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

5. Integumentary System

The Epidermis: Layers

Anatomy & Physiology

5. Integumentary System

The Epidermis: Layers

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Multiple Choice

Which alpha hydroxy acid (AHA) penetrates the epidermis most effectively?

Glycolic acid

Lactic acid

Citric acid

Malic acid

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Verified step by step guidance

Understand the concept of alpha hydroxy acids (AHAs): AHAs are a group of acids commonly used in skincare to exfoliate the skin. They work by loosening the bonds between dead skin cells, promoting cell turnover. Their effectiveness in penetrating the epidermis depends on molecular size and chemical properties.

Analyze molecular size: Smaller molecules penetrate the skin more effectively. Glycolic acid has the smallest molecular size among the listed AHAs, making it more efficient at penetrating the epidermis compared to lactic acid, citric acid, and malic acid.

Consider chemical structure: Glycolic acid has a simple structure with fewer functional groups, which contributes to its ability to penetrate the skin more deeply. Larger or more complex molecules, like citric acid and malic acid, may face more resistance due to their size and structure.

Evaluate pH and solubility: AHAs work best at a lower pH, where they remain in their active form. Glycolic acid is highly effective at lower pH levels, enhancing its ability to penetrate the epidermis compared to other AHAs.

Conclude based on evidence: Based on molecular size, chemical structure, and pH effectiveness, glycolic acid is the AHA that penetrates the epidermis most effectively.