Exam 1 - SI Flashcards
first two pages of Small/Large Intestine Mod 3A is on deck of Upper GI. try to move them here. this deck starts on page 3 of mod 3a.
first two pages of Small/Large Intestine Mod 3A is on deck of Upper GI. try to move them here. this deck starts on page 3 of mod 3a.
Where does the Jejunum and Ileum begin and end?
Begin at Ligament of Treitz and end at Ileocecal Valve
What is the function of Jejunum and Ileum?
Continued digestion and absorption. Secretion of brush border enzymes to help in digestion and absorption.
What assists with digestion and absorption in the Jejunum and Ileum?
Secretion of brush border enzymes to help in digestion and absorption.
What five things does the Jejunum have a major role in absorping?
Fat, carbs, protein, water, electrolytes
Which vitamin and other three things does the Ileum have a major role in absorping?
VitB12, bile salts, remaining digested nutrients, and water
What is the function unit of the Small Intestine?
Villi
What happens at the Villi?
Site of absorption and secretion in the SI
What do the Villi cover?
Musocal folds which physically slow passage of food
What is the role of the Mucosal Folds in the Jejunum and Ileum? What covers the folds?
Physically slows down passage of food in Jejunum and Ileum. Covered by Villi.
What two cells make up the Villi?
Goblet Cells and Absorptive Columnar Cells
What do the Goblet Cells in the Villi secrete?
Mucus
What happens at the Absorptive Columnar Cells of the Villi?
Site of actual absorption
What are located on each end of the Absorptive Columnar Cells of the Vili?
Microvili
What do Microvili form?
Forms brush border of mucosal surface
What forms the Brush Border of the mucosal surace?
Microvili
What is found along surface of brush border?
Thin layer of fluid
What is the function of the brush border’s thin layer of fluid?
Facilitates absorption of all substances except water/electrolytes
What “extends” into each layer?
Lamina Propria Layer
What are the names of the two arterioles contained in the Lamina Propria Layer, a part of the Villi?
Lacteal and Central Arteriole
What is the function of the Central Arteriole? What does it carry?
(Part of the Lamina Propria Layer of the Villi).
Capillary transport of substances directly to liver via hepatic portal vein. Carries carbs, proteins, and some fats (glycerol and FFA) to liver.
What is the function of the Lacteal Arteriole?
(Part of the Lamina Propria Layer of the Villi).
Transport fat molecules/substances to systemic circulation via Thoracic Duct
What is found at the base of the Villi?
Crypts of Lieburkuhn
What are three cells which made up the Crypts of Lieburkuhn?
Precursor Cells, Paneth Cells, Secretory Cells
What is the function of the Precursor Cells of the Crypts of Lieburkuhn?
Turn over intestinal cells over 4-7 days
What is the function of the Paneth Cells of the Crypts of Lieburkuhn?
Immune function, secretes antibiotic peptides
What is the function of the Secretory Cells of Crypts of Lieburkuhn?
Secrete brush border digestive enzymes
What is the average transit time for the Small Intestine?
1-3 hours, but wide range
Which hormones stimulate the Small Intestine?
Secretin, CCK, intestinal gastrin, motilin
What are the three motility patterns of the SI?
Segmentation, Peristalsis, MMC