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

Which of the following statements about the acidic nature of gastric juice is true?

The acidic environment of the stomach is maintained by the secretion of mucus.

Gastric juice has a high pH due to the presence of bicarbonate.

Gastric juice is neutralized by pepsin.

The acidity of gastric juice is primarily due to hydrochloric acid.

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Verified step by step guidance

Understand the composition of gastric juice: Gastric juice is a mixture of hydrochloric acid (HCl), pepsinogen, mucus, and intrinsic factor. The primary component responsible for its acidity is hydrochloric acid.

Recognize the role of hydrochloric acid: Hydrochloric acid is secreted by the parietal cells in the stomach lining. It creates a highly acidic environment with a pH ranging from 1.5 to 3.5, which is crucial for digestion and killing bacteria.

Clarify the function of mucus: Mucus is secreted by the stomach lining to protect it from the corrosive effects of hydrochloric acid. It does not contribute to the acidity but rather serves as a protective barrier.

Understand the role of bicarbonate: Bicarbonate is not a component of gastric juice that contributes to acidity. Instead, it is secreted by the pancreas into the duodenum to neutralize the acidic chyme coming from the stomach.

Identify the role of pepsin: Pepsin is an enzyme activated by the acidic environment of the stomach. It does not neutralize gastric juice but rather functions optimally in acidic conditions to break down proteins.