Lab 4 Integumentary System and Covering and Lining Membranes

Text Chapters 4 and 5(Figures from Ch. 23 and 24)

Using the lab exam review sheet at the end of this exercise and the figures in your textbook:

Locate Structures on the Skin Model

Compare Hairy and Relatively Hair-free Skin Microscopically

Note: human scalp is hairy skin, primate palm or sole is relatively hair-free skin

Locate Sebaceous and Sweat Glands Microscopically

Examine the Microscopic Structure of Mucous Membranes

Obtain slides of the trachea and esophagus and the small intestine (ileum)

Examine the Microscopic Structure of Serous Membranes

Obtain a slide of the small intestine labeled serosa. Look at the outer edge of the intestine to locate the thin layer of epithelial cells and underlying connective tissue (called the visceral peritoneum).


Name______Lab Section ______

1.Plotting the Distribution of Sweat Glands – Turn Parts 1 and 2 in the next time you come to class.

In this experiment we will do a very simple test to estimate sweat gland distribution in two places on the body, the palm and the forearm.

Observations

Working with members of your lab group, discuss patterns of perspiration you have observed on your own bodies at other times. Remember, we are comparing the palm and the forearm. Record your observations below.

Do this first and show it to me before you begin the rest of the lab.

Personal Observations (Before the Experiment):5 points

Hypothesis5 points

The hypothesis should follow from personal observations. Based on your observations, formulate a hypothesis or best guess about the distribution of sweat glands on the forearm and palm. Write your hypothesis as a testable statement. One example of a hypothesis is "There is no difference in sweat gland distribution on the palm and forearm."

Materials

2 white paper squares per person

scotch tape

scissors

Q-tip

iodine

Methods

  • Select a spot on the palm and a spot on the ventral forearm.
  • Using the Q-tip apply iodine to a square centimeter in each area.
  • Let the iodine dry. Put the Q-tip in the trash.
  • Tape a piece of paper over each area and wait 15 to 20 minutes.
  • Remove the paper and look for black spots on the paper. Each black spot represents a sweat gland.
  • Compare the two papers and put your results on the table on the board.
  • Use class results for the results section of the experiment.

Results

Note: For this section use the combined class results, not your personal results. To determine results, count the number of pairs of squares with more dark spots on the palm than the forearm, the number of pairs with more dark spots on the palm than the forearm, and the number of pairs with no difference between the palms and the forearms. 3 points

More on palms than forearms ______No difference ______

More on forearms than palms ______

Prepare a bar graph on the provided graph paper below to report the results. Use a ruler! 2 points

A graph is referred to as a Figure in scientific papers. The label is placed under the graph. Label your graph “Distribution of Sweat Glands on the Palms and Forearms” 1 point

The Y-axis should be labeled Number in Group

One bar on the X-axis should be labeled More on Palm than Forearm

One bar on the X-axis should be labeled More on Forearm than Palm

One bar on the X-axis should be labeled No Difference between Palm and Forearm (total of 4 points)

Under the graph or chart write a one-sentence statement about the results. This should describe the actual results in words and should not be a conclusion. You should include the actual number of responses in each category. Imagine describing the numbers to someone who cannot see the graph.5 points

Figure 1. ______

One sentencestatement describing the Results (see directions above).

Discussion (15 points )

Your discussion should include the following information:

  • Do the data support or not support your hypothesis? Do not use the words prove, disprove or “I feel”. Use support, do not support, “I think”.(5)
  • Were there any factors that might have interfered with data collection? (5)
  • Describe another experiment you might carry out to gain additional information about sweat gland distribution. (5)

2. Comparison of Covering and Lining Membranes

a. Compare and contrast mucous and serous membranes. Give one structural similarity and one structural difference.

  1. Similarity. Both have ______

______

  1. Difference______

______

b. Draw two examples of mucous membranes and one of a serous membrane from the slides in lab. Label epithelium type and indicate the underlying connective tissue. Use a ruler and print labels in the margins. Indicate what you are looking at (esophagus, trachea, small intestine/ileum or serous membrane slide)and total magnification beneath the figures. Information is in Ch. 4-6.

Slide ______Slide ______

Membrane Type______Membrane Type______

______X______X

Slide______

Membrane Type ______

Total Magnification ____X

Do at home and show to me. This figure is on the first exam. I will not grade this but

will check the labels and return this to you for corrections (if necessary).

Label the skeleton. Print the labels in the margins, not on the lines . This figure will be on test 1. Use Exercises 10 and 11 in the lab manual or figures in the text if you need help.

For Lab Exam

Integumentary System

Be able to identify figures or the model (if applicable):

  • stratum corneum
  • stratum lucidum
  • stratum granulosum
  • stratum spinosum
  • stratum basale
  • dermal papillae
  • papillary layer
  • reticular layer
  • hypodermis
  • sebaceous gland
  • eccrine sweat gland
  • apocrine sweat gland
  • hair shaft
  • hair follicle
  • hair root
  • epidermis
  • dermis

Be able to identify on prepared slides:

  • stratum corneum
  • stratum lucidum
  • stratum granulosum
  • stratum spinosum
  • stratum basale
  • dermal papillae
  • hypodermis
  • sebaceous gland
  • sweat gland
  • hair follicle
  • hair root
  • epidermis in general
  • dermis in general

Know tissue types of epidermis and dermis. Be able to distinguish between skin of palm and skin of scalp.

Be able to interpret data from the sweat gland experiment.

Covering Membranes

Figures in text, histology atlas and handout. Some figures in chapters 23 and 24.

Recognize and distinguish among cutaneous, serous and mucous membranes.