GI Tract Flashcards
What are the 4 layers of the GI tract?
Mucosa, Submucosa, Muscularis Externa, Serosa or Adventitia
What is the function of the Mucosa
Protection
Absorption
Secretion
What is the function of the Submucosa?
In the duodenum and esophagus, it has glands
In its the periphery, the Meyenteric plexus is found
What is the purpose of the Muscularis externa?
To mix and propel intestinal contents
What does the mucosa consist of? the functions?
Lamina propria (loose connective tissue that contains blood and lymphatic vessels+tissues, connective tissue cells, and wandering cells in connective tissues such as plasma cells and eosinophils),
Epithelium,
Muscularis mucosae (smooth muscle that produces movement of mucosa creating ridges and valleys that facilitate absorption and secretion)
What kind of tissue is submucosa made of ?
Dense, irregular, connective- containing blood and lymphatic vessels and nerve plexus
Serosa vs. Adventitia. Who wins when?
Serosa when a simple squamous epithelium is present (the mesothelium)
Adventitatia when the part of the digestive tract is fixed directly to the abdominal or pelvic wall.
What are the four types of taste buds and their abundance in man? What cell types are they?
Filiform (none), Fungiform (few), Circumvallate (many), Foliate (many but not seen much in man)
All are stratified squamous except only Filiform is stratified squamous keratinized epithelium. (Taste buds have About 50-100 cells)
Where can tongue murcosal and serous galnds and adipose tissue be found?
in between skeletal muscle bundles
Where can esophageus glands proper be found? with what?
Submucosa of the esophagus along with connective tissues
Where are the esopogeal cardiac glands? What is the distance between them?
at either ends of the esophagus, 10 inches (25cm)
where is the esophageal adventitia and serosa?
above and below the diaphragm respectively.
What are the three major types of gastric mucosal glands?
Cardiac
Gastric or Fundic
Pyloric
What is the name for permanent invaginations into the lamina propria that serve as ducts for mucosal glands?
Gastric Pits
Order in pit length increasing
cardiac, gastric, pyloric
Of the gastric, pyloric, and cardia glands, which coil and which are straight?
Coiled: Cardiac and Pyloric
Straight: Gastric/Fundic