12.1.3 Animal Tissues: Epithelial Tissue

Question 1

Animal Tissues: Epithelial Tissue

Answer 1

• Tissue is an interrelated system of cells that serve a common function within the body and have similar structure.
• There are four types of tissue in animals: epithelial, connective, muscle, and nervous tissue.
• Epithelial tissue is mostly cellular, avascular, highly mitotic, and it has one cell layer exposed to the environment. It functions as protection, to control permeability and for secretion.
• There are three major groups of epithelial tissue: squamous, cuboidal, and columnar.

Question 2

epithelial tissue

Answer 2

• Within each type of tissue, structure follows function. The functions of epithelial tissues include protection, control of permeability, and secretion.
• Epithelial tissue, illustrated to the left, is a tissue comprised mostly of cells, as opposed to other tissues that have components other than cells. Epithelial tissues have one surface that is always exposed to the environment. Since the cells of epithelial tissues are exposed to the environment, they are constantly dividing to replenish themselves.
• Epithelial tissues are avascular, they lack blood vessels) and are connected at the bottom by a basement membrane. Cells of epithelial tissues are adjoined to each other by connections such as tight junctions, gap junctions, and desmosomes.

Question 3

Simple squamous epithelial tissue

Answer 3

• is one cell layer thick and facilitates diffusion. It is found in the alveoli of the lungs.

Question 4

Stratified squamous epithelial tissues

Answer 4

• are many cell layers thick and function in protection. Examples include the lining of the esophagus and skin.

Question 5

simple cuboidal epithelial tissue

Answer 5

• The cells have a cuboid shape, resulting in an increased volume. This tissue functions in secretion and is found in glands such as the salivary gland and the thyroid gland.

Question 6

Stratified cuboidal tissue

Answer 6

• is cuboid in shape and has multiple cell layers. It functions in both secretion and protection and is found in sweat glands and the thyroid gland

Question 7

Simple columnar epithelial tissue

Answer 7

• is composed of long column-like cells that are large in volume and a single cell layer thick. It functions in the secretion of large amounts of enzymes and is found lining the stomach.

Question 8

Pseudostratified columnar epithelial tissue

Answer 8

• is composed of large irregularly layered cells that have microvilli along one side. They function in absorption and are found lining the nasal passages and respiratory surfaces.

Question 9

Stratified columnar epithelial tissue

Answer 9

• is multiple cell layers thick and composed of cells that have a large volume. It functions in secretion and protection and are found in the urethra, mouth, and the epiglottis.

Question 10

Epithelial tissues function in

Answer 10

• protection
• permeability
• secretion

Question 11

What are the four main types of tissue in animals?

Answer 11

• epithelial, connective, muscle, and nervous

Question 12

Which of the following is a characteristic of epithelial tissue?

Answer 12

• high rate of mitosis

Question 13

Which type of epithelial tissue is in the alveoli of the lungs?

Answer 13

• simple squamous

Question 14

The top of epithelial cells is exposed to air or fluid, while the bottom is

Answer 14

• attached to a basement membrane.

Question 15

____________ epithelial tissue is composed of irregularly layered cells, which have microvilli on one side. They function in absorption.

Answer 15

• pseudostratified columnar