Digestive Flashcards
(28 cards)
The mucosa of the gut is made of what 3 layers? and the function of each?
- mostly columnar epithelium, stratified squamous in esophagus and anal canal.
- Lamina propia: contains fibers, lymph nodes and immune cells
- muscularis mucosa: facilitate blood flow within the mucosa.
submucosa of gut contains blood vessels, meissener plexus of nerves and lymphatics . what is the function of region?
elasticity permits the folding of the mucous membrane in the empty state and smoothing out during the passage of food
Muscularis externa contains myenteric plexus between two smooth muscle layers. What is the function?
facilitates the mixing and propagation of ingested food
How is the lamina propia in esophagus different than in the gut?
not cellular b/c thick epithelium. however lymph nodes are found near glandular ducts. (lower portion of organ)
which layer are esophageal glands found?
submucosa
what is significant about the muscularis externa of the esophagus
the presence of striated skeletal muscle in the upper 1/3 of esophagus—middle third contains a mixture of skeletal and smooth muscle—lower third contains smooth muscle only
cilatated columnar epithelium in stomach secretes:
potassium, prostaglandins, mucus and bicarbonate to protect gastric mucosa.
What are the 4 cell types of fundic glands
Mucous neck cells Parietal (oxyntic) cells Chief (zymogenic, peptic) cells Gastroentero-pancreatic (GEP) endocrine cells Stem cells
Shape and location of parietal (oxyntic) cells
centrally located nucleus—pale staining cytoplasm—pyramidal shaped cell—concentrated in upper half of the gland
parietal (oxyntic) cells
HCl helps activate pepsinogen and kills bacteria.
-gastrin intrinsic factor binds B12 which is necessary for absorption of B12 in small intestine
Prilosec (omeprazole)
drug for ulcers—inhibits H+, K+ ATPase pumps in parietal cells
Chief (zymogenic, peptic) cells
location and structure.
pyramidal shaped cell—located in lowest portion of gland—cytoplasm stains more darkly than parietal cells
what is the function of Chief (zymogenic, peptic) cells
Secretes pepsinogen, precursors of rennin and lipase
What regions of GI does absorption occur?
mainly small intestine, then stomach and large intestine
Masticatory mucosa contains what type of epithelium and give example of those regions.
- keratinized stratified squamous epithelium (may have parakeratinized mixed in with keratinized)
- hard palate, and gingivae
Specialized mucosa in oral cavity contains what type of epithelium and give example of those regions?
- keratinized and nonkeratinized stratified squamous epithelium with papillae
- Dorsal surface of tongue, soft palate, and regions of the pharynx
what is the vermillion zone?
-Abrupt change in epithelium from that of the skin—keratinized or parakeratinized stratified squamous epithelium—thicker than outer lip but with many sensory papillae
what is the labial gland located and function?
submucosa—moisten inner surface of lip
What type of epithelium of the hard palate and purpose of the lamina propia structure?
Keratinized and parakeratinized stratified squamous epithelium.
-mucosa does not move and is protected from tearing
What is the transition epithelium from lower to upper of soft palate.
nonkeratinized stratified squamous epithelium to pseudostratified ciliated columnar epithelium in the nasal aspect of the palate. boundary is variable
describe the secretory system of salivary glands
serous, mucous, or mixture of both cells arranged into acini—acini are surrounded by myoepithelial cells that contract to squeeze the secretion from the secretory portion into the duct system.
What are the functions of saliva
- facilitates swallowing and phonation
- amylase secretion
- dissolve food
- buffered with bicarbonate
- consist of lysozymes (IgA)
What is the term that separates the interior and superior tongue?
sulcus terminalis
What is the function and epithelium of filiform papillae
Keratinized stratified squamous epithelium—no taste buds
—main function is to help with chewing and mixing of food
