GI tract- Histology Flashcards
Anterior 2/3rd of the tongue is covered by _ while the posterior 1/3rd of the tongue is covered by _
- Stratified squamous epithelium, with papillae on dorsal surface
- Strat squamous epithelium, mostly lacks papillae except the circumvallate papillae.
4 Types of papillae in the tongue?
- Fungiform
- Circumvallate
- Foliate
- Filiform
4 Major layers of the digestive tract?
- Mucosa: 3 parts
- a. Epithelium: sits on a basal lamina
- b. Lamina Propria: loose connective tissue
- c. Muscularis Mucosae: thin layer of smooth muscle
- Submucosa: loose connective tissue
- Muscularis Externa: two thick layers of smooth muscle, an inner circular layer and an outer longitudinal layer
- Serosa or Adventitia: outer layer of connective tissue that either suspends the digestive tract or attaches it to other organs
Glands are found in the _ layer of the oesophagus.
Submucosa- submucosal glands
The transition from stratified squamous epithelium to columnar epithelium occurs at the _ junction
Gastro-oesophageal
What are gastric pits?
Holes found in the relatively flat surface of the stomach, contains gastric glands within them.
The chief cells and the parietal cells of the gastric glands produce _ and _
- digestive enzyme 2. HCL
What are the 3 regions of the stomach?
- Cardia- deep gastric pits, loosely packed glands
- Body- shallow pits, long straight glands
- Pylorus- Deep pits, coiled glands
The additional layer of the muscularis externa (found in some parts of the stomach) allows the _ action of food.
Churning
The gastroduodenal junction contains a circular layer of thick muscle which forms the _ _.
Pyloric sphincter
The Crypts of Lieberkuhn are found between the bases of adjacent _.
Villi
Compare the contents of the parts of the small intestine
Duodenum: Contains Brunner’s glands in the submucosa.
Jejunum: Tallest villi, located on permanent circular folds of the mucosa and submucosa, the plicae circularis.
Ileum: Characterized by aggregations of lymphoid follicles called Peyer’s patches found in the submucosa and often extending into the lamina propria.
Which type of cells are found in the small bowel? (5)
Enterocytes: principle absorptive cell.
Goblet cells: Produce mucin to protect epithelium and lubricate passage of material.
Paneth cells: they have a defensive function and have a role in regulating bacterial flora (secrete lysozyme and definsins).
Enteroendocrine (Neuroendocrine) cells: Produce hormones that contribute to the control of secretion and motility (e.g. gastrin, cholecystokinin (CCK), vasoactive intestinal peptide (VIP))
Stem cells: Divide to replinish epithelium
The duodenum receives _ from the stomach
Chyme
_ Glands are found within the duodenum
Brunner’s
