Anatomy &Physiology -Skin Lab
Name __________________ Date _____
Problem: To investigate the characteristics of skin and view skin cells under the microscope.
Materials: cotton balls, water, alcohol, cornstarch papers, q-tips, iodine solution, clear tape,
toothpicks, clear packing tape, methylene blue, dissecting needle.
Procedure:
Note: Record observations for each part of the procedure on your data table below.
Part 1- Evaporation: quick cool. The rate of evaporation has a direct effect on your
temperature. This is something your skin is very sensitive to. Test each other’s skin with two
liquids that have different rates of evaporation.
1. Dip one cotton ball in alcohol and one in water.
2. Close your eyes. Let your lab partner dab one wrist with alcohol, the other with water.
3. Which one feels cooler? Why? Which liquid evaporates from your skin faster?
Part 2- Sweaty palms: About 2 million of the pores in your skin are connected to sweat-making
glands. Sweat glands are more concentrated in certain skin areas. Here is a test to help you
locate some of yours.
1. Obtain 2 papers that have dried cornstarch solution on them.
2. Using a Q-tip, paint your palm with iodine about 1 inch square.
3. Rub your palms together or clench a fist to work up a sweat.
4. Press the cornstarch paper to your painted palms. Sweat glands will show up as dark
spots. This is evidence of perspiration. What did you observe? Tape the evidence to
your lab paper next to your observations.
Part 3-Skin Prints: If you think your skin is simple, look again. Your skin does a number of
jobs and has a number of appearances. It is thick and thin, light and dark, smooth and wrinkled.
Skin prints are a way to take a closer look at your cutaneous membrane.
1. Rub some soft pencil lead onto a sheet of scratch paper until you get a black blob.
2. Pick up a good smudge on your finger.
3. Carefully pick up the smudge with a piece of clear tape. Pull it away and tape it on to
your lab paper.
4. See how many kinds of skin prints you can find on you body and label at least 3 prints.
Part 4-Touch Points: Your skin is not uniformly sensitive. Some areas have many nerve
endings while other places have few. You might have a few ideas about the sensitive spots.
Here is how to test your hypothesis.
1. Use the toothpicks provided to test point discrimination.
2. Put the toothpicks 2 inches apart on an area of your partner’s skin and press gently.
3. Reduce the distance between pins until he/she feels only one point. Record this distance
on your data table.
4. Repeat this procedure on your partner’s arm, knee, leg, and palm and back of the hand.
5. Record the distance where one poke is felt.
6. What areas were the most sensitive? Why do you think this is so?
Anatomy &Physiology -Skin Lab
Name __________________ Date _____
Part 5- Looking at skin cells:
1. Wash and dry the underside of a wrist that will be sampled for epidermal cells with soap and
water.
2. Stick a clean piece of clear tape on the underside of the washed wrist.
3. Gently remove the piece of tape from the wrist being careful to avoid getting fingerprints on
the tape. A forceps might help to remove the tape and avoid fingerprinting the tape.
4. Place the tape, sticky-side up, on a clean microscope slide.
5. Stain the top, sticky side of the tape with 2 or 3 drops of 1% methylene blue solution.
6. Use a dissecting needle to gently place a cover slip over the sticky tape. Lower the cover slip
down onto the tape and then remove the dissecting needle. This should help prevent staining
your fingers. Caution: Use methylene blue carefully. It will stain most items including skin,
clothing, and table tops.
7. Examine the slide under a microscope. Look for cells with low power first, and then switch to
high power for details.
8. Record your observations of epidermal cells by making drawings. Label your drawings with
appropriate magnifications.
Data Table: Attach drawings /prints to you paper near the observations/results from the lab.
Part
Observations/results
1
2
3
4
5
Conclusion:
--Answer the problem of the lab with specific summary statements that explain your observations.
---List 3 errors you experienced during the lab that may have led to inaccurate results.
1. List the different types of sweat glands.
2. Describe the layers of epidermis in a thick-skinned area.
3. What layer of the skin has cells that reproduce and grow new skin?
4. What is the name of the pigment that gives skin its color? What is the name of the genetic
condition that causes an organism to produce no pigment?
5. Which layer of the skin contains sebaceous glands?