Epithelial Tissue and Its Classification

These flashcards cover the key vocabulary and concepts related to epithelial tissue and its classification as discussed in the lecture.

Epithelial Tissue

A type of tissue that covers body surfaces, lines cavities, and forms glands.

Basal Lamina

A thin layer of extracellular matrix that underlies epithelial tissue.

Basement Membrane

A structure that anchors epithelial tissues to the underlying connective tissue.

Microscopy

The use of microscopes to observe small-scale structures.

Simple Squamous Epithelium

A single layer of flat cells, typically found in areas where diffusion occurs such as alveoli.

Simple Cuboidal Epithelium

A single layer of cube-shaped cells, found in glands and kidney tubules.

Simple Columnar Epithelium

A single layer of tall cells, often found in digestive organs.

Pseudostratified Epithelium

A type of epithelium where cells appear stratified but are not; commonly found in the trachea.

Stratified Squamous Epithelium

Multiple layers of cells that protect underlying tissues; found in skin and mucous membranes.

Transitional Epithelium

A type of epithelium that can stretch, found in the urinary bladder.

Exocrine Glands

Glands that secrete substances through ducts to the surface of an organ.

Endocrine Glands

Glands that release hormones directly into the bloodstream.

Extracellular Matrix

A non-cellular component present in all tissues and organs, giving them structure and support.

Muscle Tissue

A type of tissue that is composed of contractile cells responsible for movement.

Connective Tissue

A type of tissue that provides support, binds other tissues, and fills spaces.

Nervous Tissue

Tissue responsible for the transmission of electrical impulses throughout the body.

Morphologic Classification

Classification based on structure, used for epithelial and connective tissues.

Functional Classification

Classification based on function, used for muscle and nerve tissues.

Cell Junctions

Specialized structures that form connections between epithelial cells.

Apical Domain

The upper free surface of an epithelial cell that often contains microvilli or cilia.

Basal Domain

The surface of epithelial cells that is anchored to the basement membrane.

Lateral Domain

The sides of epithelial cells that contain intercellular junctions.

Microvilli

Small projections that increase the surface area of epithelial cells, often aiding absorption.

Cilia

Hair-like structures that aid in movement across epithelial surfaces.

Desmosomes

Cellular junctions that mechanically attach adjacent cells.

Tight Junctions

Cell junctions that prevent the passage of molecules between epithelial cells.

Gap Junctions

Connections that allow for communication and ion passage between adjacent cells.

Lamina Densa

The dense layer of the basement membrane, important for structural support.

Hemidesmosomes

Cellular structures that anchor epithelial cells to the underlying basement membrane.

Cuboidal Cells

Cells that are as wide as they are tall, typically found in glands.

Columnar Cells

Tall and column-shaped cells, often involved in absorption and secretion.

Nervous Tissue Components

Includes neurons and neuroglial cells that support and protect neurons.

Neurons

Specialized cells that transmit electrical impulses.

Neuroglial Cells

Supporting cells that protect and support neurons.

Ectoderm

The outermost layer of embryonic tissue that forms the skin and nervous system.

Mesoderm

The middle layer of embryonic tissue that forms connective tissues and muscle.

Endoderm

The innermost layer of embryonic tissue that forms internal organs.

Glandular Epithelium

Composed of cells specialized for secretion.

Unicellular Glands

Glands made up of a single cell, such as goblet cells.

Multicellular Glands

Glands composed of multiple cells; can be further classified into exocrine and endocrine.

Merocrine Glands

Glands that secrete without losing cellular material.

Holocrine Glands

Glands that release entire cells filled with secretory product.

Apocrine Glands

Glands that lose part of their cell body during secretion.

Secretory Granules

Small membrane-bound vesicles that store secretion products in glandular cells.

Simple Tubular Glands

Glands with a straight duct and tubular secretory unit.

Compound Tubular Glands

Glands that have a branched duct structure with tubular secretory units.

Simple Alveolar Glands

Glands with a simple duct and a sac-like secretory unit.

Compound Alveolar Glands

Glands that have a branched duct structure with sac-like secretory units.

Salivary Glands

Glands that produce saliva, having both mucous and serous components.

Intestinal Glands

Glands present in the intestine that secrete digestive enzymes.

Pancreatic Glands

Glands that secrete hormones and digestive enzymes into the intestine.

Adrenal Glands

Endocrine glands that produce hormones like adrenaline.

Sebaceous Glands

Glands associated with hair follicles that secrete oil.