Tissues Flashcards
Group of cells of common embryonic origin
Tissues
4 Basic types of tissue
Epithelial
Connective
Muscle
Nervous
Tissues are formed by grouping cells together using a variety of _____________
Intercellular junction
Intracellular junctions that are found where a leakproof seal is needed between cells
Tight junction
Intracellular junction that make an adhesion belt (plaque) that keeps tissues from separating as they stretch and contract
Adherens Junctions
_________ attach to the plaque, partially cross the intercellular space, and connect _______ from an adjacent cells
Cadherin (transmembrane protein)
Intracellular junction that similar to an adherens junction, but the plaque does not attach to microfilaments, rather attaches to intermediate filaments
Desmosomes
“Half-desmosomes”
Transmembrane glycoprotein called integrins replace the cadherins and attach to the basement membrane
Hemidesmosomes
Intracellular junction that has transmembrane proteins called connexins form channels (connexons)
Gap junction
4 Basic tissues
Epithelial
Connective
Muscular
Nervous
Used to line surfaces and form protective barriers
Epithelium
Basal layer of the epithelium secretes _________
Underlying C.T. secretes __________
Basal lamina
Reticular lamina
Functions of epithelial tissue
Protection Filtration Secretion Absorption Excretion
Flat, wide “paving stone” cells
Squamous
Cells as tall as they are wide
Cuboidal
Cells taller than they are wide
Columnar
One layer
Simple
Appears to have layers, all cells attached to basement membrane, but some do not extend to the apical surface
Pseudostratified
Two or more layers. Only basal layer in contact with basement membrane
Stratified
Single layer of flat cells found in air sacs of lungs, blood vessels, or serous membrane
Simple Squamous Epithelium
Single layer of cube shaped cells often found lining the tubules of the kidneys and other glands
Simple Cuboidal Epithelium
Single layer of column-like cells with mucous (goblet cells)
Simple Columnar Epithelium
All cells are attached to the basement membrane in a single layer but some do not extend to the apical surface
Pseudostratified Columnar Epithelium
Distinguishing feature of Keratinized and nonkeratinized
Presence of cell nuclei
Apical surface made up of two or more layers of cube shaped cells that found in the duct of sweat glands and esophageal glands
Stratified Cuboidal Epithelium
Change shape depending on the state of stretch in the tissue that are found in bladder
Transitional Epithelium
Specialized simple squamous epithelium that lines the entire circulatory system from the heart to the smallest capillary
Endothelium
Found in serous membranes such as the pericardium, pleura, and peritoneum
Mesothelium
Single or group of cells that secrete substances into a duct, onto a surface or into the blood
Gland
Glandular epithelium that secrete to surface or lumen, have duct
Exocrine
Glandular epithelium that secrete to extracellular space which is ductless, hormones
Endocrine
The most common manner of secretion of Exocrine gland
Merocrine
Exocrine gland that “bud” their secretions off through the plasma membrane, “decapitation”
Apocrine glands
Exocrine gland that is produced by rupture of the plasma membrane, leasing the entire cellular contents into the lumen and killing the cell
Holocrine secretions
Connective tissue consists of ______
Extracellular matrix
- Ground substance
- Protein fibers
Composed of water and an assortment of large molecules that determine the quality of the tissue
Ground substances