S4 L1 The Stomach Flashcards
Functions of the stomach
- What is the stomach?
- 4 functions
- Role of chyme
Anatomy of the stomach
- 3 ‘sections’
- 2 sphincters
- What is the sphincter composed of?
Receptive relaxation
- What is this? How does it work?
- What mechanisms stop stomach pressure increasing a lot when it is filled?
- Distinct muscles in the diaphragm
- Role of angle of entry
Muscles of the stomach:
- Number of layers
- Reason for this
- Describing thickness of the walls of the stomach
- Reason for the different thicknesses:
Surface of the stomach:
- 3 main ‘parts’ of the epithelium and their role: Surface mucous cells, gastric pits, gastric glands
- Gastric glands anatomy (3 cells)
- What do the three cell types do/role?
- Which part of the stomach are each cell type ‘more in’
Protective mechanisms:
- Against what…?
- 4 protective mechanism, list and explain
What are parietal cells? and there role (brief)
Epithelial cells in the stomach
Responsible for gastric acid secretion
Control of acid secretion:
- How do parietal cells produce acid in the stomach? (particularly pump)…
Parietal cells: How is acid secretions controlled?
- Two phases
- Two main ‘parts’ of the parietal cell necessary for it’s function
- What happens once the process is stimulated…
What stimulates acid production?
- Before ingesting something… ____ triggers, phase of digestion, how much this accounts for acid production
- Once ingesting something… ____ triggers, phase of digestion, how much this accounts for acid production
What stimulates a partietal cell?
- 3 receptors
Gastrin stimulation:
- Role of gastrin
- Which cells release gastrin? ____
- ___ (these cells), are stimulated by….
- These cells produce ____
- What does this hormone do? Where does it go? What receptor does it bind to and on which cell?
Stimulates acid production
- What other way can G cells be stimualted?
- How does this happen (brief ‘process/pathway’)
stomach stretching, sensory triggers cause vagal stimulation, vagus nerve can stimulate G cells via acetylcoholine and muscarinic receptors
Histamine stimulation:
- What cell produces histamine?
- How is this cell stimulated to produce histamine?
- Role of histamine?
G cells NOT C cells in the pic
How is acid secretion inhibited?
- What happens when the stomach begins to empty?
- Which hormone is important for acid secretion inhibition?
- Which cell secretes this hormone?
- How is this hormone secreted?
- How does this hormone go on to inhibit acid secretion?
How is HCL produced in the parietal cell?
- Channels/pumps on the apical membrane
- Channels/pumps on the basolateral membrane
- Explainin this system
- What is a the alkaline tide
