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: Cells

Anatomy & Physiology

5. Integumentary System

The Epidermis: Cells

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2:01 minutes

Problem 3

Textbook Question

The epidermis provides a physical barrier due largely to the presence of
a. Melanin
b. Carotene
c. Collagen
d. Keratin

Verified step by step guidance

Understand the structure and function of the epidermis: The epidermis is the outermost layer of the skin, primarily responsible for providing a physical barrier to protect the body from environmental damage, pathogens, and water loss.

Review the role of keratin: Keratin is a tough, fibrous protein produced by keratinocytes in the epidermis. It contributes to the strength and durability of the skin, making it resistant to physical and chemical damage.

Clarify why melanin, carotene, and collagen are not the primary contributors to the physical barrier: Melanin is a pigment responsible for skin color and protection against UV radiation, carotene is a pigment that contributes to skin coloration, and collagen is a structural protein found in the dermis (not the epidermis) that provides elasticity and strength to deeper layers of the skin.

Focus on keratin's role in the epidermis: Keratin forms a dense network within the cells of the stratum corneum (the outermost layer of the epidermis), creating a tough, protective layer that resists abrasion and water penetration.

Conclude that keratin is the key component responsible for the physical barrier function of the epidermis, as it directly contributes to the skin's protective properties.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Epidermis

The epidermis is the outermost layer of the skin, serving as the first line of defense against environmental threats. It is primarily composed of keratinocytes, which produce keratin, a protein that contributes to the skin's protective barrier. The epidermis also contains melanocytes, which produce melanin, and other cells that play roles in sensation and immune response.

Keratin

Keratin is a fibrous protein that is a key structural component of the epidermis. It provides strength and resilience to the skin, making it resistant to physical damage and water loss. The presence of keratin in the outer layers of the epidermis is crucial for maintaining the integrity of the skin barrier against pathogens and environmental factors.

Skin Barrier Function

The skin barrier function refers to the protective role of the skin in preventing the entry of harmful substances and pathogens while retaining moisture. This function is primarily attributed to the stratum corneum, the outermost layer of the epidermis, which is rich in keratin. A healthy skin barrier is essential for overall skin health and prevents conditions such as dryness and infections.