Chapter 20 Key Terms Flashcards
Cell junction that helps hold together epithelial cells in a sheet of epithelium; actin filaments inside the cell attach to its cytoplasmic face.
Adherens junction
Describes the top or the tip of a cell, structure, or organ; in an epithelial cell, for example, this surface is opposite the base, or basal surface.
Apical
Situated near the base; opposite of apical.
Basal
Thin mat of extracellular matrix, secreted by epithelial cells, upon which the cells sit.
Basal lamina
A member of a family of Ca+2 dependent proteins that mediates the attachment of one cell to another in animal tissues.
Cadherin
Disease caused by abnormal and uncontrolled cell proliferation, followed by invasion and colonization of body sites normally reserved for other cells.
Cancer
Specialized region of connection between two cells or between a cell and the extracellular matrix.
Cell junction
Mechanically strong fibrous layer deposited by a cell outside its plasma membrane. Prominent in most plants, bacteria, algae, and fungi, but not present in most animal cells.
Cell wall
Long, thin strand of cellulose that helps strengthen plant cell walls.
Cellulose microfibril
Triple-stranded, fibrous protein that is a major component of the extracellular matrix and connective tissues; it is the main protein in animal tissues, and different forms can be found in skin, tendon, bone, cartilage, and blood vessels.
Collagen
Tissues such as bone, tendons, and the dermis of the skin, in which extracellular matrix makes up the bulk f the tissue and carries the mechanical load.
Connective tissue
Specialized cell-cell junction, usually formed between two epithelial cells, that serves to connect the ropelike keratin filaments of the adjoining cells, providing tensile strength.
Desmosomes
An undifferentiated cell type derived from the inner cell mass of an early mammalian embryo and capable of differentiating to give rise to any of the specialized cell types in the adult body.
Embryonic stem (ES) cell
Complex network of polysaccharides (such as glycosaminoglycans or cellulose) and proteins (such as collagen) secreted by cells. A structural component of tissues that also influences their development and physiology.
Extracellular matrix
Cell type that produces the collagen-rich extracellular matrix in connective tissues such as skin and tendon. Proliferates readily in wounded tissue and in tissue culture.
Fibroblast
In animal tissues, specialized connection between juxtaposed cells through which ions and small molecules can pass from one cell to the other.
Gap junction
Structure that anchors epithelial cells to the basal lamina beneath them.
Hemidesmosome
Family of transmembrane proteins present on cell surfaces that enable cells to make and break attachments to the extracellular matrix, allowing them to crawl through a tissue.
Integrin
Cell-cell junction that connects one plant cell to the next; consits of a channel of cytoplasm lined by membrane.
Plasmodesma (plural plasmodesmata)
Cell-cell junction that seals adjacent epithelial cells together, preventing the passage of most dissolved molecules from one side of the epithelial sheet to the other.
Tight junction
Cooperative assembly of cells and matrix woven together to form a distinctive multicellular fabric with a specific function.
Tissue
Extracellular matrix protein that helps cells attach to the matrix by acting as a “linker” that binds to a cell-surface integrin molecule on one end and to a matrix component, such as collagen, on the other.
Fibronectin
An increased rate of mutation often caused by defects in the systems that govern the accurate replication and maintenance of the genome; the resulting mutations sometimes drive the evolution of cancer.
Genetic instability
Polysaccharide chain that can form a gel that acts as a “space filler” in the ECM of connective tissues; helps animal tissues resist compression.
Glycosaminoglycan (GAG)
