Chapter 6

The Integumentary System

Topic of lesson

The Epidermis

Learning objectives

At the end of the lesson, the student should be able to

• list the five types of cells in the epidermis;
• describe the histological structure of the epidermis;
• explain the life history of a keratinocyte.

Pre-assignment

Watch the video: What is skin? (Epidermis) on Khan Academy

Activity

1. Students use microscopes to observe human skin slides. They can find that the skin is layered. The dividing line at the bottom is uneven and will explain later this is the dividing line between the epidermis and the dermis.
2. Teacher uses PPT to introduce the names and functions of five kinds of cells in the epidermis. Each cell is represented by a different color card. (For example yellow cards for Stem cells and brown cards for Melanocytes)
3. Students make a table in their notebooks listing the names and roles of each cell.
4. Teacher uses a diagram to explain the histological structure of the epidermis; introduce the name and characteristics of the five layers.
5. Students rub their arms and hair on a black paper and observe with a magnifying glass to see if dead skin fell.
6. Teacher introduce the life history of a keratinocyte including how it develops from the bottom up and eventually dies.
7. Students use the microscopes to observe the slides again, color and label the worksheet of epidermis layers.
8. A group of four students get a set of cell cards, including a red special cell. They need to show the position change of this red cell in the epidermis by time-lapse photography.
9. *Teams complete the time-lapse photography quickly can do research for a future case study on the importance of the epidermis such as its role in immune responses, wound healing or vitamin D production.

Resources

• Science notebook, black paper, different color cards, Epidermis layers worksheet
• Microscopes, human skin slides, magnifying glasses, iPads