Upper GI II Flashcards
________ opens into bottom of gastic pit
Narrow isthmus
______ of the gastric gland extends into the lamina propria
Fundus (base)
Cells of the gastric gland
- mucous neck cells
- Stem cells in neck
- Chief cells (zymogenic cells)
- Parietal cells (oxyntic cells)
- Enteroendocrine Cells (APUD cells)
Mucous neck cells of the gastric glands secrete
soluble mucous
Chief cells (zymogenic cells) secrete
Pepsinogen
Parietal cells (oxyntic cells) manufacture _______ and secrete ______
Manufacture HCl (note that they secrete H+ and Cl-) They secrete intrinsic factor
Enteroendocrine cells (APUD cells) function of gastric glands
- secrete hormones
- Amine Precursor uptake and decarboxylation
Parietal cells are unique cell of the
gastric gland
Histological characteristics of parietal cells
Large pyramidal shaped, eosinophilic cell
Parietal cells produce ______ and secrete ____-
Produce HCl
Secrete intrinsic factor
Parietal cells generate hydrogen ion from _______ similar to osteoclast
carbonic acid
Parietal cells have prominent __________ lined by ______
Parietal cells have a prominent intracellular canaliculi lined by microvilli
_________ of the parietal cells are part of exocytosis-endocytosis funciton
Turbulovesicle pools
Function of gastric intrinsic factor secreted by parietal cells
necessary for absorption of Vitamin B12 by the ileum
Chief cells secrete
pepsinogen
small cells of gastric glands with secretory vesicles polarized toward basal surface in proximity to blood vessels
Enteroendocrine (APUD cell)
The enteroendocrine cell (APUD cell) produce
peptide hormone and serotonin
What increases surface area of the Intestines
= Length of small and large intestine
- Plicae circulares (valves of Kreckring)
- Villi
- Microvilli
What are the 3 levels of folding in the small intestine that increase surface area
- Plicae
- Crypt-Villus System
- Microvilli
These are folds of the mucosa, each with a submucosal core
Plicae
Each villus contains a core of
lamina propria
The crypts extend down between the _____ below the
Villi, below the bases of the villi
Crypts and villi constitute _______ of the small intestine
glands
Wall of villus is composed of ________ epithelium with _______
simple columnar epithelium with goblet cells
Each villus contains a blind-ending lymphatic referred to as a
lacteal
Each villus contains a ______ plexus
Capillary plexus
Each villus contains
- A core of lamina propria
- A capillary plexus
- a blind-ending lymphatic referred to as a lacteal
Microvilli are covered with ______ and _______
Glycoprotein and glycocalyx (glycolipid coat)
Glycocalyx (glycolipid coat of microvilli) contains an array of ________ enzymes . Name them? and who produces them
Brush-boarder enzymes
- Maltase
- Sucrase
- Isomaltase
- Lactase
- Lipase
- Peptidases
- Produced by small intestinal epithelial cells
Gastric glands are simple ______ ______ glands
Gastric glands are simple branched tubular glands
Bundles of actin filaments within microvillus are covered by a
formin cap
The actin filaments of a microvillus are tied to terminal web intermediate filaments (cytokeratins) via
spectrin fibrils
Microvilli are supported by
actin microfilaments
Actin filaments of microvilli are tied to ________ via spectrin fibrils
Terminal web intermediate filaments (cytokeratins)
Actin filaments of microvilli are bound to plasma membrane covering villus via membrane-linking proteins____ and ____
- Myosin I
- Calmodulin
Actin filaments of microvilli are bound to each other via actin cross-linking proteins _____ and _____
villin and fimbrin
