neither life nor health depends. QUESTIONS 1. What organs constitute the digestive apparatus? 2. Describe mastication; insalivation. 3. Name the glands which secrete saliva. 4. Is the reaction of saliva acid or alkaline? 5. Describe the physiologic (physical) action of saliva; chemical. 6. What change takes place in the bloodvessels of the mucous membrane of the stomach during digestion? 7. What part do the muscular coats of the stomach play during digestion? 8. How is the food held within the stomach while the walls contract upon it? 9. What do you understand by the term chyme? 10. How long does digestion last in the stomach? 11. What juice is secreted from the glands of the mucous mem- brane of the stomach during digestion? 12. Do the blood or lymph vessels absorb any nourishment from the stomach? 13. Is gastric juice acid or alkaline in reaction during digestion? QUESTIONS 285 14. What is the acidity due to? What percentage of hydrochloric acid is normally present in the gastric juice? 15. What is the function of pepsin in the gastric secretion? Rennin? 16. Is the intestinal secretion acid or alkaline in reaction? 17. Name the enzymes found in the pancreatic juice. 18. Give briefly the function of the enzymes trypsin, amylopsin, steapsin, as regards their action during intestinal digestion. 19. Name the enzyme present in the intestinal juice and give its function. 20. What cells secrete the bile and how does it leave the liver?' 21. Name the organ in which bile is stored. 22. How does the bile reach the intestine from the liver and gall-bladder? 23. Give the physiologic functions of bile. 24. Give the contents of the colon following intestinal digestion. 25. Give the capacity of the infant's stomach at birth; two, four, six, eight, ten, twelve, fourteen to eighteen weeks; five to six, seven to eight, twelve to fourteen months. 26. Describe the functions of the stomach during gastric digestion in infants. 27. In which portion of the alimentary canal is the nourishment absorbed from during infant digestion?
Key Takeaways
- The stomach's muscular coats play a crucial role in holding and processing food.
- Gastric juice is primarily acidic, containing about 0.5% hydrochloric acid.
- Bile aids in the digestion of fats by emulsifying them.
Practical Tips
- Monitor infants' feeding patterns closely to ensure proper nutrition during critical times.
- Understand that gastric juices are highly acidic and can cause burns if ingested in large quantities.
- Recognize the importance of bile for fat digestion, which is crucial even in emergency situations.
Warnings & Risks
- Be cautious with infants' stomach capacities; overfeeding can lead to discomfort or complications.
- Avoid administering strong acids or digestive juices directly as they can cause severe damage.
- Understand that improper digestion can lead to malnutrition and other health issues, especially in emergencies.
Modern Application
While the historical techniques described in this chapter provide foundational knowledge on digestion, modern medical practices have refined our understanding of nutrition and emergency response. Key principles such as monitoring stomach capacity and recognizing the importance of bile for fat digestion remain crucial, even with advanced technology.
Frequently Asked Questions
Q: What is chyme, and how long does it stay in the stomach?
Chyme refers to the semi-liquid mass of partially digested food that remains after passage through the stomach. Digestion typically lasts about four hours in adults.
Q: How do blood or lymph vessels contribute to digestion?
Blood and lymph vessels do not directly absorb nourishment from the stomach but play a role in transporting nutrients throughout the body once absorbed by the intestines.
Q: What enzymes are found in pancreatic juice, and what do they do?
Pancreatic juice contains trypsin, amylase (amylopsin), and lipase (steapsin). Trypsin breaks down proteins, amylase breaks down carbohydrates, and lipase breaks down fats.