Laboratory 2: Epithelia and Integument
Exercises 6 and 7
The objectives of
Lab 2 are: 1. Learn histology and 2.
Learn the location
and function of epithelial tissue
On the lab practical you will be asked to
recognize tissues under the microscope. Quiz yourself or another student by blindly selecting
slides and identifying each one.
Exercise 6: Classification of
Exercise 6 is long and detailed,
covering 19 types of tissue.
Exercise 6 will be completed
over two lab periods. During Lab 2 you should learn the basic structure of epithelial
and the histology,
location, and function of the
3. Simple columnar
6. Stratified cuboidal e.t.
7. Stratified columnar e.t.
In Lab 3 we will study connective tissues.
Epithelial tissues cover surfaces including the lining of the stomach,
the lining of ducts, and the skin. Epithelial tissues
are named according to two structural characteristics:
1. Number of cell layers
2. Cell shape
For example, simple
cuboidal e.t. has one cell layer thick (simple) with cube shaped cells
(cuboidal). Stratified squamous e.t. has
multiple cell layers (stratified) with flattened, irregularly shaped cells
Two types of epithelial tissue,
pseudostratified columnar e.t.
and transitional e.t., seemingly defy this classification scheme. Pseudostratified columnar e.t. is a simple
tissue (one cell layer thick) and the cells are columnar in shape. The height
of the cells and the location of the nuclei within the cells give the appearance of multiple cell layers. Hence the name pseudostratified.
Transitional e.t. is a stratified tissue (multiple cell layers thick),
but the shape of the cells varies from squamous to cuboidal. As cells progress from the basement membrane
to the apical surface, there is a transition
in cell shape, from squamous to cuboidal.
Exercise 7: The Integument
The skin has two distinct layers.
1. The superficial epidermis is composed of stratified squamous e.t.
2. The deeper dermis consists
of dense irregular connective tissue (2nd half of Ex. 6) and several structures
including glands and hair follicles. Both
the dermis and the epidermis may, themselves,
be broken down into several layers.
Use Figs. 7.1 and 7.2 and prepared slides to learn them.
Stratum corneum (superficial)
microscope pointer to practice
identifying layers. Note: in most
of our slides, only the deepest and most
superficial layers of the epidermis
are clearly distinguishable (S.
basale and S. corneum, respectively).
You will not be asked to identify
any of the central
layers, but know them all, in order.
Within the dermis,
examine exocrine and apocrine glands as well as hair follicles.
Skip: Figs. 7.3,
7.4 (b) and (c), 7.5, and Plotting the
of Sweat Glands