the floor of the mouth and is important in swallowing
What innervates geniohyoid and what does it course with?
- C1 from cervical Plexus
- Travels with hypoglossal n. (XII)
**Recall superior root of Ansa Cervicalis and n. to thyrohyoid also travel with this
What are the 4 extrinsic tongue muscles?
- Genioglossus
- Hyoglossus
- Styloglossus
- Palatoglossus
Where do most of the fibers of the genioglossus insert?
- Few lower fibers?
- Intrinsic Muscles of the Tongue
- Lower fibers =Hyoid Bone
Flexing what fibers of what extrinsic tongue muscle allow you to stick your tongue out (protraction)?
- Inferior Fibers of Genioglossus
What does flexing the superior fibers of genioglossus do?
REtraction of tongue
**Tip of Tongue curls back toward inside of mouth
What happens when all fibers or genioglossus, intrinsic muscles, and mylohyoid are all contracted simultaneously?
- importance of this action
- Pushes the tongue against the palate
***Important for propelling food posteriorly to the pharynx
What extrinsic muscle draws down on the side of the tongue and tends to flatten it?
- Hyoglossus
**Is also a retractor of the tongue
What muscles blend into the side of the tongue with hyoglossus?
- Styloglossus
- Palatoglossus
What EXTRINSIC muscle of the tongue forms the ANTERIOR Tonsilar Pillar and what is its innervation?
- Palatoglossus = Anterior Tonsilar Pillar
- CN X
**Note: all other are innervated by CN XII
If you had a lesion in your right hypoglossal n., what would happen when you stuck your tongue out?
- It would deviate to the side of the lesion
T or F: the submandibular duct originates from the superficial part of the gland
False, it originates from the DEEP portion
What is the course of the submandibular ducts and where do they empty saliva?
- Anteriorly and Medially and end in the Sublingual Caruncle
- These lie on either side of the Frenulum
Where does the lingual n. originate?
- Infratemporal Fossa
- Branch of CN V3
Describe the path of the lingual n. as it courses in the oral cavity.
- Loops around the LATERAL side of the Submandibular Duct and passes inferiorly
- Lingual Nerve then courses medially to the submandibular duct to innervate the tongue
What is the frenulum?
Fold of mucosa under the anterior aspect of the tongue
In which salivary gland are stones most common?
- What outlet would this stone need to pass through?
- Submandibular
- Sublingual Caruncle
What gland lies anteriorly in the oral cavity proper, just beneath the mucosa?
- Sublingual Gland
**Note since this gland is mostly mucous, its secretions are very viscous
T or F: the sublingual gland empties into a single duct just anterior the the sublingual Caruncle.
False, 10-12 duct empty POSTERORLY to the Sublingual Caruncle
Where is the submandibular ganglion located?
- ganglion type
- Between the Lingual N. (=> V3) and the submandibular gland
- PARASYMPATHETIC ganglion
what 2 nerves pass on the superficial surface of the hyoglossus muscle and what artery passes beneath?
- relative location
Nerves:
1. Lingual n. (superior, deeper) - nearer to insertion into the tongue
- Hypoglossal n. (inferior, more superficial) - nearer to origin on the hyoid
Artery:
- Lingual a. (=> external carotid)
T or F: the lingual artery and nerve course together.
False
Describe the course of the Lingual a.
Branches from external Carotid
1. Deep to posterior digastric and Stylohyoid mm.
- Beneath hyoglossus muscle
- INTO the tongue
Describe the course of the lingual n.
Originates from V3 in INFRATEMPORAL Fossa
1. Posteriorly Lies along LATERAL side of styloglossus
- Crosses medially onto hyoglossus
- Connects to submandibular ganglion then continues forward
What does the lingual n. do?
- Retrieves GSA info. from ANTERIOR 2/3 of the tongue
- GSA to floor of mouth
- GSA to lingual Gingiva
What marks the boundary between the anterior 2/3 of the tongue and the posterior 1/3?
Circumvallate Papillae
Where are the cell bodies for the lingual n. fibers innervating the floor of the mouth and lingual gingiva of the mandible?
Semilunar Ganglion
**This is found in the middle cranial Fossa
What boundaries define the paralingual space?
- V-Shaped interval between the Mylohyoid and Hyoglossus
What artery courses deep to the superficial part before emerging from under the mandible to reach the face?
Facial artery
**Note: facial vein course not on the deep side, but the SUPERFICIAL side of the submandibular gland
T or F: infections from abscessed teeth and gingiva can easily travel in the paralingual space
True
What provides special sensory information and parasympathetic supply to submandibular and sublingual Glands?
CN VII
Where are the cell bodies for the lingual nerve located?
Trigeminal Gangion
What nerve supplies GSA to the posterior 1/3 of the tongue?
- Cell body location?
- CN IX
- Sensory Ganglia of IX and X or just below jugular foramen
What branch of CN VII carries SA taste fibers from the anterior 2/3 of the tongue?
Chorda Tympani
Where are the cell bodies for the SA fiber of CN VII located?
Geniculate Ganglion
periferal sensory ganglia CN VII
T or F: BOTH taste and GSA from the posterior 1/3 of the tongue is from CN 9
True
What 2 fiber types can be found in chorda tympani?
- SA fibers for anterior 2/3 of the tongue
2. PREganglionic Parasympathetic (GVE) Fibers
Where do the preganglionic parasympathetic fiber running in Chorda Tympani come from and where are they running to?
From:
Motor Nuclei of VII in the Brain
To:
Submandibular Ganglion
What types of cell bodies are found in the submandibular ganglion?
- Postganglionic Parasympathetic Neurons
What is the destination for the Postganlionic Axons leaving the Submandibular ganglion?
- Directly to Submandibular
2. Return to lingual n. and travel to Sublingual Gland
What is the course of the lingual n. over the styloglossus m.?
- Lateral to medial to get to the hyoglossus m. surface
What is the position of the facial a. and v. relative to the submandibular gland?
Superficial to SUPERFICIAL pt. of gland:
- Facial v. => Deep facial => Pterygoid Plexus
DEEP to SUPERFICIAL pt of galnd:
- Facial a. => Ext. carotid