The Integumentary System
FOCUS: The integumentary system consists of the skin, hair, nails, and a variety of glands. The epidermis of the skin provides protection against abrasion, ultraviolet light, and water loss, and produces vitamin D. The dermis provides structural strength and contains blood vessels involved in temperature regulation. The skin is attached to underlying tissue by the hypodermis, which is a major site of fat storage.
CONTENT LEARNING ACTIVITY
❛❛The hypodermis is not part of the integumentary system.❜❜ Match these terms with the correct statement or definition:
Fat Hypodermis 1. Sometimes called subcutaneous tissue. 2. Loose connective tissue that attaches the skin to underlying bone or muscle. 3. Functions as padding and insulation. 4. Responsible for some of the structural differences between men and women.
The hypodermis contains about half the body's stored fat. Measuring the thickness of the hypodermis is a technique used to estimate total body fat.
❛❛The dermis is dense connective tissue that forms the deep layer of the skin.❜❜ Match these terms with the correct statement or definition:
Cleavage lines Dermal papillae Striae 1. Directions in which the skin is most resistant to stretch. 2. Lines visible through the epidermis produced by overstretching of the dermis. 3. Blood vessels in this structure exchange nutrients and waste products with the epidermis. 4. Projections from the dermis into the epidermis; produce fingerprints.
❛❛The epidermis is stratified squamous epithelium separated from the dermis by a❜❜ basement membrane. A.
Match these terms with the correct statement or definition:
Callus Corn Keratin Keratinization
Lipids Stratum basale Stratum corneum
1. The process that changes the shape and chemical composition of epidermal cells. 2. The strata of the epidermis that produces new cells by mitosis. 3. The strata of the epidermis that contains dead, squamous cells. 4. Responsible for the structural strength of the stratum corneum. 5. Responsible for preventing fluid loss through the skin. 6. A thickened area of stratum corneum produced in response to friction. 7. Stratum corneum that thickens to form a cone-shaped structure over a bony prominence.
The epidermis forms a permeability barrier that is also resistant to abrasion.
Match these terms with the correct part labeled in figure 5.1: Dermis Epidermis Stratum basale Stratum corneum
1. 2. 3. 4.
❛❛Skin color is determined by pigments in the skin, by blood circulation through the skin, and by❜❜ the thickness of the stratum corneum.
Using the terms provided, complete these statements:
Albinism Birthmarks Blue color Carotene Cyanosis Melanin Melanocytes Melanosomes Red color Suntan
1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
(1) is the term used to describe a group of pigments responsible for skin, hair, and eye color. It is produced by (2) in the stratum basale, packaged into (3) , and is distributed to other epidermal cells. Melanin production is determined by genetic factors, hormones, and exposure to light. A mutation that prevents the manufacture of melanin is called (4) . Increased melanin production in response to ultraviolet light results in a (5) . The (6) of tattoos, bruises, and some superficial blood vessels is due to the lightscattering effect of overlying tissues. (7) is a yellow pigment found in plants such as squash and carrots. When large amounts of this pigment are consumed, the excess accumulates in the stratum corneum and in fat cells of the dermis and hypodermis, causing the skin to develop a yellowish tint. Blood flowing through the skin produces a (8) . When blood flow increases (e.g., blushing) this color intensifies. A decrease in the blood oxygen content of blood produces a bluish color called (9) . Congenital disorders of blood vessels in the dermis produce (10) .