Integumentary System Lab Purpose: Materials: Introduction: Procedure:

Transcription

1 Name: Date: Integumentary System Lab Purpose: To observe the organs and tissues of the integumentary system and to review the functions of these parts. Materials: textbook, hand magnifier or dissecting scope, forceps, microscope slide and cover slip, pipette and water, compound light microscope, prepared microscope slide of scalp, prepared slide of thick skin Introduction: The integumentary system includes the skin, hair, nails, sebaceous glands, and sweat glands. These organs provide a protective covering for deeper tissues, aid in regulating body temperature, retard, water loss, house sensory receptors, synthesize various chemicals, and excrete small quantities of wastes. Procedure: 1. Review the sections entitled Skin and its Tissues and Accessory Organs of the Skin in chapter 6 of your textbook. 2. As a review activity, label figures A, B and C. Figure A 1

2 Figure B 2 Figure C 3. Complete part A of the conclusion questions. 4. Use a hand magnifier or dissecting scope and proceed as follows: a. Observe the skin, hair, and nails of your hand. b. Compare the type and distribution of hairs on the front and back of your forearm.

3 3 5. Use low-power magnification of the compound light microscope and proceed as follows: a. Pull out a single hair with forceps and mount it on a microscope slide. Place a drop of water on top of the hair then cover it with a cover slip being careful not to have any air bubbles around the hair. b. Observe the root and shaft of the hair and note the scale-like parts that makeup the shaft. 6. Complete Part B of the conclusion questions. 7. As vertical sections of skin are observed, remember that the lenses of the microscope invert and reverse images. It is important to orient the position of the epidermis, dermis, and subcutaneous layers using low power before continuing with additional observations. Compare all of your skin observations to the Figures D-H. Use low-power magnification of the compound light microscope and proceed as follows: a. Observe the prepared slide of skin with hair. b. Locate the epidermis, dermis, and subcutaneous layer, a hair follicle, a sebaceous gland, and a sweat gland. You may be able to locate an arrector pili muscle as well. c. Focus on the epidermis with high power and locate the stratum corneum and stratum basale (stratum germinativum). Note how the shapes of the cells in these two layers differ. d. Observe the dense connective tissue (irregular collagenous connective tissue) that makes up the bulk of the dermis. e. Observe the adipose tissue that composes most of the subcutaneous layer. 8. Observe the prepared slide of thick skin. Locate the stratum lucidum. Note how the stratum corneum compares to your observation of the human scalp. 9. Complete part C of the conclusion questions. 10. Using low-power magnification, locate a hair follicle that has been sectioned longitudinally through its bulblike base. Also locate a sebaceous gland close to the follicle and find a sweat gland. Observe the detailed structure of these parts with high power magnification. 11. Complete parts D and E of the conclusion questions.

4 4 Figure D (prickle layer = stratum spinosum) Figure E (hypodermis = subcutaneous) Figure F Figure G

5 Figure H: Sweat Gland and Ducts 5 Conclusion: Part A: Match the structures in Column A with the description and functions in column B. Place the letter of your choice in the space provided. 1. Apocrine sweat gland a. an oily secretion that helps to waterproof body surfaces 2. Arrector pili muscle b. outermost layer of the epidermis 3. Dermis c. Becomes active during puberty 4. Eccrine sweat gland d. Epidermal pigment 5. Epidermis e. Inner layer of skin 6. Hair follicle f. Responds to elevated body temperature 7. Keratin g. pigment-producing cell 8. Melanin h. general name of entire superficial layer of the skin 9. Melanocyte i. gland that secretes an oily substance 10. Sebaceous gland j. Hard protein of nails and hair 11. Sebum k. Binds skin to underlying organs 12. Stratum basale (stratum germinativum) l. Cell division and deepest layer of epidermis 13. Stratum corneum m. Tube-like part that contains the root of the hair 14. Subcutaneous layer n. Causes hair to stand on end and goose bumps to appear

6 Part B Complete the following using complete sentences: 1. How does the skin of your palm differ from that on the back (posterior) of your hand? 6 2. Describe the differences you observed in the type and distribution of hair on the anterior and posterior of your forearm. 3. Explain how hair is formed. Part C 1. Distinguish among the epidermis, dermis, and subcutaneous layer. 2. How do the cells of the stratum corneum and stratum basale (stratum germinativum) differ?

7 3. What special qualities does the connective tissue of the dermis have? 7 Part D 1. What part of the hair extends from the hair papilla to the body surface? 2. In which layer of skin are sebaceous glands found? 3. How are sebaceous glands associated with hair follicles? 4. In which layer of skin are sweat glands usually located? Part E Sketch and label a vertical section of skin using the low power objective. You must label the epidermis, dermis, subcutaneous, dermal papilla, adipose tissue, hair follicle, sebaceous gland, stratum basale, stratum corneum. Be sure to draw it to scale.