Tissues Flashcards
What are the 4 types of tissue
Epithelia, connective, muscle, nervous
What is epithelia tissue
-tissue that covers surfaces, lines cavities and tubes, forms glands
-consists of loosely packed cells supported by a basement membrane
What are the characteristics of epithelia tissue
Attachment
Avascularity ( doesn’t have its own blood supply )
Polarity apical and basal
Define apical and basal
Apical means away from basement membrane
Basal towards the basement membrane
What does simple and stratified mean
Simple- one layer
Stratified- two or more layers
Define squamous cuboidal and columnar
Flat
Cube
Rectangle
Describe a simple squamous epithelia
-flat cells that have oval shaped nuclei
-one layer cells
-major function is exchange of nutrients and gasses
-location is blood vessels and alveoli
Describe keratinised simple
squamous
-flat surface cells with oval shape nuclei
-many layers
-keratin (tough and waterproof)
-major function-protection and barrier
-location is skin
describe non keratinised simple squamous
-flat surface cells with round nuclei
-many layers
-major function is protection and barrier
-oral cavity and oesophagus
-doesn’t need keratin as its not exposed to the outside world and doesn’t need as much protection
Describe a simple coboidal epithelium
- square cells with round nuclei
-one layer
-major function is secretion and absorption
-glands kidney and tubules
Describe a simple columnar epithelium
-tall cells with oval basalt located nuclei
-one layer
-absorption (nutrients) and secretion (mucus)
-gastrotestinal tract
-has microvilli to increased surface area
Describe pseudostratisfied ciliated columnar epithelium with goblet cells
-tall cells
-appears stratified as some cells dont reach free surface. All cells touch basement membrane
-cillis to move the mucus and goblet cells to act as chamber that produces mucus
-function is mucociliary escalator (cilis and mucus to move bacteria etc)
-trachea and larger respiratory airways
What are the 6 types of epithelia
-simple squamous
-keratinised stratified squamous
-non keratinised stratified squamous
-simple coboidal epithelium
-simple columnar epithelium
-pseduostratified ciliated columnar epithelium goblet cells
What is an intercellular junction
Specialised areas of cell membrane that bind one cell to another
What are the 4 kinds of intercellular junctions
Desmosomes
Hemidesmosomes
Tight junctions
Gap junctions