Microscope and Tissue Classification Vocabulary

Vocabulary terms and definitions covering histology, cell shapes, epithelial tissues, connective tissue types, body membranes, and microscopic anatomy.

Histology

The study of tissues.

Epithelial Tissue

A tissue that covers internal and external surfaces of your body, lines body cavities and hollow organs.

Simple Epithelium

Epithelial tissue consisting of 1 layer of cells.

Stratified Epithelium

Epithelial tissue consisting of 2 or more layers of cells.

Squamous Cell

A cell shape that is flat and squished, like a pancake.

Cuboidal Cell

A cube-shaped epithelial cell.

Columnar Cell

A column-shaped epithelial cell.

Simple Squamous Epithelium

A single layer of thin, flat cells that allows for rapid diffusion; found in the walls of capillaries and the air-exchanging alveoli of lungs.

Endothelial Cells

Simple squamous epithelial cells that form the walls of tiny capillaries.

Simple Cuboidal Epithelium

Single layer of cube-shaped cells located in the walls of renal tubules in kidneys; helps move substances between blood and tubular fluid through diffusion and active transport.

Renal Tubules

Small tubes in the kidneys that are part of the nephron and lined with simple cuboidal epithelium to help form urine.

Enterocytes

Absorptive simple columnar epithelial cells with microvilli on their apical surface, found lining the small intestine.

Simple Columnar Epithelium

Single layer of column-shaped cells lining the digestive tract that allows diffusion and active transport of nutrients into blood and lymph.

Goblet Cells

Simple columnar cells in the intestinal lining that secrete mucus to protect and lubricate the lining.

Stratified Squamous Epithelium

Epithelium with multiple cell layers containing abundant hydrophobic keratin/protein to form a barrier against water loss and bacteria invasion; located in the epidermis, mouth, and throat.

Loose Areolar Connective Tissue

A soft packaging tissue containing collagen, elastic, and reticular fibers located in the dermis, hypodermis, and around blood vessels, nerves, and organs.

Collagen Fibers

Thick, strong fibers in connective tissue that provide tensile strength.

Elastic Fibers

Thin, wavy fibers in connective tissue that allow stretch and recoil (flexibility).

Reticular Fibers

Very thin, branching fibers (type III collagen) that form a delicate supporting network (stroma) for cells.

Fibroblasts

Connective tissue cells with dark, elongated nuclei that produce fibers.

Dense Regular Connective Tissue

Connective tissue made of lots of collagen fibers going in the same direction, providing high strength in tendons and ligaments.

Tendons

Dense regular connective tissue structures that connect muscles to bone.

Ligaments

Dense regular connective tissue structures that connect bones to bones.

Dense Irregular Connective Tissue

Connective tissue with collagen fibers running in different directions to resist stretch and pull from many directions; located in the dermis and joint capsules.

Adipose Tissue

Fat tissue composed of adipocytes filled with triglycerides, located in the subcutaneous layer (hypodermis) for padding, energy, and storage.

Adipocytes

Fat cells containing a large vacuole filled with a fat droplet (triglycerides).

Mucous Membrane

Membrane that lines passageways or chambers open to the outside world, comprised of simple or stratified epithelium with underlying areolar tissue.

Serous Membrane

Membrane that lines internal body cavities and covers organs, comprised of mesothelium (simple squamous) and underlying areolar tissue.

Synovial Membrane

Membrane that lines joint capsules and produces synovial fluid, comprised of an incomplete epithelium and underlying areolar tissue.

Cutaneous Membrane

Membrane that covers the body surface (skin), comprised of keratinized stratified squamous epithelium with underlying areolar and dense irregular tissue.