Epithelia Flashcards
Epithelia are ________ meaning they depend on diffusion of nutrients from capillaries in the underlying connective tissue or from a moist free surface.
avascular
What are epithelia innervated by?
sensory neurons
What are the two surfaces that the layer(s) of epithelia attaches that form a flat sheet?
free surface and basal surface
Which surface is exposed to the environment or an internal body cavity?
free surface
Which surface is attached to a basement membrane?
basal membrane
What is the layer of collagen and adhesive proteins that anchors epithelium to underlying connective tissue? Is it permeable or semi-permeable?
basement membrane; semi-permeable
What two laminas is the basement membrane composed of?
basal lamina and reticular lamina
The _____ ______ is a complex mixture of proteins produced by epithelial cells and underlying fibroblasts
basal lamina
What are the 3 things the basal epithelial cells contributes to the basal lamina?
laminin, entactin, type IV collagen
________ in connective tissue under epithelia contribute molecules including _________ and __________ to the basal lamina.
Fibroblasts; fibronectin; proteoglycans
The _________ ______ is composed of a network of long straight collagen fiber and branched reticular fibers under the basal lamina.
reticular lamina
What underlying connective tissue does the reticular lamina blend into?
lamina propria
The _____ ______ is composed of a thin, light staining ______ ______ and a darker staining ______ _____.
basal lamina; lamina lucida; lamina densa
What is the electron-lucent layer above the lamina densa that contains extrecellular portions of cell adhesion molecules from the integrin family of transmembrance proteins including laminin, entactin, and fibronectin?
lamina lucida
_______ is a glycoprotein secreted by epithelial cells that bind Type IV collagen, heparin sulfate and integrins.
Laminin
_______ is the glycoprotein that bridges the lamina lucida and lamina densa to the plasma membrane.
Laminin
What is lamina densa composed of?
type IV collagen and proteoglycans
The basal lamina and the reticular lamina are joined together by type ___ and type ___ collagen fibrils that weave through the loops of type ___ collagen anchoring fibrils.
I; III; VII
______________ connect the basal lamina to the cytoskeletal tonofilaments.
Hemidesmosomes
What are the functions of simple squamous epithelium?
allow rapid diffusion of gases and can secrete fluids (serous fluid)
Where are some examples of where simple squamous epithelium are found?
lining of alveoli of lungs, renal glomeruli, cardiovascular system (heart and blood vessels); membranes covering body cavities and organs
What are the functions of simple cuboidal epithelium?
absorption, secretion, conduction
Where are simple cuboidal epithelium found?
liver, thyroid, lung bronchioles, kidney tubules, mammary glands, salivary glands, and other glands
What kind of epithelium is a single row of cube-shaped cells, often with microvilli?
simple cuboidal epithelium
What kind of epithelium is a single row of tall, narrow cells?
simple columnar epithelium
What kind of epithelium is a single row of flat cells?
simple squamous epithelium
What are the functions of simple columnar epithelium?
absorption, secretion (of mucus)
Where are simple columnar epithelium found?
intestines, uterus, ducts of glands
What kind of epithelium is a single row of a mix of short basal cells and taller goblet cells which creates a stratified appearance all attached to the basement membrane?
pseudostratified epithelium
What are the functions of pseudostratified epithelium?
secretes and propels respiratory mucus
Where are simple columnar epithelium found?
Found in upper respiratory tract including trachea and nasal cavities.
_____ membranes consists of a mucous-producing __________, and underlying layer of vascular connective tissue called ______ _______ and a thin layer of smooth muscle called __________ _______.
Mucous; epithelium; lamina propria, muscularis mucosae
Mucous membranes line passageways that open to the exterior: _________ tract, ___________ tract, _______ tract, and the ____________ tracts.
digestive, respiratory, urinary, and reproductive
