Histology of Epithelial Tissue Flashcards
Epithelial tissue is composed of aggregates of _ that are tightly connected by different types of intercellular junctions; these aggregates rest on a supportive structure called the _
Epithelial tissue is composed of aggregates of epithelial cells that are tightly connected by different types of intercellular junctions; these aggregates rest on a supportive structure called the basement membrane
_ is epithelial tissue that lines the blood vessels
Endothelium is epithelial tissue that lines the blood vessels
Aggregates of epithelial cells rest on a supportive structure called the _ ; this separates them from an underlying layer of loose connective tissue that contains blood vessels
Aggregates of epithelial cells rest on a supportive structure called the basement membrane ; this separates them from an underlying layer of loose connective tissue that contains blood vessels
Where do epithelia get their oxygen, nutrients, and signaling molecules from?
Epithelia are avascular, so the blood vessels in the underlying connective tissue are their source of oxygen, nutrients, signaling molecules, and other proteins
* Must pass through connective tissue and across the basement membrane
Epithelial tissue can either be organized into layers that line or cover surfaces (like skin) or into _ that specialize in secreting different products into the body or external environment
Epithelial tissue can either be organized into layers that line or cover surfaces (like skin) or into glands that specialize in secreting different products into the body or external environment
The underlying connective layer in most of our internal organ system is called _
The underlying connective layer in most of our internal organ system is called lamina propria
The underlying connective layer in the skin is called the _
The underlying connective layer in the skin is called the dermis
The (apical/ basolateral) side of the polar epithelial cell faces away from the basement membrane
The apical membrane side of the polar epithelial cell faces away from the basement membrane
The _ is the bottom-most layer or floor of the epithelial tissue
The basement membrane is the bottom-most layer or floor of the epithelial tissue
The basement membrane is composed of the _ and the _
The basement membrane is composed of the basal lamina and the reticular lamina
The basal lamina has two zones: _ and _
The basal lamina has two zones: lamina lucida and lamina densa
The lamina _ has specialized glycoproteins called laminins
The lamina lucida has specialized glycoproteins called laminins
* This layer is right next to the epithelial cells’ plasma membrane
* Laminins bind to hemidesmosomes and also help guide development, maintain structural architecture, aid in wound development and invasion of cancer cells
The lamina _ contains type IV collagen
The lamina densa sits beneath the lamina lucida and contains type IV collagen (plus various glycoproteins and proteoglycans)
The layers of the basement membrane are _ , _ , _ (superficial to deep)
The layers of the basement membrane are:
Lamina lucida (superficial)
Lamina densa (middle)
Reticular lamina (deep)
The reticular lamina is beneath the basal lamina and is derived from connective tissue
_ epithelial cells are a single layer of columnar cells that all rest on the basal lamina but falsely appear to be stratified
Pseuodostratified epithelial cells are a single layer of columnar cells that all rest on the basal lamina but falsely appear to be stratified
There is a special type of stratified epithelium called _ that is seen in tissues that need to stretch, like the bladder, or parts of the urinary tract
There is a special type of stratified epithelium called transitional epithelium that is seen in tissues that need to stretch, like the bladder, or parts of the urinary tract
* Cells in the lowest layer are cuboidal or columnar
* Cells in the upper layer vary in appearance (cuboidal without stretch, squamous when stretched)
Simple columnar epithelium in the rectum (still part of absorptive intestine) are important in transporting water
Anus is part of the outside world so it has tough stratified squamous epithelia
_ are tightly spaced finger-like extensions of cells that are commonly found in the renal tubules and GI tract because they increase the cell’s surface area and aid in absorption and secretion
Microvilli are tightly spaced finger-like extensions of cells that are commonly found in the renal tubules and GI tract because they increase the cell’s surface area and aid in absorption and secretion
* Epithelial cells with microvilli are sometimes said to have a brush boarder
The microvilli contain a core of actin filaments that are cross-linked by a protein called _
The microvilli contain a core of actin filaments that are cross-linked by a protein called villin
_ are thin, highly motile extensions of the apical membranes on some columnar and pseudostratified epithelial cells ; they are commonly found in the respiratory tract and fallopian tube
Cilia are thin, highly motile extensions of the apical membranes on some columnar and pseudostratified epithelial cells ; they are commonly found in the respiratory tract and fallopian tube