What nerve is the buccinator innervated by? What is it's role?

- facial n

- along with the tongue it positions food between the teeth for chewing

What structures are found within the vestibule?

- opening of parotid duct (opposite the upper second molar tooth

- minor salivary glands (labial and buccal glands of the lips and cheeks)

- labial frenulum

What's the diff between the hard palate and the soft palate and what do they each do?

- hard palate is formed by palatine processes or the maxillae and horizontal plates on the palatine bones between the nasal and oral cavity. Non fusion of the palatal processes: cleft palate!) The hard palate also has palatal minor salivary glands.

- soft palate is a fibromuscular fold attached to the posterior aspect of the hard palate. it moves posterosuperiorly to close the nasopharynx and antroinferiorly to close the oropharyngeal isthmus.

Describe the structural elements of the soft palate

- mostly made up of the palatine aponeurosis which is the flattened tendon of the tensor veli palatini

1. Tensor veli palatini: tenses the soft palate through that aponeurosis and also opens the pharyngotympanic tube (during deglutition and yawning, it equalizes air pressure between middle ear and nasopharynx

2. Levetor veli palatini: elevates the soft palate (separates the nasop from the orop)

3. Palatoglossus: draws soft palate into tongue and elevates root of the tongue

4. Palatopharyngeus: elevates pharynx and pulls palatopharyngeal arch medially

5. Musculus uvulae: elevates uvula

What nerves and vessels supply the palate?

Blood supply: greater and lesser palatine a

Hard palate:

Somatosensory: greater palatine n, branches of maxillary (CNV), anterior part from nasopalatine n (through incisive foramen)

Soft palate:

Somatosensory: lesser palatine n

Somatomotor: all vagus via the pharyngeal plexus except tensor veli palatini (CN V)

Palatal salivary glands: CN VII

What are the 2 muscles of the very very base of the oral cavity?

Mylohyoid: 1st branchial arche muscles and are innervated by CN V (via mylohyoid n, a branch of the inferior alveolar n). This is the absolute lowest muscle.

Geniohyoid muscle: related to the strap muscles of the neck (innervated by a branch of C1 that travels with the hypoglossal n)

Describe the external features of the tongue

- divided into 2 parts by V shaped depression, called SULCUS TERMINALIS. Anterior 2/3 = oral part, has lots of papillae

- Filiform p: highly keratinized and lack of taste buds (in the middle)

- Fungiform p: has taste buds, (in the front)

- Foliate p: has taste buds (on the sides)

- Circumvallate p: has taste buds (at the back)

Posterior 1/3 = pharyngeal part

- the mucous membrane has no papillae, but plenty of lymphoid follicles (lingual tonsil) and mucous glands

What are the intrinsic muscles of the tongue?

- These are interdigitated fibres with three different orientations: longitudinal (more superior in the tongue), transverse and vertical.

- These fibres widen the tongue as they shorten it. The longitudinal ones are largely responsible for the shortening.

Describe the extrinsic muscles of the tongue

Palatoglossus: elevates tongue. It's a branchial arch muscle and is innervated by CN X via the pharyngeal plexus.

Styloglossus: retracts and elevates tongue

Hyoglossus: depresses and retracts tongue

Genioglossus: protrudes and depresses tongue (remember we saw this one before! Just kidding we didn't! That was the GenioHYOID, it was one of the lower muscles in the oral cavity but not quite as deep as the mylohyoid!) This guy is important for maintaining an open nasopharynx! During anesthesia we don't want this musce to become paralyzed and occlude the airway! (which can happen)

Where does the tongue get it's blood supply?

What 2 bones make up the hard palate?

Describe the nerve supply to the tongue

Sensory

Anterior 2/3

- General sensory: trigeminal (mandibular nerve via lingual nerve)

- "Viscerosensory", meaning taste: facial nerve via the chorda tympani

Posterior 1/3

- Taste and general: CN IX.

Root

- Somatosensory/viscerosensory: vagus nerve

Motor

- all by CN IX except palatoglossus which is vagus

Where is the parotid gland? What innervates it? What type of tissue is it made up of? What structures pass through it?

- it is a salivary gland, in the retromandibular space, covered by a dense fibrous capsule, and secretes serous saliva.

- The duct goes accross the masseter, and PIERCES the buccinator, and opens into the mouth opposite the upper second molar tooth.

- The external carotid a., the retromandibular vein, and the facial nerve pass through it

- it's innervated by CN IX (not CN VII like the other salivary glands)

Where and what are the submandibular glands? What do they secrete? Where does the duct go?

- they are salivary glands below the myohyoid and mandible, and they secrete a mix of serous and mucus saliva (superficial and deep part) *the parotid just secreted serous saliva

- the duct runs through the lateral space of the tongue with the hypoglossal nerve and the lingual nerve (the lingual nerve loops under the duct)

- opens on an elevation, the sublingual papilla.

What are the sublingual glands? Where are they?

- salivary glands secreting both mucus and serous saliva, but mostly mucous.

- it's the smallest of the 3 glands.

- duct opens at floor of oral cavity

- gland located between mandible and genioglossus muscle

Describe the course of CN IX to the parotid gland

Describe the course of the facial nerve as it goes to innervate the submandibular and sublingual glands

For the innervation of the face, it's split up into two regions in relation to the oral fissure... describe those innervations

- all glands above oral fissure are innervated by greater petrosal of VII except parotid (IX)

- all glands below oral fissure innervated by chorda tympani of VII.

How many teeth do we have as our baby teeth compared to when we're an adult?

- baby teeth: 20. 2 incisors, 1 canine, and 2 molars in each half of both the jaws). They begin to errupt at 6 mo and are all erupted by end of second year

- adult teeth: 32. 2 incisors, 1 canine, 2 premolars and 3 molars in each half of the 2 jaws.

In what order do the permanent teeth errupt?

- 1st molar (6 y)

- medial incisor (7y)

- 2nd premolar (10 y)

- canine (11 y)

- 2nd molar (12 y)

- 3rd molar, or wisdom tooth, (~17-25 y)

Describe the tissues in the tooth

- so the surface that you chomp down on in the crown, then there's the neck, then the root.

- Enamel: hardest substance in the body (ameloblasts make it), its on the outermost part of the crown.

- Dentin: calcified material that forms most of the tooth substance (odontoblasts make it)

- Cementum: covers the root of the tooth (cemntocytes make it)

Describe the blood supply to the teeth and gums as well as their nerve supply.

Blood: superior and inferior alveolar arteries, branches of the maxillary artery

Nerve: superior and inferior alveolar nerves, branches of the maxillary and mandibular nerves

Where is the temporalis muscle and what does it do?

Where is the masseter muscle and what does it do?

Where are the medial ptergoid muscles and what do they do?

Where are the later ptergoid muscles and what do they do?

- origin is on the infratemporal crest and lateral surface of the lateral ptergoid plate of the sphenoid. Insertion at the TMJ. Action is opening the jaw.

*The medial and lateral ptergoids work together to make side to side movements during mastication.

Describe the TMJ

- synovial joint: between the condylar process of the mandible and the squamous portion of the temporal fossa.

- it's articular disc divides the joint into an upper component which permits a gliding movement and a lower comparment which permits rotation.

- ROM: depression, elevation, protraction, retraction, lateral or side to side

- blood supply is the superficial temporal and maxillary arteries

- nerve supply: auriculotemporal and masseteric nerve

What's the "oropharngeal isthmus"

What's the real definition for the "pharynx"

Describe the muscles of the pharynx.

Two major divisions: constrictors and elevators

Constrictors: Superior, middle and inferior constricter. Each one is thicker than the one above and they kindof look liek a pile of ice cream cones

Elevators: stylopharyngeus, palatopharyngeus, salpingopharyngeus.

In the pharynx there must be some tonsil stuff, describe that stuff.

- Pharyngeal tonsils at the back of the nasopharynx, palatine tonsils are the ones we always think of, then the lingual tonsils are the ones at the back of the tongue.

- There is the pharyngeal lymphoid ring (or Waldeyer's tonsillar ring), which is a ring of lymphoid tissue that encircles the nasopharynx and oropharynx.

What is the blood supply and the nervous supply to the pharynx?

Blood: pharyngeal branch of maxiallary a., of the superior and inferior thyroid arteries and the ascending pharyngeal a.

Nerve: comes from the PHARYNGEAL PLEXUS which lies on the middle pharyngeal constrictor and is formed by the pharyngeal branches of CN IX, X and the sympathetic nerve from the superior cervical ganglion.

Motor: Vagus does all muscles of the pharynd, except stylopharygeaus (IX) and tensor veli palatini (V)

Sensory:

- V2: nasopharynx

- IX: oropharynx

- X: laryngopharynx

Describe the landmark you use to tell where the esophagus starts, what is the narrowest part of it?

- it begins in the neck at the lower border of the cricoid cartilage (at C6)

- The pharyngoesophageal junction is the narrowest part.

Describe the anatomical things aroung the esophagous in both the cervical part and the thoracic part

Cervical: trachea in front, vertebral column posteriorly, common carotid arteries and thyroid gland on either side.

Thoracic: same stuff anterior and posteriorly, to the right is the azygous vein and right lung pleura, to the left is the aortic arch and the left lung pleura.

What are the 3 constrictions of the esophagus?

1. Cervical: at the beginning of the pharyngoesophageal junction, caused by cricopharyngeus muscle

2. Thoracic: where it's crossed by the aortic arch and left bronchus.

3. Diaphragmatic

What is the pharyngeal diverticulum (otherwise known as Zenker's Diverticulum)