Tissues and Histology Flashcards

Flashcards covering tissue types, epithelial characteristics and classification, cell modifications, and connective tissue classification and features.

Epithelial tissue

Tissue that covers exposed surfaces, lines internal passageways and chambers, and produces glandular secretions.

Connective tissue

Tissue that fills internal spaces, provides structural support, and stores energy.

Muscle tissue

Tissue that contracts to produce active movement.

Neural tissue

Tissue that conducts electrical impulses and carries information.

Cellularity

A characteristic of epithelial tissue in which it is composed almost entirely of cells bound together by intercellular junctions.

Epithelial Polarity

The structural organization of epithelial cells having an apical surface on top and a basal surface at the bottom.

Avascular

Lacking blood vessels, forcing epithelial cells to receive nutrients by diffusion from underlying tissues.

Simple epithelium

An epithelial tissue layer consisting of only one layer of cells.

Stratified epithelium

An epithelial tissue layer consisting of more than one layer of cells.

Squamous cells

Epithelial cells that are wider than tall and plate-like in shape.

Cuboidal cells

Epithelial cells that are as wide as tall, shaped like cubes.

Columnar cells

Epithelial cells that are taller than they are wide, shaped like columns.

Cilia

Apical surface modifications of epithelial cells responsible for moving substances, commonly found in the respiratory system.

Microvilli

Apical surface modifications of epithelial cells that greatly increase absorptive surface area, commonly found in the digestive tract.

Simple Columnar Epithelium

Epithelium composed of a single layer of tall cells, located in digestive tract structures such as the stomach, small intestine, and large intestine.

Simple Cuboidal Epithelium

Epithelium composed of a single layer of cube-shaped cells, located in glandular tissue such as the kidney or thyroid.

Simple Squamous Epithelium

Epithelium composed of a single layer of flattened, plate-like cells, located in places such as the alveoli of the lungs.

Fibroblasts

Connective tissue cells that secrete matrix proteins.

Ground substance

A mixture of proteins and carbohydrates with variable amounts of salts and water that forms part of the matrix of loose connective tissue.

Extracellular matrix

The non-cellular component of connective tissue comprised of protein fibers and ground substance.

Collagen fibers

The thickest and strongest connective tissue fibers that give resilience and strength to ligaments and tendons.

Elastic fibers

Connective tissue fibers that stretch easily, branch, and rejoin, allowing structures like blood vessels to stretch and relax.

Reticular fibers

Thin connective tissue fibers forming a branching woven network that supports soft organs like the liver, lymph nodes, and spleen.

Areolar Tissue

A loose connective tissue surrounding blood vessels, nerve bundles, muscles, and organs that cushions organs and permits independent movement.

Adipose Tissue

A loose connective tissue dominated by adipocytes that provides padding, cushions shocks, insulates against heat loss, and stores energy.

Reticular Tissue

Loose connective tissue consisting of an open framework of reticular fibers that provides a supporting framework for soft organs.

Dense Regular Connective Tissue

Connective tissue proper consisting primarily of parallel collagen fibers that provides firm attachment and conducts muscle pull in tendons and ligaments.

Dense Irregular Connective Tissue

Connective tissue proper consisting primarily of irregularly arranged collagen fibers that withstands tension in many directions, found in the dermis and organ capsules.

Dense Elastic Connective Tissue

Dense connective tissue containing a high proportion of elastic fibers allowing recoil after stretching, located in the walls of the aorta and ligamentum flavum.