GI Anatomy Flashcards
What provides the parasympathetic innervation for the foregut, midgut and hindgut?
F: vagus nerve.
M: vagus nerve.
H: pelvic splanchnic nerves (S2,3,4).
What marks the separation between foregut and midgut?
The entrance of the bile duct at the major duodenal papilla.
What provides the sympathetic innervation of the foregut, midgut, and hindgut?
F: T5 - T9.
M: T10 - T12.
H: L1 - L3.
What vessels supply the foregut, midgut, and hindgut?
F: celiac trunk.
M: superior mesenteric artery.
H: inferior mesenteric artery.
What are the 3 esophageal constrictions and at what approximate spinal level are they located?
(1) cervical (C6)
(2) thoracic (T4)
(3) diaphragmatic (T11)
What portion of the esophagus contains skeletal muscle in the muscularis propia?
The upper 5% has skeletal muscle exclusively. The middle 45% has a mixture of skeletal and smooth.
What volume of food can the stomach typically hold?
2-3 L.
What are the glandular divisions of the stomach? The anatomy divisions?
Glandular: cardiac, fundus, pylorus.
Anatomic: cardiac, fundus, body, pylorus.
What are the folds in the stomach called?
Rugae.
What marks the squamo-columnar junction between the esophagus and stomach?
The Z line.
What vessels branch from the celiac trunk?
(1) common hepatic artery.
(2) left gastric artery.
(3) splenic artery.
What vessels supply the lesser curvature of the stomach? The greater curvature?
Lesser: left and right gastric arteries.
Greater: short gastric arteries and the left and right gastroepiploic arteries.
Which portion of the gut tube has more than 2 layers in the muscularis propia?
The stomach, which has an innermost oblique layer.
Which vessels supply the jejunum?
The simple arcades and the long vasa recta.
Which vessels supply the ileum?
The complex arcades and the short vasa recta.
What vessels supply the ascending colon?
The iliocolic and right colic arteries.
What vessels supply the transverse colon?
The middle colic artery.
What vessels supply the descending colon?
The left colic artery.
What vessels supply the sigmoid colon?
The sigmoid arteries branching off of the left colic and superior rectal arteries.
How are the longitudinal muscles of the large intestine arranged?
As 3 strips of muscle called teniae coli.
What are the layers of hollow GI organs, from innermost to outer?
Surface epithelium, lamina propia, muscularis mucosae, submucosa, muscularis propia (2-3 layers), adventitia or serosa.
What type of epithelium is found in the esophagus? What is its purpose?
The epithelium is stratified squamous. It’s role is largely just as a conduit for food; there is no absorption and no significant secretion.
What type of epithelium is found in the stomach?
The epithelium is glandular. The purpose is secretory, exposing food to acid and proteolytic enzymes. There is no absorption.
J: This term is used to describe mucosa that is acid-producing.
What is oxyntic?
What parietal cells?
Cells within the gastric pits of the corpus, with pink cytoplasm on H&E. They produce hydrochloric acid.
What are gastric chief cells?
A type of cell within gastric pits of the corpus. They secrete enzymes, like pepsinogen, gastric lipase, and rennin.
Which cells secrete gastrin?
G cells in the antrum of the stomach.
What are gastric foveolar cells?
Epithelial cells that secrete mucous.
What epithelial cells predominate in the cardia of the stomach?
Foveolar cells.
What are the effects of gastrin?
Directly and indirectly promotes acid secretion: (1) direct stimulation of parietal cells, (2) stimulation of enterochromaffin-like cells to release histamine, which also acts on parietal cells.
What nerve plexuses are found throughout the GI tract?
The submucosal plexus and the myenteric plexus within the layers of muscularis propia.
What types of cells predominate in the epithelium of the gastric antrum?
Foveolar cells and G cells.
How is the surface area of the small intestines increased?
Through the formation of plicae, villi, crypts, and microvilli.
What are lacteals?
They are lymphatic vessels within the lamina propia in the small intestine, involved in the absorption of dietary lipids.
What are Paneth cells?
Epithelial cells in the crypts of the small intestine that are involved in the digestion and destruction of intestinal microorganisms.
What are Brunner glands?
Glands found in the duodenum that produce a mucous-like secretion containing bicarbonate. They serve to protect against gastric acid and to activate digestive enzymes through alkalization.
What is the function of the colon?
(1) Absorption of water, Na+, and Cl-.
(2) Secretion of mucus and bicarbonate.
What stimulates goblet cells in the colon to secret mucus?
Tactile stimulation.
What is MALT?
Mucosa-associated lymphoid tissue which can be found in the small and large intestine.
What are M cells?
Mucosal epithelial cells in the intestines that absorb, transport, process and present antigens to subepithelial lymphoid cells.
What antibodies are most frequently produced by B cells in Peyer’s patches?
IgA and IgM.
