Anatomy and Physiology - Histology and Tissues

Flashcards covering tissue types, epithelial characteristics, classification of epithelia, glandular secretions, connective tissue components, muscle types, nervous tissue, membranes, and tissue repair based on Marieb Chapter 4.

Histology

The scientific study of tissues.

Tissues

Groups of cells that are similar in structure and perform a common or related function.

Fixed

A process in microscopy where tissue is preserved with a solvent.

Sectioned

A process in microscopy where tissue is cut into slices thin enough to transmit light or electrons.

Stained

The process of using colored dyes in light microscopy or heavy metal salts in electron microscopy to enhance contrast.

Artifacts

Distortions in microscopy samples that detract from what the sample looks like in living tissues.

Transmission electron microscopy (TEM)

A type of microscopy used to show a section of a tissue sample.

Scanning electron microscopy (SEM)

A type of microscopy used to show the surface of a tissue sample.

Epithelial tissue

A sheet of cells that covers a body surface or lines a body cavity.

Apical surface

The upper free side of epithelial tissue that is exposed to a surface or cavity.

Basal surface

The lower attached side of epithelial tissue that faces inwards toward the body and attaches to the basal lamina.

Basal lamina

An adhesive sheet that holds the basal surface of epithelial cells to underlying cells.

Microvilli

Specialized fingerlike projections often found on apical surfaces of epithelial cells.

Tight junctions

Specialized lateral contact points that bind adjacent epithelial cells together to form continuous sheets.

Reticular lamina

A layer deep to the basal lamina that consists of a network of collagen fibers.

Basement membrane

A structure made up of the basal and reticular lamina that reinforces the epithelial sheet and defines the epithelial boundary.

Avascular

A characteristic of tissue, such as epithelium, that contains no blood vessels.

Simple epithelia

Epithelial tissues consisting of a single cell layer, typically located where a thin barrier is desirable.

Stratified epithelia

Epithelial tissues consisting of two or more cell layers, typically located in high-abrasion areas.

Squamous cells

Epithelial cells that are flattened and scale-like.

Cuboidal cells

Epithelial cells that are box-like or cube-shaped.

Columnar cells

Epithelial cells that are tall and column-like.

Endothelium

A special type of simple squamous epithelium that lines lymphatic vessels, blood vessels, and the heart.

Mesothelium

A special type of simple squamous epithelium found in serous membranes in the ventral body cavity.

Goblet cells

Unicellular glands that secrete mucus, commonly found in simple columnar or pseudostratified epithelia.

Pseudostratified columnar epithelium

A single layer of cells of differing heights that appears to be multi-layered, often ciliated, and involved in mucus secretion.

Keratinized cells

Cells found in the stratified squamous epithelium of the skin that contain keratin and are dead at the surface.

Transitional epithelium

A type of stratified epithelium lining hollow urinary organs that can change shape when stretched to allow for increased urine flow or storage.

Gland

One or more cells that make and secrete an aqueous fluid called a secretion.

Endocrine glands

Ductless glands that produce hormones and release them into the surrounding interstitial fluid for transport via blood or lymph.

Exocrine glands

Glands that secrete their products onto body surfaces or into body cavities, often through ducts.

Mucin

A sugar-protein produced by unicellular exocrine glands that dissolves in water to form mucus.

Merocrine glands

Glands that secrete products by exocytosis as they are produced, such as the pancreas and most sweat glands.

Holocrine glands

Glands that accumulate products within until they rupture, such as sebaceous (oil) glands.

Apocrine glands

Glands that accumulate products within but only the apex ruptures, with mammary glands being the closest human example.

Extracellular matrix

The nonliving portion of connective tissues that supports cells, allowing them to bear weight and withstand tension.

Mesenchyme

The common embryonic tissue from which all connective tissues arise.

Ground substance

An unstructured gel-like material filling the space between cells in connective tissue, serving as a medium for solute diffusion.

Collagen fibers

The strongest and most abundant fiber type in connective tissue, providing high tensile strength.

Elastic fibers

Networks of long, thin elastin fibers that allow for stretch and recoil in connective tissue.

Reticular fibers

Short, fine, highly branched collagenous fibers that form networks offering more give than collagen fibers.

Blast cells

Immature forms of cells that actively secrete ground substance and matrix fibers.

Cyte cells

Mature forms of cells that maintain the health of the matrix.

Mast cells

Connective tissue cells that detect foreign microorganisms and initiate local inflammatory responses using heparin, histamine, and proteases.

Macrophages

Cells that break down foreign materials and dead cells through phagocytosis.

Areolar connective tissue

The most widely distributed connective tissue that supports and binds other tissues and serves as universal packing material.

Adipocytes

Cells specialized for the storage of energy as fat.

Stroma

A mesh-like framework formed by reticular fibers that supports blood cells in lymph nodes, spleen, and bone marrow.

Dense regular connective tissue

Tissue with high tensile strength featuring closely packed bundles of collagen fibers running parallel to the direction of pull.

Lacunae

Small cavities in the matrix of cartilage or bone where chondrocytes or osteocytes reside.

Hyaline cartilage

The most abundant type of cartilage, appearing as shiny bluish glass and found at the tips of long bones, the nose, and the trachea.

Osteons

Individual structural units of bone tissue.

Osseous tissue

Another name for bone tissue, which supports and protects body structures.

Blood plasma

The fluid matrix surrounding blood cells.

Intercalated discs

Specialized joints where cardiac muscle cells are joined together.

Neurons

Specialized nervous tissue cells that respond to stimuli and transmit electrical signals.

Neuroglia

Supporting cells in nervous tissue that support, insulate, and protect neurons.

Cutaneous membrane

Another name for the skin, consisting of keratinized stratified squamous epithelium attached to a thick layer of connective tissue.

Lamina propria

A layer of loose connective tissue lying under the epithelial sheet of a mucous membrane.

Serosae

Moist membranes found in closed ventral body cavities, constructed from simple squamous epithelium resting on areolar connective tissue.

Regeneration

A method of tissue repair where the same kind of tissue replaces destroyed tissue, restoring original function.

Fibrosis

A method of tissue repair where connective tissue replaces destroyed tissue, resulting in a loss of original function.

Granulation tissue

New capillary-enriched tissue that replaces a blood clot during the organization phase of tissue repair.

Ectoderm

The embryonic germ layer from which nervous tissue and some epithelial tissues arise.

Mesoderm

The embryonic germ layer from which muscle, connective tissues, and some epithelial tissues arise.

Endoderm

The embryonic germ layer from which some epithelial tissues arise.