Step 1: Gastric Juice Definition.
Gastric juice is a digestive fluid produced by stomach lining glands, containing hydrochloric acid (HCl), pepsinogen, intrinsic factor, and mucus.
Step 2: Gastric Juice Functions.
- Hydrochloric acid: Establishes an acidic pH for digestion.
- Pepsinogen (activates to pepsin): Aids in protein digestion.
- Intrinsic factor: Essential for Vitamin B12 absorption.
- Mucus: Safeguards the stomach lining from self-digestion.
Step 3: Exclusion of Alternatives.
- (A) Duodenum: Receives bile and pancreatic juice, not gastric juice.
- (C) Kidney: Produces urine, not a digestive fluid.
- (D) Small intestine: Secretes intestinal juice, not gastric juice.
Step 4: Final Determination.
The stomach is the origin of gastric juice.