Ch24- Stomach Anatomy ALL
organ storage tank, mechanical breakdown of food
organ chemical digestion of proteins by acids and enzymes
organ production of intrinsic factor
organ digesta exits as chyme; viscous acidic fluid
mucus from this protects esophagus in stomach
Fundus and Body
location for gastric secretion of acids and enzymes in stomach (2)
mixing tank in stomach
this regulates release of chyme in stomach
this structure of stomach contains mucous and gastrin secretion in stomach
muscle allows expansion in stomach
liquid product of digestion, acidic fluid
stomach daily gastric juice amount
parietal cells of stomach secrete
chief cells of stomach secrete
enteroendocrine G cells (hormones) secrete
what type of cell is enteroendocrine G cells in stomach?
Simple columnar epithelium
tissue composed of goblet cells in stomach secrete alkaline (base) mucus
Alkaline (base) Mucus
goblet cells in stomach secrete
Gastric pits; goblet cells
simple columnar ET in stomach is surround by __ ___ filled with ____ ___
storage tank, mechanical breakdown, chemical digestion, intrinsic factor production, digesta leaves as chyme
stomach mechanisms (5)
A glycoprotein by the mucosa of the stomach and intestines that is essential for the absorption of vitamin B12.
substance need for vitamin B12 absorption
hormone that stimulates activity of gastric glands
Parietal and Chief
gastric glands are dominated by these 2 types of cells that form gastric juice..
destruction by chemical action
epithelial cells of the stomach form
HCL and Water
plasma membrane of stomach is impermeable to (2)
these cell are know as quick replacement cell of damaged epithelial
layer protects stomach against self digestion and corrosion
Mucus Neck, Parietal, Chief, Enteroendocrine (G-cells)
secretory cells of stomach (4)
kills microorganism, denatures proteins and inactivates enzyme
breaks down plant cell wall and CT in meat
digestive enzyme that activates pepsin
stimulates secretion of parietal and chief cells
pepsin is most effective at what pH level?
hormone that inhibits release of gastrin
Salivary Amylase (parotid)
enzyme break down CHO, include gland
enzyme break down lipids, include gland
what doesnt the stomach absorb?
the stomach is ___ to water
what type of food does the stomach start chemical digestion?
the neural or electrical arousal of an organ or muscle or gland
cephalic, gastric, intestinal
3 overlapping phases of stomach controlled by nervous innervation and hormone
phase begins at sight, smell, taste, and thought of food
this nerve activates submucosal plexus
this nerve plexus stimulates mucous cells, chief, parietal, and g cells
Mucous, Chief, Parietal, G cells
the submucosal plexus stimulates which secretory cells of the stomach?
this phase is controlled by nervous innervation and hormones
the cephalic phase is controlled by what plexus?
Distention, increase pH, partly digested protein, histamine effects
the gastric phase is initaited by what? (4)
act of expanding
Stretch repectors and Release of Histamine
what is stimulates when the stomach distends? (2) (gastric phase)
release of histamine in the stomach stimulates what?
presence of histamine cause the stomach to do what?
presence of partly digeted proteins stimulate what enzyme secretion?
an increase in pH signals what receptor response? (gastric phase)
histamine is stored in what layer of the stomach?
cell binds to receptor on partietal cells and stimulates HCL acid secretion
pepsinogen (hormone form)
phase begins when chyme first enters the small intestine
phase controls rate of gastric emptying by temporary inhibition
during this phase the duodenal distented and inhibits gastric contraction (neural response_
during the intestinal phase the neural responce promotes this contraction (stomach part)
CCK & GIP
Lipids and CHO during intestinal phase stimulate what? (2)
hormone that small intestine secretes to stimulate pancreas to release pancreatic juice
Drop in pH stimulates what?
Gastric Inhibitory Peptide
hormone inhibits gastric secretion of *acid and enzymes*
hormone inhibits gastric secretion and *reduces rate and force of gastric contractions*
hormone secrected in duodenum inhibits parietal cells and chief cells in stomach
how long is the small instestine?
how much absorption occurs in the small intestine?
this part of small intestine is .25m long and sits in the reptroperitoneal cavity
part of small intesine precieve pancreatic juice and bile - "mixing bowl"
part of small intestine 2.5 m long and has the largest suface area
region of small intestine wher most of chemical digest and nutreint is absorpbed
part of small intestine is 3.5 m long
part of small intestine contains peyer patches
gland that secrete juice ~1.5 L day
protects stomach against self digestion and corrosion
organ; secretes digestive enzyme and expands
type of digestion where protein are broken down with HCL and pepsin
enzyme breaks apart proteins effect pH 1.5-2
controlled by nervous innervation and hormones
smell, taste the though to food
pepsinogen (hormone form)
stomach distention phase
stimulates stretch receptors
Increase in pH
controls rate of gastric emptying by temporary inhibition
duodenal distension inhibits gastric contraction
enzymes (carbohydrase, protesase, lipase) and bicarbonate (keeps pH low in SI) form this
parietal and chief cells form this acidic juice
intrinsic factor in SI is secreted by
Mucous, Chief, Parietal, G Cells
Submucosal plexus in the cephalic phase actives these 4 secretory cells
Parietal and Chief
g cells (gastrin) further stimulate these cells
the submucosal plexus in the cephalic phase is activated by what major nerve
what major nerve is activated by the CNS in the cephalic phase
the vagus nerve in the cephalic phase activates what nerve?
glands in _____ region of the stomach secrete mucus and important digestive hormones including gastrin
the nerual response for this phase inhibits gastric contraction as duodenal distends then promotes pyloric contract
distention of the stomach stimulates stretch receptors and histamine release during this phase
*local effect* of histamine stimulate
-Presence of partly digested proteins
-Local effect of histamine stimulate parietal cells
histamine in the stomach is stored in this layer
protein digestion in the stomach is ___.
Salivary Amylase and Lingual Lipase
CHO and lipids permits limited digestion in the stomach by
Nutrient absorption, Transport Mechanism, Impermeable to water
what does the stomach not do or have
is digestion complete in the stomach?