Essentials of Anatomy and Physiology

6. Apocrine sweat glands—modified scent glands in
   axillae and genital area; activated by stress and
   emotions.


7. Eccrine sweat glands—most numerous on face,
   palms, soles. Activated by high external tempera-
   ture or exercise; sweat on skin surface is evaporated
   by excess body heat; potential disadvantage is dehy-
   dration. Excretion of small amounts of NaCl and
   urea is a very minor function.


8. Arterioles—smooth muscle permits constriction
   or dilation. Vasoconstriction in cold temperatures
   decreases dermal blood flow to conserve heat in
   the body core. Vasodilation in warm temperatures
   increases dermal blood flow to bring heat to the
   surface to be lost. Vasoconstriction during stress
   shunts blood away from the skin to more vital

organs, such as muscles, to permit a physical

response, if necessary.

Subcutaneous Tissue—also called the superfi-

cial fascia; connects skin to muscles (see Fig.

5–1 and Table 5–3)

1. Areolar tissue—also called loose connective tissue;
   the matrix contains tissue fluid and WBCs that
   destroy pathogens that get through breaks in the
   skin; mast cells produce chemicals that bring about
   inflammation.


2. Adipose tissue—stores fat as potential energy;
   cushions bony prominences; provides some insula-
   tion from cold. Other functions: contributes to
   appetite, the use of insulin, and the activation of
   WBCs.

102 The Integumentary System

REVIEW QUESTIONS

1. Name the parts of the integumentary system.
   (p. 90)


2. Name the two major layers of skin, the location
   of each, and the tissue of which each is made.
   (pp. 90, 95)


3. In the epidermis: (pp. 90, 93)
   a. Where does mitosis take place?
   b. What protein do the new cells produce?
   c. What happens to these cells?
   d. What is the function of Langerhans cells?


4. Describe the functions of the stratum corneum.
   (p. 90)


5. Name the cells that produce melanin. What is
   the stimulus? Describe the function of melanin
   (p. 94)


6. Where, on the body, does human hair have impor-
   tant functions? Describe these functions. (p. 95)
   7. Describe the functions of nails. (p. 96)
   8. Name the cutaneous senses. Describe the impor-
   tance of these senses. (p. 96)
   9. Explain the functions of sebum and cerumen.
   (pp. 96–97)


7. Explain how sweating helps maintain normal
   body temperature. (p. 98)


8. Explain how the arterioles in the dermis respond
   to cold or warm external temperatures and to
   stress situations. (p. 98)


9. What vitamin is produced in the skin? What is the
   stimulus for the production of this vitamin?
   (p. 90)


10. Name the tissues of which the superficial fascia is
    made. Describe the functions of these tissues.
    (p. 99)