Molecular Biology: Epithelium

These flashcards cover key concepts from the Biology 460 lecture on epithelium, including types of epithelium, their functions, and structural characteristics.

What are the four basic tissue types that make up the human body?

Epithelial, Connective, Muscular, and Nervous tissue.

What is epithelium?

A sheet of cells that covers a body surface or lines a body cavity and forms most of the body’s glands.

List the functions of epithelial tissue.

Protection, Absorption, Sensory reception, Ion transport, Secretion, Filtration, and Formation of slippery surfaces for movement.

What is the defining characteristic of simple epithelium?

Simple epithelium consists of a single layer of cells.

Differentiating factor of stratified epithelium?

Stratified epithelium consists of more than one layer of cells.

How are epithelial cells classified based on shape?

They can be classified as squamous, cuboidal, or columnar.

What is the role of the basement membrane in epithelial tissue?

The basement membrane supports the epithelial tissue and separates it from the underlying connective tissues.

Name the two types of glands classified based on secretion.

Exocrine and Endocrine glands.

What is the primary difference between endocrine and exocrine glands?

Endocrine glands are ductless and release hormones into the bloodstream, while exocrine glands discharge secretions via ducts onto epithelial surfaces.

What is histology?

The microscopic study of cells, tissues, and organs to understand the relationship between structure and function.

Describe the structure of simple squamous epithelium.

A single layer of flat cells with a centrally located flattened nucleus.

Where can simple cuboidal epithelium be found?

In the pigmented layer of the retina, surface of the ovary, ducts of glands, and kidneys.

What modifications might you find on the apical surface of epithelial cells?

Cilia and Microvilli.

What type of epithelial tissue would you find lining the respiratory tract?

Pseudostratified columnar epithelium.

What type of epithelium is associated with stretching and found in the urinary tract?

Transitional epithelium.

What are the components of cell junctions?

Tight junctions, adherens junctions, desmosomes, hemidesmosomes, and gap junctions.

What is the function of microvilli in epithelial tissue?

Microvilli increase surface area for absorption.

Differentiate between merocrine, apocrine, and holocrine glands.

Merocrine glands secrete via exocytosis, apocrine glands release lipid products via membrane-bound vesicles, and holocrine glands discharge entire secretory cells.

What is meant by the term 'cellularity' in relation to epithelial tissue?

Cellularity refers to the high density of cells in epithelial tissues, with minimal extracellular matrix.

What type of epithelial cells are typically found in the glands of the body?

Epithelial cells can be unicellular or multicellular and function in the secretion of substances.