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

Previous problemNext problem

Problem L3.B5d

Textbook Question

Many antiaging skin creams contain collagen and hyaluronic acid. Manufacturers claim that the collagen and hyaluronic acid applied to the surface of the skin will be absorbed into the dermis, where they will be incorporated into dermal tissue.
Predict the effectiveness of the creams.

Verified step by step guidance

Understand the structure of the skin: The skin consists of three main layers—epidermis, dermis, and hypodermis. The epidermis, the outermost layer, acts as a barrier to protect underlying tissues and is composed of tightly packed cells, including keratinocytes, which limit the penetration of large molecules.

Analyze the molecular size of collagen and hyaluronic acid: Collagen is a large protein, and hyaluronic acid is a large polysaccharide. Both have high molecular weights, making it difficult for them to penetrate the epidermis and reach the dermis.

Consider the role of the stratum corneum: The stratum corneum is the outermost layer of the epidermis and is composed of dead keratinized cells. It is highly effective at preventing the entry of large molecules, including collagen and hyaluronic acid, into deeper layers of the skin.

Evaluate the claims of manufacturers: While collagen and hyaluronic acid are essential components of the dermis, their topical application is unlikely to result in absorption into the dermis due to the skin's barrier properties. Instead, these creams may provide temporary hydration or a plumping effect on the surface of the skin.

Conclude the effectiveness: Based on the anatomy and physiology of the skin, the claims that collagen and hyaluronic acid in antiaging creams are absorbed into the dermis and incorporated into dermal tissue are not supported. Their primary benefit is likely limited to surface-level effects, such as moisturizing the skin.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above

Play a video:

Was this helpful?

Key Concepts

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

Collagen

Collagen is a structural protein that provides strength and elasticity to the skin. It is naturally produced by the body and plays a crucial role in maintaining skin firmness and hydration. However, when applied topically, collagen molecules are often too large to penetrate the skin barrier effectively, raising questions about the efficacy of collagen in anti-aging creams.

Hyaluronic Acid

Hyaluronic acid is a naturally occurring substance in the body that helps retain moisture in the skin, making it appear plump and hydrated. It can hold up to 1,000 times its weight in water, which is beneficial for skin hydration. While topical application can improve skin moisture levels, its ability to penetrate deeply into the dermis is limited, affecting its overall effectiveness in anti-aging products.

Skin Absorption

Skin absorption refers to the process by which substances penetrate the skin barrier and enter the underlying layers. The stratum corneum, the outermost layer of skin, acts as a barrier to many large molecules, including proteins like collagen. Understanding the mechanisms of skin absorption is essential to evaluate the potential effectiveness of topical treatments, as many active ingredients may not reach the dermis where they are claimed to exert their effects.

Watch next

Master Introduction to Layers of the Epidermis with a bite sized video explanation from Bruce Bryan

Start learning

Related Videos

Related Practice

Textbook Question

The type of skin tumor that involves the keratinocytes of the stratum spinosum is:

a. Basal cell carcinoma

b. Squamous cell carcinoma

c. Malignant keratocytoma

d. Malignant melanoma

After Ramon's skin came into contact with a poison ivy plant in biology lab, he developed a painful, itchy rash. However, after the skin of his colleague Cathy came into contact with snake venom in the lab, she developed no skin irritation. Poison ivy plants contain lipid-soluble oils, whereas snake venoms contain mostly water-soluble peptides. Explain why Ramon developed a rash, whereas Cathy did not.

415

views

Textbook Question

Many antiaging skin creams contain collagen and hyaluronic acid. Manufacturers claim that the collagen and hyaluronic acid applied to the surface of the skin will be absorbed into the dermis, where they will be incorporated into dermal tissue.

Are these substances polar or nonpolar?

376

views

Textbook Question

Predict whether or not these substances are likely to be absorbed by the epidermis.

395

views

Multiple Choice

What is the deepest layer of the epidermis?

110

views

Multiple Choice