Download Midterm

Midterm
• Nov. 8th
• Content, ch. 8, 9, 10, 11, 13, 14, 15.
• Muscle, Nervous Tissue, Blood, Circulatory
system, endocrine system, integument,
respiratory system (not digestive system)
We have talked about the mucosa
in the fundic region
• The gastric pits
• The fundic glands
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Mucus neck cells
Oxyntic cells
Zymogenic cells
DNES cells
Parietal cells
• HCl and gastric intrinsic factor which is a
glycoprotein secreted to the stomach lumen to
absorb vitamin B12.
• Intracellular canaliculi lined by microvilli
• Lots of H+/K+ ATPase
• Carbonic anhydrase makes H2CO3H+H+
leaves K+ entersK leaves through K+ channel
and starts the pump again
DNES cells
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Along G-I tract see chart on pg 390
Enteroendocrine cells
Endocrine, paracrine, hormones
Substances same as those released by
neurons
• Sit on basal lamina
DNES cells
• Some reach the lumen (open type), narrow
microvillar apex may repond to what is in
the lumen
• Some don’t (closed type)
• Vesicles secrete into lamina propria
• Paracrine effect for some
• Endocrine effects for some
DNES cells stomach
• Glucagon (enterglucagon) stimulates
hepatocyte glycogenolysis
• Somatostatin inhibits release from
neighboring DNES cells
• Serotonin increaes peristaltic movement
• Substance P increases peristaltic movement
DNES cells stomach
• Histamine stimulates HCL secretion
• Gastrin – stim. HCl secretion, gastric
motility, esp. contraction of pyloric region
and relaxation of pyloric sphinctor,
proliferation of regenerative cells in the
stomach body
• Glecentin stimulates hepatocyte
glycogenolysis
Muscularis mucosae stomach
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3 layers
Inner cirucular
Outer longitudinal
Outermost circular
Mucosal differences between
cardiac and pyloric regions
• Cardiac region:
– shallow gastric pits,
– base of glands are very coiled.
– Cardiac glands suface-lining cells, some
mucous neck cells, parietal cells, few DNES
cells, no chief cells
Mucosal differences between
cardiac and pyloric regions
• Pyloric region
– Same cell types as in cardiac region
– Predominant is mucous neck cell and these also
secrete lysozyme
– Glands are branching
– Deep gastric pits, halfway into the lamina
propria
Stomach submucosa
• Rich vascular and lymphatic network
• Cells of CT proper
• Submucosal plexus, within the submucosa
in the vicinity of the muscularis externa
Muscularis externa of the
stomach
• Innermost oblique layer
• Middle circular layer
• Outer longitudinal layer
• Serosa invests entire stomach
Small intestine
• Duodenum, jejunum, ileum
• Common histology: increase surface
absorptive and digestive area by
– Plicae circularis
– Villi
– microvilli
Small intestine: mucosa
• Epithelium
– Surface absorptive cells with brush border, mv,
glycocalyx
– Goblet cells
– Microfold cells where lympoid cells are close
to the epithelium
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Small intestine: mucosa
• Lamina propria, core of villi with LCT
– Also extends to the muscularis mucosae
• bv and lv,
• Tubular intestinal glands, the crypts of Lieberkuhn
• Lymphoid cells
crypts of Lieberkuhn
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Simple tubular and branched tubular glands
Open into intervillar spaces
Surface absorptive cells
Goblet cells
Regenerative cells
DNES cells
Paneth cells
DNES cells of the crypts of
Lieberkuhn
• Glicentin stimulate glycogenlysis in
hepatocytes
• Cholcystokinin stimulates release of
pancreatic enzymes, gall bladder
contraction
• Gastric inhibitory peptide inhibits HCl
secretion
DNES cells of the small intestine
• Motilin increases intestinal peristalsis
• Neurotensin increases blood flow to ileum
and decreases peristaltis of large and small
intestines
• Pancreatic polypeptide, unknown fn