Name______Period______

Integumentary System Lab

Part 1: Integumentary System

Microscopic Examination of the Skin

For this portion of the lab, you will examine images from "The JayDoc Histoweb" made available by the University of Kansas Medical Center at the following web address:

http://www.kumc.edu/instruction/medicine/anatomy/histoweb/skin/skin.htm

1.  View Slide 1.

a.  Question: What is the blue arrow pointing at? ______

2.  View Slides 2 and 3.

a.  Question: What is the name of the pigment that makes the stratum basale so dark? ______

3.  View Slide 3.

a.  Question: What is the name of the pink, fibrous-looking tissue on the outer layer? ______

b.  Question: What is the hard, insoluble protein fiber that is included in the outer layer of cutaneous membrane? ______

4.  View Slide 4.

a.  Question: In which layer of the skin are sweat glands found? ______

5.  View Slides 5 and 6.

a.  Question: In which layer of the skin are hair follicles rooted? ______

6.  View Slide 7.

a.  Question: The sebaceous glands are emptying their contents where? ______

7.  View Slide 8.

a.  Question: What is the blue arrow pointing at? ______

b.  Question: What is that structure’s function? ______

8.  View Slide 9.

a.  Question: The thickness of which layer distinguishes thick and thin skin? ______

9.  View Slide 10.

a.  Question: To which strata layer is the yellow arrow pointing? ______

b.  Question: The blue arrow? ______

c.  Question: The red arrow? ______

d.  Question: The black arrow? ______

e.  Question: The green arrow? ______

Integumentary System Questions

1. List three functions of skin.

a. ______

b. ______

c. ______

2. Which portion of the epidermis has actively reproducing cells?______

3.  Blood vessels and nerves are present in which layer of skin? ______

4.  In what layer of skin do you find melanocytes and keratinocytes? ______

5.  What product is produced by the cell types mentioned in question 4? ______& ______

6.  Name two types of cutaneous or skin glands? ______& ______

7.  What are the secretions of the glands mentioned in question 6? ______& ______

8.  Are the two glands found in skin exocrine or endocrine? ______

9.  What do the nails you clip, the hair you cut, and the skin you slough off have in common? ______

Part 2: Skin Sensation

Two-Point Sensibility (need caliper and ruler)

The density of touch receptors varies significantly in different areas of the body. Areas with heightened ability to “feel” tend to be those with fine motor control.

§  Using a caliper and a ruler, test the ability of the subject to differentiate two distinct sensations when the skin is touched simultaneously at two points.

§  Have your partner close their eyes. With the caliper arms completely together, gently place the point on the inner surface of the forearm.

§  Gradually increase the distance between the arms, testing the subject’s skin after each adjustment. Continue testing until the subject reports that two points of contact can be felt.

§  This measurement, the smallest distance at which two points of contact can be felt, is the two-point threshold.

§  Repeat on the back of the neck and the fingertip.

Body area tested / Forearm / Neck / Fingertip
Two-Point Threshold (mm)

§  Which body area tested has the greatest density of touch receptors? ______

§  In which layer of the skin do these pressure receptors reside? ______

Touch Receptor Adaptation (need 3 pennies)

When a stimulus is applied for a prolonged period, the rate of receptor response slows and awareness of the stimulus declines or is lost (adaptation) until a stimulus change occurs (ie: clothes on skin).

·  With the subject’s eyes closed, place a coin on the anterior surface of the forearm. Record the duration of the sensation. ______sec

·  Repeat the test, placing the coin at a different forearm location. How long does the sensation persist at the second location? ______sec

·  After adaptation at the second site, stack two more coins atop the first one. Does the pressure sensation return? ______If so, for how long is the subject aware of the greater pressure? ______sec.

·  Why is this phenomenon helpful to humans, who wear clothes all the time? ______