Chapter 4. Epithelial Tissue

This chapter should help the student to:

• Name the four basic tissue types.
• Explain the characteristics that distinguish epithelial tissues from other basic tissue types.
• List the epithelial tissue types and give examples of sites where each may be found.
• Describe the functional capabilities of each epithelial tissue type and relate them to tissue structure.
• Describe the special functions of epithelial cell types and sites where each may be found.
• Recognize epithelia in micrographs and predict their function from their structure and location.
• List the criteria used to classify glands.
• List the classes of glands in humans and give examples of sites where each may be found.
• Recognize glands in micrographs or diagrams and identify gland types.

1. List the principal functions of epithelial tissues (II.A).

2. From which embryonic germ layer(s) are epithelial tissues derived? Give examples of epithelia derived from each (II.H; Table 4–1).

3. List the characteristics of epithelial tissues that distinguish them from other basic tissue types. Consider cell polarity (IV); specializations of the apical (IV.A), lateral (IV.B), and basal (IV.C) surfaces; nutrition (II.F); and mitotic rate (II.E).

4. Describe the basal lamina in terms of location, composition, and staining (IV.C.1.a).

5. Which structures and molecules help attach epithelial cells to their basal laminae (IV.C.1.a and 2) and to each other (IV.B.1-3)?

6. Compare basal laminae and basement membranes (IV.C.1.a).

7. Name four types of junctions found between epithelial cells (IV.B. 1-4).

8. Which junction(s) named in the answer to question 7 is (are) associated with:

1. A disklike structure (IV.B.3 and 4)?

2. A bandlike structure (IV.B.1 and 2)?

3. Plasma membrane fusion (IV.B.1)?

4. A sealing effect (IV.B.1)?

5. Cytokeratins (IV.B.2 and 3)?

6. Attachment plaques (IV.B.2 and 3)?

7. Connexons (IV.B.4)?

8. Integrins (IV.C.1.b and 2)?

9. Cadherins (IV.B.2 and 3)?

10. Microfilaments (IV.B.2 and C.1.b)?

11. Intermediate filaments (IV.B.3)?

12. Alpha-actinin (IV.B.2)?

9. Which junction is more important in cell-to-cell communication than cell–cell adhesion (IV.B.4)?

10. Compare microvilli, stereocilia, motile cilia, and flagella (IV.A.1–4) in terms of:

1. Width and length

2. The presence of a plasma membrane covering

3. The presence of microtubules or microfilaments

4. Motility

5. The presence of axonemes and basal bodies

6. Function and location in the body

11. List the types of simple and stratified epithelia and give examples of their locations (III.B.1–8).

12. Compare endocrine and exocrine glands in terms of their embryonic origins and how their products are transported (V.A; Table 4–3).

13. What structural criteria are used to classify exocrine glands (Table 4–5)?

14. Compare merocrine, holocrine, and apocrine secretion in terms of the part of the cell released, and give an example of each type of gland (Table 4–4).

15. Describe the structural modifications and staining properties ...