Unit 2

Integumentary System

Understandings

• The structures and functions within the Integumentary System.

• Understanding diseases and injuries related to the Integumentary System

Essential Questions

• What are the structures and the functions of the skin and the body’s membranes?

• How does the body’s skin and the membranes protect and lubricate?

Key Concepts / Skills

1. The interrelatedness of various microscopic structures within the Integumentary System.

2. The results of injuries and diseases on the Integumentary System.

Assessments

• Performance based Assessment (PBA) – Preparation and presentation of a skin model

• Lab report, worksheet, discussion, test

Standards

LS1 List, give its location and compare the structure (tissue makeup) of each of the four membrane type.

LS1 When provided with a model or diagram of the skin, recognize, name and describe the distribution and function for

structures of the skin.

LS1 Name the factors that determine skin color, and describe the function of melanin.

LS1 Differentiate between various degrees of burns.

LS4 Summarize the characteristics of skin cancer.

Common Misconceptions

1. The only function skin has is keeping bacteria out.

2. It is often difficult at first for students to “see” all of the different structures found in skin when looking at actual cross sections, as compared to structures represented in diagrams. The more samples they see, the better their understanding of what they are seeing. Microscopic slides of various healthy and diseased skin tissues are not always as nice as the

presentations in textbooks.

3. Skin is an excellent thermoregulator that is frequently taken for granted until discussed in detail.

4. Students are often surprised by the fact that there are similar numbers of melanocytes among people of different ethnic groups, and that it is simply production of melanin that accounts for skin color differences.

5. It is important for students to understand that melanin plays an important role in body protection. It often helps to point out that people with albinism, who are genetically unable to produce melanin, have to be extremely cautious about exposure to

the sun.

6. Students usually don’t realize there are two distinct types of sweat glands producing two distinct products that have separate functions.

7. Hair that has an oval shaft is smooth and silky whereas hair that is flat and ribbonlike is curly or kinky. Students enjoy learning about what makes their hair have the characteristics it has, and appreciate the mechanisms involved in trying to

change their hair type by “perming” and other methods.

8. It is important for students to understand that there are distinct coverings to the organs, and that this pattern of having a visceral as well as parietal covering will be found numerous times as we study various organs.

9. Although vitamin D is produced in the skin and is converted from its inactive to active form by sunlight, it is activated by the kidneys. Functioning kidneys are key to vitamin D availability in the body, thus premature infants with unstable kidneys are at risk for developing rickets and other related diseases.

10. When discussing the consequences of serious burns, refer to the functions of the integument. Loss of skin leads to loss of protection against infection, loss of water, etc.

11. Sunburn that involves blistering is a second-degree burn that requires treatment to prevent infection. Concerning skin cancer, students appreciate knowing what to look for and value the ABCD rule as a good tool for recognizing melanoma.

12. There are over a thousand different disorders related to homeostatic imbalances of the skin. It is helpful to discuss some of the more common skin disorders, such as acne, athlete’s foot, cold sores, and psoriasis, as well as some of the exanthematous skin eruptions, including chicken pox and measles.

13. Discuss the physiology behind alopecia (baldness).

Suggested Learning Activities

1. Developing a museum quality model intend to teach the structure and function of skin.

2. Microscopic examination of skin sections.

Books and Materials

1. Essentials of Human Anatomy & Physiology, Pearson

2. Anatomy & Physiology Coloring Book, Pearson