Oral cavity Flashcards
Which organs and glands are associated with the digestive tract?
- Oral cavity
- Pharinge
- Esophague
- Stomach
- Small and large intestines
- Rectum
Associated glands: - Salivary glands
- Liver
- Pancreas
Where does the 1st step of digestion occur?
1st step of digestion occurs in the mouth food is moistened by saliva + grounded by the teeth + saliva initiates digestion of carbohydrates
*Food doesn’t stay in the mouth long enough for complete digestion of carbs
What includes the oral mucose (which lines the oral cavity)?
- nonkeratinized stratified squamous epithelium (resting on BM, squamous but do contian a nucleus)
- Lamina Propria of loose CT → very vascular
*LP is continuous with a submucosa of denser CT containing diffuse small salivary glands (serous, mucous or mixed)
*Oral mucosa covers entire inside of the mouth except gingiva and dorsal surface of the tongue, which are specialized mucosae
Which epitheliums are keratinized or not in the oral cavity?
Oral cavity in general → nonkeratinized
Lip → transition from nonkeratinied to keratinized (orthokeratinized)
Gingiva → parakeratinized (wet keratin → tougher because food can be abrasive)
*In general skin has orthokeratin
What is the general structure of the tongue?
(classify the epithelium)
Mass of striated skeletal muscle covered by a layer of oral mucosa:
- Mucosa = nonkeratinized (partially keratinized) stratified squamous epithelium
- Lamina propria is strongly attached to the muscles
- Muscle fibers are seen in all different planes of section
- Dorsal surface is irreghular due to presence of papillae
What are the 3 types of papillae found on the tongue?
- Filiform papilla
- Fungiform papilla
- Circumvallate papilla
What are the characteristics/structure of the gingiva?
Where to the oral mucosa and gingiva meet?
Gingiva has stratum germinativum + stratum spinosum → flattens and becomes keratinized (cells don’t die) → retain nucleus until they desquamate Stains eosinophilic
- parakeratinized
- submucosa CT of gingiva and hard palate is directly continuous with periosteum lining the alveolar bone (doesn’t move freely over the bone)
Oral mucosa and gingiva meet at invisible line called the mucoginginval junction
Which 5 tastes are detected by the taste buds?
Sweet, bitter, umami, sour, salt
*All taste buds detect all tastes
What characterizes the filiform papillae?
- Most numerous
- keratinized on the tip
- conical shape
What characterizes fungiform papillae?
- small red dots (appear red because the capillaries come very close to surface)
- more numerous on sides and tip of the tongue
- small mushroom shaped
- not keratinized
What characterizes Foliate papillae?
- Mostly in posterolateral portions of the tongue
- taste buds only present in newbrorn
- These papillae degenerate very fast, not found in adults
- Von Ebner’s gland empty into. the base of the furrow
*No need to identify
What characterizes Circumvallate papillae?
- 8-12 of them form the lingual V (separates anterior 2/3 from posterior 1/3)
- Large structures surrounded by deep crypts
- Small particles dissolved by saliva enter lateral walls/cryps → numerous taste buds in the epithelium
- Von Ebner Gland found are the bottom of each groove/wall → produce aqueous secretion to flush food particles and allow other ones to come in (replace fluid in the crypts)
What are the charactieristics of Von Ebner Glands?
*Minor salivary glands
- Serous acini
- Secretion of lipase
- Active in the stomach
*In the circumvallate papillae, they allow to flush food particles from the grooves to allow new tastes to be detected
Which cells are found in taste buds?
1 taste bud = 1 pore + 50-60 cells
- Basal cells → Type IV (shorter, stem cells)
- Sensory (pale) cells → Type II most abundant
- Supporting (dark) cells → Type I
- Type III (intermediate) cells
*Nonkeratinized epithelium has small openings (pores)
→ Life-span of 7-10d for all → basal cells divide to give rise to new cells
→ Sensory cells (II) have microvilli (neuroepithelial cells) and depolarize when in contact with food → AP through afferent fibers → many synapse onto 1 Schwann cell
Where do humans have taste buds?
VS the slides in the lab?
Humans → Palate, Circumvallate papillae, few in the fungiform papillae
In the lab (animal) → no taste bud in the fungiform papillae, but same for the rest