CH4 - TISSUES PT1 -Epithelial Tissue (Epithelium)

Vocabulary flashcards covering key terms related to tissues, epithelial tissue, basement membrane, glandular tissue, and secretion types as described in the notes.

Tissue

A group of cells that work together with a common function.

Histology

The study of tissues.

Epithelial tissue (epithelium)

Tissue that covers surfaces or lines cavities; tightly packed; avascular; has apical (free) and basal surfaces; rests on a basement membrane; can form glands.

Basement membrane

Protein and glycoprotein layer secreted by epithelium and connective tissue that connects epithelium to underlying connective tissue and supports regeneration and diffusion control.

Avascular

Characteristic of epithelial tissue that lacks blood vessels; nutrients come from underlying connective tissue through the basement membrane.

Apical surface

The free surface of an epithelium facing the air or a body cavity.

Basal surface

Surface of an epithelium that rests on the basement membrane and connects to the connective tissue.

Desmosome

A cell junction that welds adjacent cells together to resist tearing.

Tight junction

A junction that seals the space between cells, preventing fluid passage.

Gap junction

A channel-forming junction that allows direct communication between neighboring cells.

Simple epithelium

Epithelium with a single cell layer.

Stratified epithelium

Epithelium with two or more cell layers.

Squamous

Flat, scale-like cells.

Cuboidal

Cube-shaped cells.

Columnar

Tall, column-shaped cells.

Simple squamous tissue

One layer of flat cells; ideal for diffusion; found in lungs (alveoli) and lining blood vessels (endothelium).

Endothelium

Simple squamous tissue that lines the inside of blood vessels.

Mesothelium

Simple squamous tissue that lines the thoracic and abdominal cavities (peritoneum, pleura, and pericardium).

Simple cuboidal tissue

One layer of cube-shaped cells; involved in secretion and absorption; common in kidney tubules.

Simple columnar tissue

One layer of tall, column-like cells; often lines the digestive tract; involved in absorption and secretion.

Stratified squamous tissue

Multiple layers of cells; provides protection; found in the mouth, esophagus, vagina, and around the anus.

Stratified cuboidal tissue

Stratified tissue with cuboidal cells; not very common; lines some ducts.

Stratified columnar tissue

Stratified tissue with columnar cells; not very common; lines some ducts.

Pseudostratified epithelium

Looks multi-layered but all cells touch the basement membrane; often ciliated; lines the respiratory tract; contains goblet cells.

Transitional epithelium

Epithelium that can stretch and change shape; lines the bladder and urinary tract.

Goblet cell

A unicellular mucus-secreting gland; mucus protects and lubricates; common in pseudostratified and columnar epithelia.

Glandular tissue

Epithelium-derived tissue that forms glands, including exocrine and endocrine glands.

Exocrine gland

Gland that secretes onto a surface through ducts; often lined by simple cuboidal epithelium.

Endocrine gland

Gland that secretes hormones directly into the bloodstream.

Merocrine secretion

Secretory product released by exocytosis without loss of cytoplasm; e.g., sweat glands.

Apocrine secretion

Secretory product collects at the apex and a portion of the cell pinches off; e.g., mammary glands.

Holocrine secretion

Whole cell disintegrates to release its secretory product; the cell is replaced by a new one.