Unit One Integumentary System
The finest clothing made is a person's own skin, but, of course, society demands something more than this.
?D?DMark Twain (1835?D1910, American writer)
Introductory Remarks
The integumentary system is made up of skin, hair, nails, and exocrine glands. The major function of the system is the protection that the skin gives to underlying tissues. Skin, only a few millimeters thick, is the largest organ in the body. It keeps most harmful substances out, as well as prevents the loss of body fluids. Extending from the skin, hair and nails reinforce the skin and protect it from environmental damage. The exocrine glands of the integumentary system produce sweat, oil, and wax to cool, protect, and moisturize the skin's surface.
Part I Introduction to the Integumentary System
Think and Talk
Directions: Skin is the largest organ in our body. Do you know its major functions? How does it protect us against threats from the outside world? Discuss the questions with your partner with the help
of the following words.
epidermis dermis waterproof microbe T-cell
bacteria fungi gland sebum sensation
Watch and Do
Task One: Blank Filling
Directions: Watch the video and fill in the blanks according to what you've heard.
Between you and the rest of the world lies an (1) that makes up 16% of your physical weight. This is your skin, the largest organ in your body: laid out flat, it would cover close to 1.7 square meters of ground. Its purpose may seem obvious?Dto keep our (2) in. But a look beyond the surface (3) that it plays a surprising number of roles in our lives. First, the basics. Skin is the foundation of the integumentary system, which also (4) your hair, nails, and specialized (5) and nerves. Made up of three layers, the epidermis, dermis, and hypodermis, skin’s (6) varies from 0.5 millimeters at its hinnest and up to four millimet