Lab 2: Epithelial Tissues

Vocabulary practice flashcards covering basic tissue types, epithelial characteristics, classification, and specific epithelial tissue descriptions, functions, and locations.

Tissue

Groups of cells similar in structure that perform a common or related function.

Histology

The study of tissues.

Epithelial tissue

A primary tissue type that covers body surfaces, lines cavities and hollow organs, forms boundaries, protects, secretes, absorbs, and filters.

Connective tissue

A primary tissue type that supports, protects, and binds other tissues together.

Muscle tissue

A primary tissue type that contracts to produce movement.

Nervous tissue

A primary tissue type that acts as an internal communication, control, and integration center.

Apical surface

The upper free surface of epithelial tissue that is exposed to the exterior or an internal body cavity.

Basal surface

The lower, attached surface of epithelial tissue.

Microvilli

Cellular extensions on the apical surface of most epithelial tissues that increase surface area, such as the brush border of the intestinal lining.

Cilia

Hair-like structures located on the apical surface of certain epithelial cells, such as the lining of the trachea, that help propel substances.

Basement membrane

A structure supported by connective tissue that defines the epithelial boundary and reinforces the epithelial sheet.

Avascular

Lacking blood vessels; a characteristic of epithelial tissue where nutrients are supplied by blood vessels in underlying connective tissue.

Innervated

Supplied by nerve fibers.

Simple epithelia

Epithelial tissues consisting of a single layer of cells.

Stratified epithelia

Epithelial tissues consisting of two or more layers of cells.

Squamous cells

Flattened and scale-like cells with a flattened nucleus.

Cuboidal cells

Boxlike cells with a round nucleus.

Columnar cells

Tall, column-shaped cells with an elongated nucleus.

Simple squamous epithelium

Description: Single layer of flattened cells with disc-shaped central nuclei and sparse cytoplasm. Function: Allows materials to pass by diffusion and filtration where protection is not important; secretes lubricating substances in serosae. Location: Kidney glomeruli; air sacs of lungs; lining of heart, blood vessels, and lymphatic vessels; serosae.

Simple cuboidal epithelium

Description: Single layer of cubelike cells with large, spherical central nuclei. Function: Secretion and absorption. Location: Kidney tubules; ducts and secretory portions of small glands; ovary surface.

Simple columnar epithelium

Description: Single layer of tall cells with round to oval nuclei, often bearing microvilli or cilia, and may contain goblet cells. Function: Absorption; secretion of mucus, enzymes, and other substances; ciliated type propels mucus or reproductive cells. Location: Nonciliated type lines most of the digestive tract, gallbladder, and excretory ducts; ciliated variety lines small bronchi, uterine tubes, and regions of the uterus.

Goblet cells

Mucus-secreting unicellular glands contained within epithelial tissues such as simple columnar and pseudostratified columnar epithelia.

Pseudostratified columnar epithelium

Description: Single layer of cells of differing heights, some not reaching the free surface, with nuclei seen at different levels; may contain mucus-secreting cells and bear cilia. Function: Secrete substances, particularly mucus; propulsion of mucus by ciliary action. Location: Ciliated variety lines the trachea and most of upper respiratory tract; nonciliated type in males' sperm-carrying ducts and ducts of large glands.

Stratified squamous epithelium

Description: Thick epithelium composed of several cell layers; basal cells are cuboidal or columnar and active in mitosis, while surface cells are flattened. Function: Protects underlying tissues in areas subjected to abrasion. Location: Nonkeratinized type forms moist linings of esophagus, mouth, and vagina; keratinized variety forms the epidermis of the skin.