Cephalic Phase

Cephalic Phase

Question 1. Cephalic phase of gastric secretion.
Answer:

Cephalic phase:

• Secretion of gastric juice by the stimuli arising from head region is called cephalic phase.
• It occurs even before food enters the stomach.
• Gastric juice secreted during this phase is rich in enzymes and hydrochloric acid.
• About 30-50% of total juice is secreted during this phase.
• It is regulated by conditioned and unconditioned reflex.

Question 2. Functions of stomach.
Answer:

1. Mechanical function:

• Storage function.
• Stomach stores the ingested food and gradually pass it into intestine.
• Formation of chyme.
• The peristaltic movements of stomach mix the bolus with gastric juice and convert it into chyme.

2. Digestive function:

• Enzymes present in the gastric juice of stomach helps in the digestion of various nutritive substances.

3. Protective function:

• Thick mucus present in gastric juice protects the stomach wall from injury and from the action of pepsin and hydrochloric acid.

4. Hemopoietic function:

• Gastric juice contains intrinsic factor essential for the absorption of Vit B12 from intestine.

5. Excretory function:

• Many substances like toxins, alkaloids, metals are excreted through gastric juice.