Flashcards in Downing: Histology of the Oral Cavity and Esophagus Deck (61):
What forms the inner lining of tubular organs?
What are the four components of the mucosa?
What is the muscularis mucosa composed of?
Smooth muscle (can lack or be replaced by elastic fibers)
What composes the submucosa?
Loose connective tissue
Large blood vessels
Submucosal nerve plexus
What composes the supporting wall?
Smooth or skeletal muscle, bone or cartilage (muscle is several different oriented layers)
What composes the adventitia?
What are the surface features of the lip?
1. Cutaneous area- stratified squamous keratinizing epithelium (sweat glands, hair)
2. Red area- stratified squamous non-keratinizing (papilla)
3. Oral mucosa- stratified squamousn on-keratinizing (glands)
What does the submucosa of the lip contain?
not distinguishable b/c blends w/ the mucosa
What does the supporting wall of the lip contain?
skeletal muscle of the orbicularis oris
Describe the structure of the cheek.
1. Mucosa and submucosa- like hte lip, ELASTIC tissue in submucosa
2. Supporting wall- BUCCINATOR
Describe the structure of the hard palate.
1. Mucosa- st. sq. keratinizing, LP (papilla w/ vascular core)
2. Submucosa- absent in midline, anterior 1/2 FAT, posterior 2/3 mucus glands
3. Supporting wall- BONE
Describe the structure of the soft palate.
1. Mucosa- st. sq. keratinizing (oral) and pseudostratified columnar ciliated (nasal) + LP
2. Submucosa- mixed glands
3. Supporting wall- skeletal muscle and connective tissue
What is on the ventral surface of the tongue?
stratified sq. non-keratinizing
mixed glands beneath epithelium
What is on the dorsal surface of the tongue?
1. Mucosa- st. sq. keratinizing, LP forms papillae
2. Skeletal muscle in three planes
3. Nerve supply
Where are serous glands found in the mucosa of the tongue?
below the circumvallate papillae
Where are mucous glands found in the tongue?
What supplies the anterior 2/3 of the tongue?
CN V and VII
What supplies the posterior 2/3 of the tongue?
IX and X
What are the most numerous papillae of the tongue?
PARALLEL rows across tongue
keratinization most obvious near apical portion
What are the fewest papillae of the tongue and where are they located?
TIP of tongue
What shape do the fungiform papillae have?
Appear as RED structures
Where are taste buds on the tongue found?
In the epithelium--NOT numerous
What nerve supplies the taste buds?
What papillae are found adjacent to the sulcus temrinalis?
Why are circumvallate papillae like a turreted castle?
Each are surrounded by a moat or trench
What are found on the sides of circumvallate papillae? What CN supplies them?
What are the glands of von ebner? What do
Serous glands in the LP of the circumvallate papillae EMPTY into the trench and wash out the area
What are the foliate papillae?
poorly developed in humans, taste buds associated w/ the epithelium of hte circumvallate papillae
What are the three types of cells that make up the taste buds?
1. Sustentacular- long, thin, project into taste pore
2. Taste receptor cells- long thin, project into taste poor
3. Basal cells- give rise to the first two!
What do taste buds do?
perceive taste (salt sweet sour bitter)
How long do your taste buds last?
Constant turn over
sectioning of nerves in taste buds > degeneration and disappearance of taste buds> buds regenerate in 10 days when nerve is reconnected and nerve fibers are regenerated
What produces enamel and what does it consist of?
3% protein and 97% mineral
What produces dentin?
30% organic matter
What produces cementum? What does it do?
Anchors tooth to peridontal ligament
What produces the peridontal ligament? What does it do?
Anchors tooth to alveolar bone
What is the origin of the dental lamina?
What does the dental lamina give rise to?
enamel (primary teeth)
What is the origin of the dental papilla?
What gives rise to cells which form dentin?
Dental papilla (primary teetch)
What separates the lip and cheek from developing gums and teeth?
What do the tooth germs for permanent tooth develop from?
dental lamina on lingual side of primary teeth
What is the difference between ameloblasts and odontoblasts?
Ameloblasts: develop from dental lamina, produce enamel during tooth growth, but are lost w/ tooth development
Odontoblasts: develop from dental papilla, produce dentin during tooth growth and some throughout life
What are hte major salivary glands?
What are the minor salivary glands?
mucous serous glands in lamina propria and submucosa of oral cavity
How much saliva do humans produce?
1000-1500 ml saliva/day
What are the functions of saliva?
lubrication and moistening
WASHES mouth of debris
MOISTENS food for easy swallowing and tasting
ENZYMES initiate digestion
What is the morphology of salivary glands?
CT capsule (esp parotid)
Divided into lobes and lobules
Interlobar/interlobular areas supported by CT
Stratifed sq non-keritenizing epithelium in oral cavity but most is SIMPLE COLUMNAR w/ some stratified columanr/cuboidal
simple columnar or high cuboidal
STRIATIONS ARE EOSINOPHILIC
cuboidal or low cuboidal
What is the difference between mucous and serous alveolus?
both are cuboidal or columnar
mucous- nuclei compressed near base of cell
serous- distinct nuclei
What are the myoepithelial cells?
Specialized smooth muscle cells BETWEN serous and mucous cells
help to PUSH PRODUCT into the duct system
What are demilunes?
Secretory units that contain both serous and mucous cells
formed by SEROUS secreting cells
occupy the BLIND END of the secretory unit
What are characteristics of the parotid gland?
Well defined capsule w/ CT btween
Striated and intercalated are prominent
Acini: almost 100% SEROUS
What are the characteristics of the submandibular gland?
CT present but not as well defined as parotid
STRIATED DUCTS well defined but not intercalated
Acini: 10-25% mucous (capped by demilunes), but majority SEROUS
What are the characteristics of the sublingual gland?
Excretory ducts prominent
Striated ducts not prevalent in tissue w/ no intercalated ducts
Acini are 75% MUCOUS CELLS w/ majority serous demilunes
Describe the mucosa of the esophagus.
Stratified sq. non-keratinizing (replaced every 2-3 days)
LP (mucous glands)
Muscularis mucosa (smooth muscle fibers)
Mucous glands in the lamina propria of the mucosa are prominent in what parts of the esophagus?
cardiac glands in the UPPER and LOWER thirds
Where are the mucous secreting glands in the submucos? What plexus is found there?
Submucosal nerve plexus
How does the muscularis externa differ in the upper, middle and lower parts of the esophagus?
middle- smooth w/ some skeletal
lower- smooth muscle