Groups of cells that are similar in structure and perform a common or related function.
For preparing tissues for microscopic viewing, what 3 steps must be used?
- Fixed (preserved)
- Sectioned (sliced)
Sheets of cells that cover a body surface or lines a body cavity.
Epithelial tissue or Epithelium
Epithelial tissue occurs in the body as....
- Covering and lining epithelium - forms the outer layer of the skin;lines the open cavities of the cardiovascular, digestive and respiratory systems; covers the walls and organs of closed ventral body cavity.
- Glandular epithelium - forms glands
The six functions of epithelial tissues:
- Sensory reception
The five special characteristics of epithelium:
- Specialized contacts
- Supported by connective tissue
- Avascular but innervated
The special characteristic of epithelium meaning that cell regions near the apical surface differ from those near the basal surface in both structure and function.
The special characteristic of epithelium that refers to the connections that keep the cells close together to form continuous sheets.
The special characteristic of epithelium that refers to the type of tissue deep to it.
Supported by connective tissue
The special characteristic of epithelium referring to the fact that it has no direct blood supply, but is supplied with nerve fibers.
Avascular but innervated
The special characteristic of epithelium that refers to its ability to replace itself.
The upper free surface of epithelial tissue.
Lower attached surface of epithelial tissue.
Finger-like extensions on the apical surface of many epithelial tissues that greatly increase the surface area to allow for greater absorption or secretion. Sometimes called a "brush border".
Tiny, hair-like projections of some epithelial tissues that propel substances along the apical surface.
A thin supporting sheet made up of glycoproteins that are secreted by the adjacent basal surface of an epithelium as well as collagen fibers. Makes up half of the basement membrane.
Lateral contacts that bind epithelial cells together into continuous sheets.
Tight junctions and desmosomes
A layer of extracellular material just deep to the basal lamina that contains a fine network of collagen protein fibers that "belongs to" the underlying connective tissue. Makes up half of the basement membrane.
The basal lamina and the reticular lamina form this structure that helps reinforce the epithelial sheet and defines epithelial boundaries.
Epithelium is named by these two factors:
- Shape of cell closest to the apical surface
- Number of cell layers
Slick, friction-reducing epithelium lining in lymphatic vessels and in all hollow organs of the cardiovascular system. Made up of simple squamous epithelium.
Endothelium (mucous membrane)
Epithelium found in the serous membranes lining the ventral body cavity and covering its organs. Made up of simple squamous epithelium.
Mesothelium (serous membrane)
A structure that makes and secretes a particular product.
The aqueous fluid product made and exported from a gland and usually contains proteins but may contain lipids or steroids instead.
A type of gland that eventually loses its ducts and produces hormones that are secreted into extracellular space.
Endocrine glands or ductless glands.
A type of gland that secretes it's products onto the body surface or into body cavities. Includes mucus glands, sweat glands, oil glands, salivary glands, the liver, the pancreas, etc.
A type of exocrine gland made up of only one cell. Examples are mucous cells and goblet cells.
Unicellular exocrine glands
A type of exocrine gland made up of a duct and a secretory unit.
Multicellular exocrine glands
Type of multicellular exocrine gland that has an unbranched duct.
Type of multicellular exocrine gland that has a branched duct.
Type of multicellular exocrine gland that has secretory cells that form tubes.
Type of multicellular exocrine gland that has secretory cells that form small, flasklike sacs.
Alveolar or acinar
Type of multicellular exocrine gland that has both tubular and alveolar shaped secretory units.
Type of multicellular exocrine gland that secrete their products by exocytosis as they are produced, leaving the gland intact.
Type of multicellular exocrine gland that accumulate their products within them until they rupture and are then replaced by the division of underlying cells. Sebaceous glands (oil) are the only true example.
The most abundant and widely distributed type of tissue in the body.
The four main classes of connective tissue.
- Connective tissue proper
- Bone tissue
The four major functions of connective tissue.
- Binding & support
- Transportation of substances
The three common characteristics of connective tissue.
- Common origin - mesenchyme
- Varying degrees of vascularity
- Extracellular matrix
Nonliving portion of connective tissue.
Three main elements that make up connective tissues.
- Ground substance
Unstructured material that fill space between cells within tissues and contains the fibers.
Ground substance is made up of these three components.
- Interstitial fluid
- Cell adhesion proteins (fibronectin, laminin)
Two most important glycosaminoglycans (GAGs) that stick to proteoglycans in ground substance.
- Hyaluronic acid
- Chondroitin sufate
The most widely distributed connective tissue in the body.
Areolar connective tissue
The three loose connective tissues:
The three dense connective tissues, sometimes called fibrous connective tissues:
- Dense Irregular
- Dense Regular
- Dense Elastic
The three varieties of cartilage:
- Hyaline cartilage
- Elastic cartilage
The three types of covering and lining membranes:
- Cutaneous membrane
- Mucous membrane
- Serous membrane
The name given to the layer of connective tissue that underlies mucous membranes (mesothelium).
The three steps of tissue repair:
- Organization to restore blood supply
- Regeneration and fibrosis