2A-A&P of the STOMACH Flashcards
What are the 4 main regions of the stomach? (in order of proximal to distal)
Cardia–>Fundus–>Body–>Pylorus(Antrum&Canal)
What are the two sphincters of the stomach?
the LES and the Pyloric
What are the three layers of the muscularis externa in the stomach? FROM OUTERMOST to Innermost
1.Outermost Longitudinal 2.Middle Circular 3. Innermost Oblique*unique to stomach!
Which omentum is on the rostral(head) portion of the stomach?
Lesser Omentum (think space!)
Which omentum is on the caudal (tail) part of the stomach?
Greater Omentum
What is the name for the layer of alkaline mucus?
Gastric Mucosal Barrier
KEY TO DRUG understanding: What molecules play an important role in protecting the stomach mucosa from injury by enhancing mucus production?
PROSTAGLANDINS-Using NSAIDs block prostaglandin production and can cause weakening of the mucosal layer
What are the LARGE hills and valleys of the stomach walls?
RUGAE
What are the millions of deep channels on the rugae of the stomach wall?
Gastric Pits
The mucosal surface of the stomach is a ___________ epithelium.
Simple Columnar
What are the specialized cells of the gastric pits?
Gastric Glands
What is the average lifespan of a stomach cell?
2-3 Days
What are the stem cells of the stomach?
Regenerative Cells-they can turn into any cell
HAHA what are the cells that line the surface of the gastric mucosa?
Surface Lining Cells
Which cells secrete alkaline mucus?
Mucus Neck Cells
Which cells secrete HCl & Intrinsic Factor?
Parietal Cells
What are the two main functions of Intrinsic Factor?
Absorption and ErythroPoesis
Which cells secrete pepsinogen and Gastric Lipase?
Chief Cells
Which cells secrete Gastrin (G cells) & Histamine (ECL cells)?
Endocrine Cells
What is another name for a Parietal Cell?
OX-IN-TIC (oxyntic)
What is another name for a Chief cell?
ZY-MO-GENIC
What is another name for an endocrine cell?
EnteroEndocrine Cell
Review from earlier…How much Gastric Juice is produced daily?
2.5L…BOOM
The _____ junctions between the cells are also part of the mucosal barrier that protects the gastric epithelium from damage.
Tight
What are the four examples of substances that can disrupt the mucus layer?
Ethanol, Bile Salts, NSAIDs, and H. Pylori
What hormone and cell stimulates parietal cells to produce IF and HCl?
Gastrin from Endocrine Cells (G cells)
How much bolus can the stomach hold?
3-6 L of Crap!
What is the creamy,soupy paste produced by the stomach?
Chyme
Do the Proton Pumps of a Parietal Cell require ATP?
YES! Pumping H+ against its [Gradient]
What is the end result in the blood of HCl production in the stomach? So what can happen to the pH of blood after a meal?
An Alkaline Tide, BiCarb is released into the blood while H+ is released into the stomach (same as blood buffer equation)…pH can Increase after a meal
What are the three phases of Gastric Secretion and Motility?
1.Cephalic Phase 2.Gastric Phase 3.Intestinal Phase
Which phase is preparatory? Which CN is stimulating the prep?
Cephalic Phase, VAGUS stimulates gastric juice production and therefore more gastrin and gastric juice
Which phase begins when food reaches the stomach?
Gastric Phase
What is the positive feedback loop caused when the stomach is distended with food?
Gastrin release to stimulate the Parietal cells to release more gastric juices
Which hormone increases levels of HCl secretion from parietal cells?
HISTAMINE
What converts Pepsinogen to Pepsin?
HCl
What are the three hormones that inhibit gastric juice secretion in Intestinal Phase?
1.CCK (“Cole-E-sis-TA-K-eye-NIN”) 2. Secretin 3.Gastric Inhibitory Peptide
What are the two functions of GIP (Gastric Inhibitory Peptide)?
1.Stop Gastric Juice Production 2.Inhibit Gastric Motility
What are the three things that can stimulate H+ production in a Paritetal Cell?
- Histamine 2.Gastrin 3.Vagus Nerve-Acetylcohline
What type of receptor does Histamine work on in Parietal cells?
H2
What is the reflex when products of protein digestion and H+ in the duodenum inhibit vagus nerve activity? Which phase?
EnteroGastric Reflex (Intestinal Phase)
Is there absorption of nutrients in the stomach?
NOPE