Epithelial Tissues Part 1 and 2 Flashcards
What are tissues
Multiple cells that work together to do a common function and are similar in structure
What is the study of tissue?
Histology; subset of Microscopic Anatomy
How many types of tissues are there?
4 Basic types
What are the types of tissue and what do they each do?
Connective (supports/connects tissues together), Epithelial (protects), Muscle (moves), and Nervous tissue (controls)
What does epithelium really mean?
It’s something that creates a boundary between two environments that lets certain things pass
What are the types of epithelial tissue?
Lining Epithelium and Glandular Epithelium
Where is lining epithelium found?
It forms the outer layer of skin and organs
What type of shape does lining epithelium form?
A sheet formation; cells side by side connected to make epithelial tissue
What does glandular epithelium do?
Forms glands of body
Function of glandular epithelium
Produce and release secretory products: sweat, saliva, digestive enzymes
- i.e. thyroid gland
What type of shape does glandular epithelium take on?
Circular substance
What are the main functions of epithelia?
Protection, Absorption, Secretion, Sensory Reception
How does sensory reception work in epithelial cells?
Some epithelial cells have hair which sends signals to the brain to let it know if there is something amiss
What components make up the Epithelial Tissue structure?
Apical + Basal surface and Basal Lamina
What is the Apical surface?
surface that is more exposed to the exterior environment or exposed to the cavity of the organ
What do the apical surface usually have?
Microvilli and Cilia: help with sensory reception or brushing things along (i.e. respiratory tract)
What is the Basal surface?
Located at the bottom; utilized for anchoring the bottom portion to connective tissue
How does the Basal surface anchor itself to other structures/tissues?
With Basal Lamina
How does Basal Lamina work?
acts as an adhesive sheet beneath that Basal surface to join the epithelial with connective tissue (most of the time it’s epithelial)
What does it mean when epithelial tissue is “avascular, but innervated?”
It means that it does not have it’s own blood supply but it get a supplied with plenty of nerves
How does epithelial tissue have high regenerative capacity even though it is avascular?
Although it is avascular, it gets its nutrients and oxygen from nearby blood vessels.
How is epithelial tissue classified?
Arrangement of layers & Cell shape
What are the names of the different types of arrangement of layers for epithelium tissue?
Simple, Pseudostratified, Stratified
What do simple epithelium look like?
One layer; apical and basal surface aligned and in direct contact with the basement membrane
What is simple epithelium tissue’s function?
Helps with passing substances because of thinness and absorption and secretion
What do Pseuodostratified epithelial tissue look like?
Single layered and all cells are in contact with basement membrane
What is the function of pseudostratified epithelial tissue?
Protection and passing substances through; absorption and secretion
What is pseudostratified epithelial tissue common in?
It’s common in the respiratory system
What do stratified epithelial tissue look like?
Multiple layers of cells; not all the cells touch the basement membrane
What is the function of stratified epithelial tissue?
Protection; difficult to penetrate it
What are the names of the cell shapes for epithelial cells?
Squamous, Cuboidal, Columnar
Squamous cells look like?
Flat looking cells
Cuboidal cells look like?
Cube-looking cells
Columnar cells look like?
Long, skinny and tall cells
What’s common for epithelial arrangement layers to have?
It’s common for them to have two different cell shapes
What does more layers mean for epithelial tissue?
More thicker = More protection
What does a single layer of epithelial tissue allow for?
Easy access for substances to pass
What are the only two epithelial tissues that are single layered?
Simple and Pseudostratified
How are cilia helpful?
Found on the apical surface of some epithelial tissue; moves substances or involved in sensation
What is a simple squamous?
A very thin epithelial tissue
Where are simple squamous epithelium found?
Areas where absorption/secretion is important - i.e. walls of blood vessels or walls of air sacs
What does a simple squamous look like if you were to describe it?
Simple arrangement of layers (single layered) & flat looking cells - every cell is in contact with the basement membrane
What is stratified squamous?
A very thick epithelial tissue
Where can you commonly find stratified squamous epithelium?
Areas where protection is important - i.e. SKIN
What’s unique about stratified squamous epithelium
Closer to basement membrane there are cuboidal cell shapes and top there are flattened squamous cells
How many different types of cells can glands be created by?
Consist of one cell or multiple cells
What are the functions of glandular epithelium?
Make or secrete particular substances
What are the two types of gland and how do they differ?
Endocrine (substances are secreted into the bloodstream) & Exocrine (substances are secreted through ducts to their destination)
Which one of the two glands are more controlled
Exocrine - it travels through ducts to get it’s destination; endocrine releases it into the bloodstream so it can practically go anywhere
How do endocrine glands function?
Epithelial cells that produce the hormone surround the storage site. When it’s ready to diffuse, there are blood vessels nearby outside the epithelial to take the hormones into the bloodstream
How do exocrine glands function?
A bunch of epithelial cells form around the duct that collects the substance and when it’s ready to go, the substance goes through the duct and onto the body’s surface
