Table of contents

1. Introduction to Anatomy & Physiology5h 43m
2. Cell Chemistry & Cell Components12h 36m
3. Energy & Cell Processes10h 6m
4. Tissues & Histology10h 3m
5. Integumentary System2h 20m
6. Bones & Skeletal Tissue2h 16m
7. The Skeletal System2h 35m
8. Joints2h 17m
9. Muscle Tissue2h 33m
10. Muscles1h 11m
11. Nervous Tissue and Nervous System1h 35m
12. The Central Nervous System1h 6m
- Introduction to the Central Nervous System
  18m
- The Cerebrum
  48m
13. The Peripheral Nervous System1h 26m
14. The Autonomic Nervous System1h 38m
15. The Special Senses2h 41m
16. The Endocrine System2h 48m
17. The Blood3h 22m
18. The Heart3h 42m
19. The Blood Vessels3h 35m
20. The Lymphatic System3h 16m
21. The Immune System14h 37m
22. The Respiratory System3h 20m
23. The Digestive System2h 5m
24. Metabolism and Nutrition4h 0m
25. The Urinary System2h 39m
26. Fluid and Electrolyte Balance, Acid Base Balance37m
27. The Reproductive System2h 5m
28. Human Development1h 21m
29. Heredity3h 32m

23. The Digestive System

Introduction to the Digestive System

Anatomy & Physiology

23. The Digestive System

Introduction to the Digestive System

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Multiple Choice

What happens to pepsin when it enters the small intestine?

Pepsin is converted into trypsin.

Pepsin continues to digest proteins effectively.

Pepsin is inactivated due to the alkaline environment.

Pepsin aids in the absorption of nutrients.

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Verified step by step guidance

Understand the role of pepsin: Pepsin is an enzyme that digests proteins in the stomach, where the environment is highly acidic (pH around 1.5 to 3.5).

Recognize the change in environment: When pepsin enters the small intestine, it encounters a different environment. The small intestine has an alkaline pH, typically around 7 to 8, due to the presence of bicarbonate ions secreted by the pancreas.

Consider the effect of pH on enzyme activity: Enzymes like pepsin have an optimal pH range in which they function effectively. Pepsin's optimal pH is acidic, so a shift to an alkaline environment affects its activity.

Determine the outcome for pepsin: In the alkaline environment of the small intestine, pepsin becomes inactivated because it is outside its optimal pH range. This means it can no longer effectively digest proteins.

Clarify the misconception: Pepsin is not converted into trypsin. Trypsin is a different enzyme that is activated from trypsinogen in the small intestine and continues the process of protein digestion in this alkaline environment.