Chapter 4 - Muscle Anatomy
Tissues: Living Communities
Terms in this set (34)
4 primary types of Tissue
1. Epithelial Tissue
2. Connective Tissue
3. Muscle Tissue
4. Nervous Tissue
Tissues cluster to form what?
Organs form what?
Sheets of cells that cover and line other tissues: (ex. Bladder, mouth, blood vessels, all body cavities and ducts
What is the primary function of epithelial tissue?
Protects underlying tissues
Epithelia that manufacture and release secretions
What is the secondary function of epithelial tissue?
Filters biochemical substances
What is a possible third function of epithelial tissue?
May absorb nutrients
(ex. Epithelial that line the gastrointestinal tract absorb nutrient molecules from the gut)
What is a possible forth function of epithelial tissue?
May play a role in the reception of sensory input by detecting changes in the environment and conveying them to the nervous system
What is another function of epithelial tissue?
Epithelia can produce secretions. (ex. Hormones, enzymes)
What is the last function of epithelial tissue?
Epithelia produce excretions (ex. urine, feces, sweat, milk, musk)
Characteristics of Epithelia 1
Polar: Have a sense of direction relative to surrounding structures
Faces the lumen if it lines a tubular organ. Non-tubular organs face the outside.
Faces the underlying connective tissue
Characteristics of Epithelia 2
Epithelial cells have lateral surfaces that are connected to neighboring cells by junctional complexes
_________ cells are avascular
Where do epithelial cells get their nutrients and oxygen?
Rely on underlying connective tissue to provide oxygen and nutrients
Characteristics of Epithelia
Most epithelial cells are innervated although some such as those in the stomach, intestines and cervix lack nerves
formed by the fusion of the outermost layers of the plasma membranes of adjoining cells. Found in tissues in which there can be no leaks. (ex. urinary bladder, digestive tract)
Strong, welded plaque or thickening which connects the plasma membranes of adjacent cells. Bonded with filaments that interlock like velcro (skin, heart, uterus)
intermediate filaments that extend from the plaque into the cytoplasm of each cell like anchors
Half desmosome joins epithelial cells to the underlying basement membrane
Tubular channel proteins (connexons) that extend from the cytoplasm of one cell to the cytoplasm of another and allow for exchange of nutrients and ions (intestinal tract, heart, smooth muscle tissue)
Joins and acts as a barrier for epithelial cells to underlying connective tissue, foundation of epithelial cells, non-living fibers, made by the epithelial cells.
Basement membrane functions
allows for diffusion of nutrients and oxygen from connective tissue to epithelial tissues
extension of the plasma membrane on surface of the cell, they increase surface area, absorption, and secretion (intestinal tract)
in the trachea, moves stuff not the cell
protective, waterproof substance
found on epithelia that line blood vessels to allow the easy passage of blood cells
Classification of Epithelial
1. Number of layers of cells
2. Shape of cells
3. Presence of surface specialization
A single layer of epithelial cells
More than on layer of epithelial cells
False layer. special layer of columnar epithelial cells whose nuclei appear at different heights.