Tissues and Epithelial Cells

These flashcards cover key concepts related to tissue types and epithelial cells, including definitions and important characteristics.

Smooth muscle cell

A type of muscle cell that contracts involuntarily and is found in the walls of hollow organs.

Tissue level

Level of biological organization where similar types of cells group together to perform a specific function.

Epithelial tissue

A tissue composed of layers of cells that cover body surfaces and line cavities.

Basal surface

The surface of an epithelial cell that is attached to the underlying connective tissue.

Apical surface

The free surface of an epithelial cell that faces the body cavity or external environment.

Basement membrane

Thin, fibrous layer that provides support and anchorage for epithelial tissue.

Avascular

Lacking blood vessels; referring to epithelial tissue that receives nourishment through diffusion.

Keratinized stratified squamous epithelium

Epithelial tissue that has multiple layers, with the superficial cells being dead and filled with keratin.

Non-keratinized stratified squamous epithelium

Epithelial tissue that remains moist and has living cells in all layers, found in areas like the mouth and esophagus.

Transitional epithelium

Type of epithelium that can stretch and accommodate changes in volume, found in the urinary bladder.

Exocrine glands

Glands that secrete their products onto body surfaces or into body cavities through ducts.

Endocrine glands

Ductless glands that release hormones directly into the bloodstream.

Mucus

A viscous secretion produced by epithelial cells that serves to protect and lubricate surfaces.

Goblet cell

A unicellular exocrine gland that secretes mucus, commonly found in epithelial tissues.

Merocrine glands

Exocrine glands that secrete products via exocytosis without damaging the gland cells.

Apocrine glands

Glands that release secretions by pinching off a portion of their cytoplasm along with the product.

Holocrine glands

Glands that release their secretions by rupturing entire cells, resulting in the loss of all cell contents.

Simple epithelium

Epithelial tissue consisting of a single layer of cells.

Stratified epithelium

Epithelial tissue that consists of two or more layers of cells.