Epithelial Tissues
Laboratory Exercise 7
Background
Epithelial tissues are tightly packed single (simple) to multiple (stratified) layers of cells that
provide protective barriers. The underside of this tissue layer contains a basement
membrane layer to which the epithelial cells anchor. Epithelial cells always have a free
surface that is exposed to the outside or to an open space internally. Many shapes of the
cells exist that are used to name and identify the variations. Many of the prepared slides
contain more than the tissue to be studied, so be certain that your view matches the correct
tissue. Also be aware that stained colors of all tissues might vary.
Materials Needed
Textbook
Compound light microscope
Prepared slides of the following:
Simple squamous epithelium
Simple cuboidal epithelium
Simple columnar epithelium
Pseudostratified columnar epithelium
Stratified squamous epithelium
Transitional epithelium
Purpose of the Exercise
Review the characteristics of epithelial tissues and observe examples of each type.
Procedure
1. Complete Part A .
2. Use the microscope to observe the prepared slides of the types of epithelial tissues.
View under high power (400x). Compare your prepared slides to the micrographs at the
front of the room. Note that some of the tissue colors may vary with the
stain.
3. Complete Part B. Make a sketch of each tissue and label the following: basement
membrane, nucleus, and any other distinguishing characteristic (goblet cell, cilia,
microvilli).
Part A
Match the tissue type with the characteristics. Place the letter of your choice in the space
provided. (Some answers will be used more than once.)
___ 1. Consists of several layers of cube-shaped, elongated, and irregular cells.
___ 2. Commonly possesses cilia that move sex cells and mucus.
___ 3. Single layer of flattened cells.
___ 4. Nuclei located at different levels within cells.
___ 5. Forms walls of capillaries and air sacs (alveoli) of lungs.
___ 6. Forms linings of trachea and bronchi.
___ 7. Younger cells are cuboidal and older cells are flattened.
___ 8. Forms inner lining of urinary bladder.
___ 9. Lines kidney tubules and ducts of salivary glands.
___10. Forms lining of stomach and intestines.
___11. Nuclei located near basement membrane.
___12. Forms lining of oral cavity, anal canal, and vagina.
a. Simple squamous epithelium
b. Simple cuboidal epithelium
c. Simple columnar epithelium
d. Pseudostratified columnar epithelium
e. Stratified squamous epithelium
f. Transitional epithelium
Part B
Sketch each type of epithelial tissue in the spaces provided. Indicate their function and
their location within the body.
Simple squamous epithelium (400x)
Location _______________
Function _______________
Simple columnar epithelium (400x)
Location _______________
Function _______________
Simple cuboidal epithelium (400x)
Location _______________
Function _______________
Pseudostratified columnar epithelium (400x)
Location _______________
Function _______________
Stratified squamous epithelium (400x)
Location _______________
Function _______________
Transitional epithelium (400x)
Location _______________
Function _______________
Critical Thinking Application
As a result of your observations of epithelial tissues, which one(s) provide(s) the best
protection? Explain your answer.