EPITissue Level of Organization Vocabulary

Comprehensive vocabulary flashcards covering tissue classifications, cellular junctions, epithelial tissue types, and glandular secretion mechanisms based on Chapter 4.

Tissue

Cells that work together to perform a specific function.

Histology

The study of tissues.

Organ

multiple tissues coming together to perform the same function.

Tight Junction

A fluid-sealed cell junction that keeps fluid from entering between cells.

Desmosome

A cell junction that acts as spot welding to hold cells together.

Gap Junction

A communicating cell junction that allows chemicals to move between cells.

Avascular

Lacking blood vessels

Basement Membrane

A structure composed of collagen and glycoproteins that attaches epithelium to underlying connective tissue, permits mitosis, and regulates permeability.

Keratin

A strong protective protein that makes epithelial tissue tough and dry when present,

Cilia

Hair-like projections on epithelial cells that function to trap mucus and move particles.

Goblet Cell

An exocrine gland that produces and secretes mucin or mucus for protection and lubrication.

Simple Epithelium

Epithelial tissue characterized by having a single layer of cells.

Stratified Epithelium

tissue composed of more than one layer of cells, named based on the shape of the cells at the free surface.

Simple Squamous Tissue

An epithelium consisting of one layer of flat cells that provides a thin barrier for diffusion; lines blood vessels, body cavities, air sacs, and kidney tubules.

Endothelium

A type of simple squamous tissue that lines the heart, blood vessels, and lymphatic vessels.

Mesothelium

A specialized type of simple squamous tissue that lines body cavities.

Simple Cuboidal Tissue

An epithelium consisting of one layer of cuboidal cells involved in secretion and absorption; located in ducts, glands, kidney tubules, and the thyroid gland.

Simple Columnar Tissue

An epithelium consisting of one layer of tall cells involved in secretion and absorption; lines most of the gastrointestinal tract, fallopian tubes, and larger ducts.

Microvilli

Structures present on the free surface of columnar epithelial cells in the digestive tract that increase surface area to allow more nutrient absorption.

Stratified Squamous Tissue

An epithelium with several layers where superficial cells are flat; provides protection in the skin, mouth lining, esophagus, vagina, and rectum.

Transitional Epithelium

Epithelial tissue made of differently shaped cells that change shape (flattened when stretched, round when relaxed) to allow organs like the ureters and bladder to expand.

Pseudostratified Epithelium

Epithelial tissue that appears stratified but has every cell touching the basement membrane; lines the respiratory tract and parts of the male reproductive tract.

Exocrine Gland

A gland composed of epithelial tissue that has ducts to carry its secretions to a surface.

Endocrine Gland

A gland composed of epithelial tissue that lacks ducts and releases hormones directly into the blood.

Holocrine Gland

A multicellular exocrine gland that releases its secretion by breaking down the whole cell.

Merocrine Gland

a type of exocrine gland that releases secretions from vesicles through exocytosis

Apocrine Gland

A multicellular exocrine gland that releases its secretion by shedding cytoplasm and a top portion of the free surface.