1. What are the most important functions of the stomach?
Storage of food
Mixing of food with gastric secretions to form chyme
Slow emptying of the chyme into the SI at a suitable rate
Absorption: ASA, alcohol
HCl damages duodenum and bile damages gastric mucosa
2. Outline the cellular mechanisms involved in causing the disturbance in acid-base balance.
The stomach secretes acid which is ultimately derived from water. It's pumped across the
lumenal membrane coupled with Cl-. For every H+ pumped into the stomach, an HCO3 is
pumped into the plasma producing an alkaline tide. This tide is balanced by an acid tide from the
pancrease and liver. The balance is upset post-gastrectomy; the acid tide is greater and metabolic
3. How does the anemia relate to the partial gastrectomy? Expand on the role of the stomach
in the absorption of minreals and vitamins
Oxyntic cells release intrinsic factor which is vital for vitamin B12 absorption in ileum.
In the patient, the upper part of the stomach was removed so many oxyntic cells were
lost. Pernicious anemia (characterized by immature macrocytic RBCs) results 2 years
later. The body has about 2 years worth of B12 in storage.
The acid in the stomach converts ferric iron into the ferrous iron (Fe2+), the only
absorbable form of non-heme iron that is absorbed via gastroferrin in the ileum. This can
occur from the removal of the antrum and therefore G cells (main stimulant of acid
secretion). Characterized by microcytosis (small red blood corpuscles). Occurs within a
4. How would the composition of gastric secretions be affected in this patient after the
gastrectomy? Expand on the different secretory cell types found in the gastric mucosa.
Gastric juice (2L/day)
Parietal juice (Acid)
Alkaline juice (mucous cells)forms a protective barrier that lines the stomach. Blocks
pepsin Production of gastric juice isotonic with plasma
Type of cell Location Secretion
G cell Antrum of stomach Gastrin
ECL cell Pyloric region