Term
| the oral mucosa is which type of epithelium? |
|
Definition
statified squamous typically non-keratinized epithelium
rests on a basal lamina as do all epithelia
keratinization can occur in the regions of the gingiva (gums) and hard palate, which receive a lot of mechanical stress from chewing
non-keratinized epithelium in the area of the cheeks can be quite thick
in the floor of the mouth it can be quite thin and permeable thus making it a good place for the administration of drugs such as nitroglycerine for angina pectoralis.
Immediately under the epithelium and its basal lamina is a lamina propria
typically loose connective tissue
However, in areas subjected to extreme forces of mastication, dense connective tissue (areas of the palate and gingiva) which may extend into connective tissue papillae.
In most places, underlying the lamina propria is a submucosa
can contain small, diffuse salivary glands
In places where food is crushed or rubbed as in the case of the hard palate or gingiva (gums), there is no submucosa and the mucosa is directly and tightly attached to the underlying periosteum. |
|
|
Term
|
Definition
caused by tobacco use, alcohol, local irritation
a white patch which may be precancerous |
|
|
Term
| what is a squamous cell carcinoma? |
|
Definition
most common malignancy of the oral cavity
caused by tobacco use, alcohol, and local irritation |
|
|
Term
| describe the lips and which muscle composes them |
|
Definition
Mobile, fleshy muscular folds.
Core of muscle, orbicularis oris m.
Also superior and inferior labial muscles.
Upper lip has a vertical groove, the philtrum. |
|
|
Term
| what is the blood supply to the upper and lower lips? |
|
Definition
Upper lip is supplied by the superior labial branches of the infraorbital and facial arteries.
Lower lip supplied by inferior labial branches from the mental and facial arteries. |
|
|
Term
| which nerves innervate the upper and lower lip? |
|
Definition
Upper lip is supplied by the superior labial branches of the infraorbital nerve (V2).
Lower lip supplied by inferior labial branches from the mental nerve (V3).
Motor
Facial nerve |
|
|
Term
| describe the lymphatic drainage from the lips |
|
Definition
Drainage from upper and lateral parts of lower lip goes to submandibular nodes.
Drainage from medial parts of lower lip goes to submental nodes. |
|
|
Term
| what are the 3 distinct regions of the lips |
|
Definition
Three distinct regions.
The external surface - thin skin with hair follicles, sweat and sebaceous glands.
The vermillion zone –transitional region.
It is only found in humans.
It is covered by a stratified squamous keratinized epithelium devoid of hair follicles and sweat glands. There can be occasional sebaceous glands.
It appears red because of the rich vasculature that extends into the very high dermal papillae.
The inner surface is a mucous membrane.
Stratified squamous, non-keratinized epithelium. |
|
|
Term
| what is the principle muscle found in the cheek? what is the function of the cheeks? |
|
Definition
Similar structure to lips.
Principle muscle is buccinator m.
Innervated by the facial nerve.
Helps keep food between the teeth while chewing.
Dennervation makes it difficult to effectively chew.
Duct of parotid gland (Stensen’s duct) opens opposite 2nd maxillary molar. |
|
|
Term
| how many teeth do children have? |
|
Definition
| Children have 20 primary (deciduous) teeth. |
|
|
Term
| adults have how many teeth in each jaw? |
|
Definition
Adults have 16 teeth in each jaw.
On each side of each jaw:
3 molars
2 premolars
One canine
2 incisors |
|
|
Term
| the upper teeth are innervated by which nerve? |
|
Definition
| Upper teeth innervated by superior alveolar nerve (V2). |
|
|
Term
| the lower teeth are innervated by which nerve? |
|
Definition
| Lower teeth innervated by inferior alveolar nerve (V3). |
|
|
Term
| what is the difference between a clinical and anatomical crown of a tooth? |
|
Definition
crown- covered by enamel
clinical crown - portion of tooth above the gingiva (gums)
anatomical crown - entire portion covered by enamel |
|
|
Term
| where is the root of a tooth? |
|
Definition
portion of tooth below gingiva
covered by cementum |
|
|
Term
| what can be found surrounding and inside of the pulp cavity/root canal of a tooth? |
|
Definition
surrounded by dentin
contains loose C.T., blood vessels, lymphatics, NERVES and a layer of odontoblasts (neural crest derived cells). |
|
|
Term
| what is the periodontal ligament in the tooth? |
|
Definition
dense collagenous connective tissue
specialized tissue that attaches the cementum of the root to the surrounding aveolar bone
serves as the periosteum of the alveolar bone and absorbs the shock of mastication
highly vascular and has a high turnover of collagen
deficiencies of proteins and vitamin C (scurvy) - atrophy of the ligament and consequent loss of teeth |
|
|
Term
|
Definition
| deficiencies of proteins and vitamin C (scurvy) causes atrophy of the periodontal ligament and consequent loss of teeth |
|
|
Term
| describe what periodontal sensation means |
|
Definition
There are mechanoreceptors in the periodontal ligament. These mechanoreceptors are involved in a reflexive control of bite force.
If one bites on a hard object, e.g. olive pit in Greek salad, the jaw reflexively opens.
Prevents damage to the teeth |
|
|
Term
| describe alveolar bone of the tooth |
|
Definition
immature, woven bone
contain tooth sockets (alveoli)
quite plastic and can be changed over time by the use of orthodontic appliances (braces) |
|
|
Term
|
Definition
gums
mucous membrane having partially keratinized or keratinized epithelium
firmly attached to the underlying periosteum of the mandible or maxillary bone
epithelium is bound to the tooth enamel by a thick basal lamina (cuticle) called the epithelial attachment of Gottlieb. |
|
|
Term
|
Definition
calcified tissue
harder than bone
has a higher content of calcium salts (70% hydroxyapatite)
organic matrix made up of type I collagen, proteoglycans and glycoproteins |
|
|
Term
| where are odontoblasts derived from and what do they secrete? |
|
Definition
neural crest origin
secrete organic matrix (predentin)
line the pulp cavity
have long slender processes that penetrate perpendicularly through the dentin
processes called Tomes fibers
canals in which the odontoblast processes are found are called dentinal tubules |
|
|
Term
|
Definition
hardest substance in the body (95% hydroxyapatite)
organic matrix contains enamel proteins but no collagen
contains no cells in the adult
Ameloblasts, which arise from the ectodermal enamel organ, secrete the enamel matrix during tooth development.
The enamel organ does not persist in the adult tooth. |
|
|
Term
|
Definition
similar to bone, i.e. a calcified tissue
has no Haversian systems or blood vessels
matrix is secreted by cementoblasts
contains type I collagen, proteoglycans and glycoproteins
thicker in the apical region of the root and this is the only place cementocytes within lacunae are seen
cementocytes, like osteocytes, communicate via canaliculi |
|
|
Term
|
Definition
Bacteria accumulate in defects in enamel
Produce acids that decalcify enamel
Flouride, particularly in younger individuals, hardens enamel |
|
|
Term
| describe the dorsum of the tongue |
|
Definition
divided by a V-shaped boundary (sulcus terminalis) into anterior 2/3 and posterior 1/3.
V has its tip directed posteriorly
Location of foramen caecum (location of embryological thyroid diverticulum).
division reflects the different embryological origins of the two parts of the tongue
anterior 2/3 or oral part of the tongue - 1st branchial arch
posterior 1/3, pharyngeal part – 3rd and 4th arches |
|
|
Term
| what are the four types of papillae found on the tongue? |
|
Definition
filiform papillae
fungiform papillae
foliate papillae
circumvallate papillae |
|
|
Term
| what are filiform papillae? |
|
Definition
numerous projections from the surface of the tongue.
have a C.T. core
partially keratinized epithelium
no taste buds
give the dorsal surface of the tongue its rough feel |
|
|
Term
| what are fungiform papillae? |
|
Definition
Mushroom-shaped
have thin stalks and smooth-surfaced, dilated upper portions
scattered among filiform papillae
have taste buds on dorsal surface |
|
|
Term
| where are foliate papillae found? |
|
Definition
poorly developed in humans
found on dorsolateral surface of tongue
have taste buds |
|
|
Term
| what are circumvallate papillae? |
|
Definition
1-15 large round papillae along the sulcus terminalis
each surrounded by a moat-like structure into which empty the serous glands of von Ebner
secretions of von Ebner's glands wash away food particles in the moats to allow the numerous taste buds on lateral surfaces of the papillae be exposed to new tastes. |
|
|
Term
| what is the function of the extrinsic muscles of the tongue? |
|
Definition
Extrinsic muscles alter the position of the tongue.
Arise outside of tongue and attach to it.
Genioglossus, hyoglossus, styloglossus and palatoglossus. |
|
|
Term
| what is the function of the intrinsic muscles of the tongue? |
|
Definition
Intrinsic muscles alter the shape.
Completely confined to tongue.
Not attached to bone.
Longitudinal, transverse and vertical. |
|
|
Term
| describe the genioglossus muscle and its function |
|
Definition
Origin – superior part of mental spine of mandible
Insertion – dorsum of tongue and hyoid bone (body)
Innervation – hypoglossal nerve (XII)
Action – depresses tongue, posterior part protrudes tongue |
|
|
Term
| describe the hypoglossus muscle and its function |
|
Definition
Origin – body and greater horn of hyoid bone
Insertion – side and inferior aspect of tongue
Innervation – hypoglossal nerve (XII)
Action -depresses and retracts tongue |
|
|
Term
| describe the styloglossus muscle and its function |
|
Definition
Origin – Styloid process and stylohyoid ligament
Insertion – side and inferior aspect of tongue
Innervation – hypoglossal nerve (XII)
Action – retracts tongue and draws it up during swallowing to form a trough. |
|
|
Term
| describe the palatoglossus muscle and its function |
|
Definition
Origin – Palatine aponeurosis of soft palate
Insertion – side of tongue
Innervation – Cranial nerve X.
Action – elevates posterior tongue |
|
|
Term
| what does hypoglossal nerve injury cause? |
|
Definition
| Because of the actions of the genioglossus muscle, an injury to the hypoglossal nerve causes the protruded tongue to point toward the side of the nerve damage |
|
|
Term
| what is the palate and what are its 2 parts? |
|
Definition
Arched roof of oral cavity
Two parts:
Anterior – hard palate
Formed by palatine processes of maxillary bones and horizontal plates of palatine bones.
Has three pairs of foramina.
Incisive fossa –transmits nasopalatine nerves
Greater palatine foramen – transmit greater palatine nerve and vessels
Lesser palatine – transmits lesser palatine nerve and vessels.
Posterior – soft palate
Muscular part of palate. |
|
|
Term
| describe characteristics of the soft palate |
|
Definition
Muscular curved free margin that is suspended from the posterior hard palate.
Hanging from the hard palate is a conical muscular process, the uvula.
Strengthened by the aponeurosis of the tensor veli palatini muscle.
Prevents passage of food into nasal cavity during swallowing.
Joined to tongue and pharynx by the palatoglossal and palatopharyngeal folds. |
|
|
Term
| describe the tensor veli palatini muscle and its function |
|
Definition
muscle of the soft palate
Origin – medial pterygoid plate, spine of sphenoid bone, cartilage of tympanic tube
Insertion – palatine aponeurosis
Innervation – V3
Action – tenses soft palate, opens tympanic tube during swallowing and yawning |
|
|
Term
| describe the levator veli palatini muscle and its function |
|
Definition
muscle of the soft palate
Origin – cartilage of tympanic tube and petrous part of temporal bone
Insertion – palatine aponeurosis
Innervation – cranial nerve X
Action – elevates soft palate during swallowing and yawning |
|
|
Term
| describe the palatoglossus muscle and its function |
|
Definition
Origin – Palatine aponeurosis of soft palate
Insertion – side of tongue
Innervation – Cranial nerve X.
Action – elevates posterior tongue |
|
|
Term
| describe the palatopharyngeus muscle and its function |
|
Definition
Origin – hard palate and palatine aponeurosis
Insertion – lateral wall of pharynx
Innervation – cranial nerve X.
Action – Tenses soft palate and pull wall of pharynx superiorly, anteriorly and medially during swallowing. |
|
|
Term
| describe the uvular muscle and its function |
|
Definition
Origin – posterior nasal spine and palatine aponeurosis
Insertion – mucosa of uvula
Innervation – cranial nerve X
Action – shortens uvula and pulls it superiorly. |
|
|
Term
| when will the uvula deviate to one side? |
|
Definition
When there is an injury to cranial nerve X, on examination of the oral cavity, the uvula will deviate to the opposite side.
Also, the palatoglossus muscle will not contract on the affected side. |
|
|
Term
| describe the mylohyoid muscle and its function |
|
Definition
Origin – mylohyoid line of mandible
Insertion – raphe and body of hyoid bone
Innervation – mylohyoid nerve, a branch of inferior alveolar nerve (V3)
Action – elevates floor of mouth during swallowing and speech |
|
|
Term
| describe the geniohyoid muscle and its function |
|
Definition
Origin – inferior mental spine of mandible
Insertion – body of hyoid bone
Innervation – C1 via hypoglossal nerve
Action - draws hyoid anteriorly and superiorly during swallowing |
|
|
Term
| describe the anterior belly of digastric muscle and its function |
|
Definition
Origin – digastric fossa of mandible
Insertion – intermediate tendon to greater horn of hyoid bone.
Innervation – nerve to mylohyoid (V3)
Action – depresses mandible, raises and stabilizes hyoid bone |
|
|
Term
| what are the 3 major salivary glands? what is the function of saliva? |
|
Definition
3 major glands
Parotid
Submandibular
Sublingual
produce saliva for lubrication, initial enzymatic digestion of carbohydrates, and antibacterial activity |
|
|
Term
| what are the 2 types of secretory cells in salivary glands? |
|
Definition
serous cells
Pyramidal-shaped cells with spherical nuclei. Contain large amounts of RER and therefore, basophilic cytoplasm characteristic of protein-secreting cells. Serous cells form spherical acini and produce a protein-rich, watery secretion.
mucous cells
Cuboidal or columnar cells. Nuclei are oval or flattened and are pushed to the basal side of the cell by secretory product. Mucinogen granules occupy apical end of cells. In H and E, mucinogen lost, apex of cells have clear, empty appearance. The cells are typically are arranged as tubules. Mucin composed of glycoprotein and is a viscous secretion. |
|
|
Term
| what are serous demilunes? |
|
Definition
| crescent-shaped caps of serous cells on mucous tubules. Most common in the sublingual gland. Secrete lysozyme, an enzyme that breaks down bacterial walls. |
|
|
Term
| where are myoepithelial cells located in salivary glands and what are their function? |
|
Definition
| contractile epithelial cells. They lie between the basal lamina and glandular epithelial cells. Their function is to help move secretory products out of the glands. When they are found in the acini, they often have a stellate-shape and are called basket cells. |
|
|
Term
| what are the 3 types of ducts found in salivary glands? |
|
Definition
intercalated ducts (intralobular): small ducts with squamous or cuboidal epithelium. They are continuous with lumen of acini. The intercalated ducts lead to striated ducts.
striated ducts (intralobular): usually have simple columnar epithelium with basal striations (invaginations) and numerous mitochondria. The striated ducts are involved in ion transport. These ducts lead to excretory ducts.
excretory ducts (interlobular): large ducts within the interlobular connective tissue. They have stratified cuboidal or stratified columnar epithelia. They ultimately empty into the oral cavity. |
|
|
Term
| what are some characteristics of the parotid gland? |
|
Definition
produces 25% of salivary volume
largest of the major salivary glands
completely serous gland
secretory granules contain polysaccharides and are rich in proteins - high amylase activity
characterized by numerous striated ducts
histologically, striated ducts distinguish parotid gland from exocrine pancreas
may have numerous fat cells.
Connective tissue contains plasma cells and lymphocytes.
Plasma cells produce IgA that complexes with a secretory component produced by the serous acinar and duct cells. |
|
|
Term
| what is the mumps virus and what does it cause? |
|
Definition
Mumps virus is single stranded RNA virus
Human is only reservoir
In USA, still substantial numbers of unvaccinated children
Characterized by parotid gland swelling
Can cause meningitis and epididymo-orchitis |
|
|
Term
| describe the submandibular gland and the type of ducts that are most numerous |
|
Definition
called submaxillary gland by British anatomists
responsible for 70% of salivary volume.
In man, the submandibular gland is a mixed gland, i.e. serous and mucous, although primarily serous. Serous cell granules contain carbohydrate moieties and protein. Serous cells have extensive lateral and basal membrane infolding suggesting their role in electrolyte and water transport. These infoldings make the cell boundaries indistinct.
serous demilunes are associated with mucus acini.
cells of the serous demilunes secrete lysozyme.
gland has numerous, easily visible striated ducts |
|
|
Term
| describe the sublingual gland |
|
Definition
contributes 5% of the salivary volume
In man, the sublingual gland is a mixed gland, but predominently mucous.
The serous cells are only usually found in serous demilunes.
The sublingual gland has very few striated ducts and they are difficult to identify. |
|
|
Term
| what is the pharyngeal tonsil? |
|
Definition
Actually in roof of nasopharynx
Shallow infoldings called pleats
Covered by pseudostratified columnar epithelium (respiratory epithelium)
Inflamed pharyngeal tonsil is called adenoid |
|
|
Term
| what is a palatine tonsil? |
|
Definition
Bilateral, located between palatoglossal and palatopharyngeal folds
Deep aspect has dense fibrous capsule
Covered by stratified squamous non-keratinized epithelium
Has deep crypts that trap food particles, etc. |
|
|
Term
| what is a lingual tonsil? |
|
Definition
Located in posterior 1/3 of tongue
Covered with stratified squamous non-keratinized epithelium
Each lingual tonsil has a single crypt |
|
|
