<p> THE INTEGUMENTARY SYSTEM The skin is made of two distinct layers: the epidermis and the dermis. These layers are firmly attached to one another. Under the dermis is a subcutaneous layer called the hypodermis. You and your lab partner are about to construct a model of the skin. You need to follow directions carefully. Use your book (pages 134-144; and 345 Figure 11.10 a) as a reference. Epidermis: The epidermis is keratinized, stratified, squamous epithelium consisting of four to five layers. The deepest layer, the stratum basale, is a single layer of mitotically active cells. The layer directly superior to the stratum basale is the stratum spinosum. The stratum spinosum consists of several layers of flattened, irregularly shaped cells. This layer is also mitotically active. The next layer is the stratum granulosum. The stratum granulosum is thin region of only two to three layers of flattened cells. In thick skin, as found on the soles of your feet, two or three cell layers of clear flattened cells are found above the stratum granulosum. The outer most layer of cells is called the stratum corneum and consists of twenty to thirty layers of dead cell remnants. Directions: 1. On pages 47 and 48 of the handouts, cut along the thick, dark wavy line. 2. On page 47, the stratum corneum is represented by dashed lines. Using a black marker or colored pencil, extend these dashes until they stretch all the way across the epidermis of both page 47 and 48. </p><p>3. Add each of the following epidermal layers and color each as indicated below. Be sure to make the thickness of each layer proportional to what it is in real life.</p><p> stratum basale (plum) stratum spinosum (orange) stratum granulosum (light pink) stratum corneum (white w/ black dashes)</p><p>4. The black stars represent melanocytes which produce pigment. Add more across the stratum spinosum and granulosum of both pages. 5. Cut out & color each of the following nerve endings as directed below. Refer to pg 345 fig.11.10 (a). free dendrite nerve endings (grey) Merkel discs (blue-grey)</p><p>6. Glue the top of the free dendrite nerve endings and Merkel discs to their appropriate location on page 47. When finished you should be able to lift each and read what is written under it.</p><p>7. Tape page 47 to page 48 as directed on the paper.</p><p>8. Using black marker, label all structures with their scientific names. (i.e. instead of "light touch" write Merkel discs)</p><p>9. Write the function of the epidermis in the space above the stratum corneum. </p><p>Dermis: The dermis is made of strong but flexible connective tissue with reticular, collagen, and elastic fibers. Many nerve endings found in this layer have special names. Refer to Figure 11.10 on page 345 of your text to determine the true name of each. Directions: 1. Cut along the right hand wavy dark line of pages 45 and 46. 2. Each of the following structures is found within the epidermis. Locate on pages of 45 and 46 of the hand out and color as directed below. Nerves (grey) Meissner's Corpuscles (maroon) Pacinian's Corpusles (pink) Sebaceous glands (turquoise) Arrector pili muscles (violet) Sudoriferous glands (teal) Krause's end bulbs (sky blue) Ruffini's Corpuscles (orange) 1 Arteries - left (dark red) Veins -right (navy) Capillaries (left ½ red right½ blue) Connective tissue (lavender) Hair (dark brown) 3. Tape page 45 to page 46 as indicated on the sheets. 4. Write the function of the dermis in the space above the coloring. 5. Tape the epidermis above the dermis as indicated on the sheets. 6. Cut out and glue all other dermal structures to the dermis. When gluing nerve endings only glue the top edge so they can be raised to read what is below them. When attaching the hair, glue it only to the dermis. DO NOT glue it to the epidermis!</p><p>7. Label all structures with their scientific names & with black marker. (i.e. instead of oil gland write sebaceous gland)</p><p>Hypodermis: The hypodermis is made of loose connective tissue that varies from adipose to areolar in nature. Directions: 1. Each of the following structures is found within the epidermis. Locate on pages of 43 and 44 of the hand out and color as directed below. Adipose tissue (yellow) Areolar tissue (rose) Sudoriferous gland (teal) Nerves grey Arteries - superior (dark red) Veins - inferior (navy) Capillaries (left ½ red right½ blue) 3. Label all structures with black marker. 4. Tape page 42 to page 44 as indicated on the sheets. 5. Write the function of the hypodermis in the space above the coloring. 6. Tape the dermis above the hypodermis as indicated on the sheets. Final Touch Directions: 1. Color the oil drops coming out of the hair follicle light pink. 2. Add three drops of sweat coming out of the sudoriferous gland and color them blue.</p><p>2 Students Names: ______Period____ Due Date: ______</p><p>GRADING MATRIX: SKIN MODEL Points Score Possible Epidermis 1. Extended stratum corneum using marker/colored pencil 2 2. Stratum basale (dark purple) 2 3. Stratum spinosum (orange) 2 4. Stratum ganulosum (pink) 2 5. Melanocytes added - black stars 2 6. Free dendrite nerve endings (gray) 2 7. Merkel discs (red) 2 8. All structures labeled in black marker 6 9. Function of epidermis indicated 6 10 Cut and taped correctly 6 . 11 Total 32 . Dermis 1. Nerves (gray) 2 2. Meissner’s Corpuscles (light brown) 2 3. Pacinian Corpuscles (light pink) 2 4. Sebaceous glands (dark pink) 2 5. Arrector pili muscles (red) 2 6. Sudoriferous glands (dark green) 2 7. Krause’s end bulbs (light blue) 2 8. Ruffini’s Corpuscles (orange) 2 9. Arteries (red) 2 10. Veins (blue) 2 11. Capillaries (½ red ½ blue) 2 12. Connective tissue (light purple) 2 13. Hair (dark brown) 2 14. All structures labeled in black marker 6 15. Function of epidermis indicated 6 16. Cut and taped correctly 6 17. Total 44 Hypodermis 1. Adipose tissue (yellow) 2 2. Arteries (red) 2 3. Veins (blue) 2 4. Capillaries (½ red ½ blue) 2 5. Nerves (gray) 2 6. Sudoriferous glands (dark green) 2 7. All structures labeled in black marker 6 8. Function of epidermis indicated 6 9. Total 24 Other Neatness 6 Wow Factor</p><p>3</p>