Tissues + Cell Junctions Flashcards
What are the four primary categories of tissues?
Epithelial
Connective
Nervous
Muscular
How can tissues be studied?
Pathology:
Forensic pathology:
What are the functions associated with epithelial tissue?
Protection: protect deeper tissues from invasion
Secretion: Produces mucus, sweat
Excretion: voids wastes from the tissue
Absorption: absorbs chemicals from the adjacent medium
Filtration:
Sensation:
What are the cellular shapes and arrangements found in epithelial tissue?
simple epithelial tissue squamous epithelial tissue cuboidal epithelial tissue columnar epithelial tissue stratified epithelial tissue pseudostratified columnar epithelial tissue
Where are the functions associated with simple squamous epithelium tissue and where is it located?
allows rapid diffusion or transport of substances through the membrane. it is found in the air sacs of the lungs and inner lining of heart and blood vessels
Where are the functions associated with simple cuboidal epithelium tissue and where is it located?
Absorption and secretion. It is found in the liver and thyroid gland
Where are the functions associated with simple columnar epithelium tissue and where is it located?
Movement of egg and embryo in uterine tube, absorption. Found in inner lining of stomach, intestines.
Where are the functions associated with stratified squamous keratinized epithelium tissue and where is it located?
Resists abrasion and penetration by pathogenic organisms. Found in the epidermis, palms and soles
Where are the functions associated with stratified squamous nonkeratinized epithelium tissue and where is it located?
Resists abrasion and penetration by pathogenic organisms. Found in the tongue and esophagus
Where are the functions associated with pseudostratified epithelium tissue and where is it located?
Secretes and propels mucus. Found in trachea and upper respiratory tract
Tight junctions
At a tight junction, the plasma membranes of two adjacent cells come very close together + are linked by transmembrane cell-adhesion proteins. These proteins seal off the intercellular space + make it difficult or impossible for substances to pass between cells.
Desmosomes
A patch-like intercellular junction that mechanically links two cells together (like the snap on a pair of jeans). Not continuous and cannot prevent substances from passing around them and going between the cells
Gap junctions
Formed by a connexon. Ions, glucose, amino acids, and other small solutes can pass directly from the cytoplasm of one cell into the next through the channel.
