Unit 5 – Tissue Structure I 1
Examples of Cells:
Epithelial Tissue Types: Unit 5 – Tissue Structure I 2
Objective 1 – Define cell specialization and describe its importance to an
All cells are similar early in development.
The body begins as a single fertilized egg, or cell. It divides and produces thousands of cells.
The cells eventually divide unevenly, producing a size difference, and then take on different shapes
Cell specialization – the tendency of a particular cell type to have a special shape or structure which is related to
the special functions the cell carries out.
Specialization first occurs during the embryonic and fetal development, but continuous as certain specialized cells
are produced by other non-specialized cells which are dividing.
Cell specialization increases the efficiency of the body. One cell cannot carry out all of the functions. With different
cell types for different functions, the speed and effectiveness of activities increases.
Objective 2 – Describe the general characteristics of each of the following cell
types and relate their characteristics to their functions.
- Conducts electrical impulse from one body part to another
- Has numerous processes around its body that receive impulses from another cell – a receptor cell or a
- the cell structure is very well suited for receiving and transmitting many impulses
- A muscle is designed to pull on a bone or to collapse a tube or sac
- In order to create this type of movement, a muscle cell is elongated, allowing maximum amount of
movements when the cell contracts.
Red Blood Cell (Erythrocyte)
- Major feature = no nucleus
o Suggests that RBC’s have reduced metabolism, thus using little oxygen
- FUNCTION = carries oxygen to different parts of the body
o Does not use the oxygen it carries
- Shape of the RBC (flattened) increases its surface area relative to its volume, allowing for greater
movement of gases across its surface
White Blood Cell (Leukocyte)
- Large and flexible so it can surround and ingest bacteria Unit 5 – Tissue Structure I 3
Objective 3 – Describe the structure and function of epithelial tissue.
Four Types of Tissues:
1. Epithelial 3. Muscular
2. Connective 4. Nervous
Epithelial tissue – lines and covers other tissues
Three basic cell types: squamous, cuboidal, and columnar
Simple form = one layer of cells
Stratified form = several layers of cells
Squamous epithelial tissue
Allows easy movement of materials across cell surface
Found where there will be an exchange of m