Solutions To Exercises Lesson

1. The integumentary system includes the integument proper (skin) and the integumentary derivatives (hairs, nails, and glands of the skin). (para 3-1a)

2. Another name for the integument proper is the skin. (para 3-1a)

3. Three types of integumentary derivatives are the hair, nails, and various glands of the skin. (para 3-1a)

4. A fascia is a sheet or collection of fibrous connective tissue (FCT). (para 3-1b)

5. The subcutaneous layer (superficial fascia) is the connective tissue which lies immediately beneath the skin. (para 3-1b)

6. Deep fasciae are found as envelopes for muscles and other organs and they fill spaces. (para 3-1b)

7. The investing deep fascia is the third envelope of the whole body beneath the skin and the subcutaneous layer. (para 3-1b)

8. The outer layer of the skin is the epidermis. The inner and deeper layer of skin is the dermis. (para 3-3)

9. The epidermis is a stratified squamous epithelium.

The basic structure of the innermost layer of the epidermis is a single layer of columnar-type epithelial cells.

The cells found in the outermost layers of the epidermis are transparent, flattened, dead, cornified, and without nuclei. (para 3-3a)

10. The dermis is dense FCT consisting of white and yellow fibers. Papillae are finger-like projections of the dermis that extend into the epidermis.

Papillae prevent the dermis and epidermis from sliding on each other. Other structures found in the dermis include blood vessels, lymph vessels, nerve endings, hair follicles, and glands. (para 3-3b)

11. A hair follicle is formed by the extension of the skin (dermis and epidermis) deeper into the surface of the body. At the base of the hair follicle is the hair root. The hair shaft grows out from the root. The hair shaft is made of cells from the outermost layers of the epidermis. (paras 3-5a, b)

12. Sweat glands consist of a coiled secretory portion and a wavy duct which leads to the surface of the skin. (para 3-6a)

13. Sebaceous glands produce an oily substance. Its function is to lubricate the skin and hairs and to keep them flexible. The sebaceous glands are usually found as a part of the walls of hair follicles. (para 3-6b)

14. In mammary glands, milk ducts connect each nipple with lobes of glandular tissue. Fat and fibrous CT fill in the spaces among the lobes. (para 3-6c)

15. Nails are found on the ends of the digits. Nails help to protect the ends of these digits. The nail itself is made up of cornified (hardened) outer cell layers of the epidermis. The nails grow continuously from their roots. (para 3-7)

16. The term serous refers to a watery-type fluid. Serous cavities are sacs lined with serous membranes. These cavities serve as lubricating devices. (para 3-12)

17. Each bursa is a small sac located between two moving structures, usually a muscle moving over a bony surface. The bursa reduces the friction between the two structures. The serous membrane lining the cavity within a bursa is a simple squamous epithelium and it secretes a serous fluid into the serous cavity. (para 3-13)

18. Each lung is encased in a serous cavity called the pleural cavity. The heart lies in a serous cavity called the pericardial cavity, the intestines move freely within the peritoneal cavity. (para 3-14a)

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