small intestine dr iramtassaduq. small intestine dr iramtassaduq
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SMALL INTESTINE Dr IramTassaduqTRANSCRIPT
SMALL INTESTINE Dr IramTassaduq SMALL INTESTINE The small
intestine is divided duodenum jejunum ileum. THE DUODENUM The
duodenum is the first section of the small intestine and has a
thicker layer of tissue than the other areas of the small
intestine. It neutralizes stomach acids and breaks down
carbohydrates and fats. The duodenum is about 2 feet long. JEJUNUM
The jejunum is the main section of the small intestine. It covers
about 15 feet and is responsible for the absorption of almost all
nutrients except water. ILEUM The ileum is the last section of the
small intestine and spans about 6 feet. Its function is to absorb
water and vitamins. PLICAE CIRCULARES (valves of Kerkering) are
macroscopically visible, crescent-shaped folds of the mucosa and
submucosa. permanent structures, i.e. their presence does not
depend on the state of distension of the small intestine. are
absent from the first few centimetres of the duodenum and the
distal part of the ileum. well developed in the jejunum. increase
the surface area of the mucosa MUCOSA INTESTINAL VILLI The entire
intestinal mucosa forms intestinal villi (about one mm long), which
increase the surface area by a factor often. The surface of the
villi is formed by a simple columnar epithelium. MICROVILLI
INTESTINAL GLANDS INTESTINAL CELLS ENTEROCYTES GOBLET CELL GOBLET
CELLS The apical end of each goblet cell is occupied by a large
mass of mucus, which compresses adjacent cells. The nucleus toward
the basal end of the cell. Attached by junctional complexes
(evidenced in light microscopy as the "terminal bar") to adjacent
absorptive cells . PANETH CELLS Paneth cells are secretory
epithelial cells located at the ends of intestinal crypts. The
function for these cells is secretion of anti-bacterial proteins
into the crypt lumen, thereby providing protection for the stem
cells which line the crypt walls. PANETH CELLS Paneth cells have
typical serous-secretory appearance, with basophilic basal
cytoplasm (containing protein-synthetic rough endoplasmic
reticulum) and apical secretory vesicles (zymogen granules).
ENTEROENDOCRINE CELLS ENTEROENDOCRINE CELLS
Concentrated in lower portionof intestinal gland Produce a lot of
peptide hormones COMPARISON Thank you