Histology Vocab

Physiology H

free surface

uppermost row of cells adjacent to the passageway of the structure

basement membrane

tissue to which the last row of epithelial tissue cells are attached

cell conections

mechanically binds cells together, helps form a permeability barrier, provides a mechanism for intercellular communication

desmosomes

disk shaped structures with adhesive glycoproteins that bind cells to one another

hemidesmosomes

attach cells to basement membrane

tight junctions

holds cells together to form a permeability barrier; consists of zonula adherens and zonula occludents

zonula adherens

actin protein filaments-fine fibers; located between cell membrane of adjacent cells and act as a weak glue that holds cells together

zonula occuldens

forms a permeability barrier; they prevent the passage of materials between cells, forms a jigsaw arrangement to form a tight seal (tubular)

gap junctions

a small protein channel that provides a means of intercellular communication by allowing a passage of ion and small molecules between cells

glands

secretory organs; most are compromised of epithelial tissue cells with a supporting network of connective tissue

exocrine glands

glands with ducts; ducts lines with epithelial tissue

endocrine glands

glands that have no ducts; produce hormones which are secreted into bloodstream

merocrine glands

water producing sweat glands; they secrete products with no loss of cellular material

apocrine glands

discharges fragments of the gland cells in secretion; cell fragments pinch off ex: milk producing mammary glands

halocrine glands

shed entire cells; entire cell becomes part of secretion ex: sebaceous (oil) glands

matrix

background material of the connective tissue. and is made up of protein fibers, a ground substance consisting of non-fibrous protein and fluid

collagen fibers

most common protein in the body; appears like rope and is very strong

reticular fibers

very fine collagen fibers; thin, short and branching; not very strong but fills the space between tissue and organs

elastic fibers

contains elastin; enables tissue to be distended or compressed. Long and web like fibers

blasts

young healthy cells that create the matrix

cytes

mature cells that maintain the matrix

ground substance

the shapeless background material of the matrix