Integumentary Systemlab Manual Exercises: Exercise 7

Integumentary SystemLab Manual Exercises: Exercise 7

Learning Outcomes:

1) Identify the major and minor layers of skin from slides and models.

2) Know which tissues are found in each of the above layers.

3) Compare and contrast the presence of nervous tissue and blood vessels in each layer.

4) Describe the origin and function of skin derivatives (sebaceous glands, etc)

5) Compare distribution of skin glands on different parts of the body.

6) Classify fingerprint patterns and discuss functions of fingerprints.

7) Measure body fat using various methods.

Activity 1: Locating structures on a skin model

1) Obtain a 3D skin model from your instructor

2) Photograph or make a drawing of the model in your lab notebook

3) Label the following structures AND list tissues present and their functions

Epidermis

Dermis

Hypodermis

Hair Follicle

Sebaceous Gland

Eccrine Sweat Gland

Arrector Pili Muscle

Dermal Papillae

Pacinian Corpuscle

Blood Vessels

Free Nerve Ending

Root hair plexus

Activity 2: Comparison of hairy & hairless skin

1) Obtain a prepared slide of hairy (scalp) and hairless (sole of foot) skin.

2) Make a drawing of each at an appropriate magnification. You should be able to see all layers of the epidermis and dermis.

3) Label the following layers:

Stratum Corneum

Stratum Lucidum

Stratum Granulosum

Stratum Spinosum

Stratum Basale

Dermal Papilla

Dermis- Reticular layer

Hypodermis

4) Question: In which way (besides the presence or absence of hair) does “hairy” skin differ from “hairless” skin?

Activity 3: Plotting the distribution of sweat glands.

In this activity, we will compare the density of sweat glands on thick (palms) and thin skin (forearm) by doing a short in-class experiment.

1) Form a hypothesis as to which area will have more sweat glands.

2) Select a minimum of 10 subjects for the experiment. MAKE SURE THEY ARE NOT ALLERGIC TO IODINE!

3) Paint both skin regions with iodine and dab dry repeatedly with fresh paper towels until no iodine appears on the towel.

4) Securely tape 0.5 cm2 of parchment paper over each skin area.

5) Have the participant engage in strenuous exercise (e.g. treadmill or bicycle) for 2-5 minutes.

6) Afterwards, have the student sit quietly for an additional 5 minutes.

7) Remove the papers and tape, blue-side up, to a 3x5 note card. Label with student name and region of skin.

8) Count the number of blue dots per each square. Multiply each by 2 to obtain # of sweat glands per cm2. (Discard any samples which are over-stained or un-readable)

9) Return the 3x5 card to the donor student so that it may be included in their lab notebook.

10) Discuss results in class stating whether or not your hypothesis was supported. Discus any other factors which may have affected your results.

Activity 4: Identifying Fingerprints

1) Use the ink pad and index card to get you fingerprints (one hand only)
2) Each student should classify the pattern of each fingerprint pattern. Write the pattern type next to each fingerprint and include in your lab notebook.

3) You can use the fingerprint kit to take finger prints off of the lab bench or metal faucet.

4) With a clean surface and fingers leave a fingerprint mark.

5) Dust the slides for fingerprints.