Epithelial Tissue Flashcards
What is the common characteristic that categorizes tissues as “epithelial?”
Morphology
What is a tissue:
- Aggregate of cells that are characterized by large amounts of intercellular materials?
- Aggreate of cells taht are characterized by small amounts of intercellular material?
- Collection of cells and cell product having one or more common function
3 - Collection of cells and cell product having one or more common function
The [] line both the xternal and intrnal surfaces, of the body, developmentally and it invades the connective tissue to form the functional tissue of glands
Epithelium
Epithelium is highly:
- Vascular
- Cellular
- anaerobic
- Partitioned
Cellular
These are the most important epithelial functions:
- Protection
- Secretion
- Absorption
- Transport
What type of “lower” membrane are all epithelia associated with?
Basement Membrane
What are three examples of epithelial surface modifications?
Cilia
Stereocilia
Microvilli
How does blood nourish the epithelia?
- FALSE - it doesnt
- Epithelial is avascular
- It receives its nourishment by diffusion from the connective tissue.
Epithelial Cells must very diverse and resilient because they face many harsh climates on the body including:
- Skin - ?
- Lining Body Cavities - ?
- Secretory and Excretory - ?
- Lining Distensitble Organs - ?
- Skin - have to protect against dissecation, mechanical abrasion, bacterial infection, and radiation
- Lining Body Cavities - has to stay moist, absorb and secrete stt
- Secretory and Excretory - forms glandular tissue
- Lining Distensitble Organs - has to be able to change shape to accomdate the swelling and shrinking of things like the bladder
What are the common characteristics of Epithelia?
- Highly Cellular
- Tightly Adherent
- Avascular
- High regenerative capacity
- highly polarized
- presence of basement membrane
- nuclei mirror cell shape
- derived from all 3 germ layers
Which of the following is not a function of epithelia?
- Protection
- Transportation
- Secretion
- Action Potentials
- Lubrication
Action Potentials!
Which of the following is not a function of Epithelia?
- Absorption
- Sensory Reception
- Reproduction
- Initiating Apoptosis
Initiating Apoptosis
What is the difference between excretion and secretion?
- Excretion is getting rid of waste type products
- Secretion is an intentional release of a substance
Why is it important for epithelia to regenerate so rapidly?
These cells occupy some harsh environments - ex: skin, lining of the GI tract, lining of esophagus…they get degraded quickly. So, they need to be able to reproduce/regenerate
What are the 3 shapes and epithelial tissue can take?
Squamos
Cuboidal
Columnar
How are epithelial cells named regarding their “layers?”
- Simple - 1 layer
- Pseudostratified - all cells are attach to a basement membrane, and not all can reach the free surface
- Stratified - 2 or more layers
- Transitional - distensible type cells that can change shape.
Simple squamos cells:
- Normally play a passive role allowing for the exchange of [] and [] across their membrane
- 2 distinction
- [] lines all blood/lymphatic vessels and the heart in the body
- [] lines the body cavities
- gas and nutrients
- 2 distinctions
- Endothelial
- Mesothelial
Simple Cuboidal Cells:
- Frequently engaged in [] transport or synthesis of [] products
- With increased cytoplasmic volume (compared to squamos cells) they have more [], [] (organelles)
- active; secretory
- Mitochondria, ER
Simple Columnar Cells:
- Frequently have either [], [], or [] function
- Nuclei tend to line up in a [] fashion
- Occur on surfaces of [] curvature than cuboidal cells
- [] or [] cells occur in columnar cells…these are unicellular glands
- protective, absorptive, secretory
- Polarized
- Less
- Mucous or goblet cells
T/F
Pseudostratified Epithelia still consists of cells that reach from the basement membrane to the free surface of the cell?
False
Not all cells reach the free surface in pseudostratified Epithelia
Where are the main places you could find pseudostratified columnar epithelia?
- Respiratory Tract (with cilia AND Goblet cells
- Male Reproductive System
- Epididymus (with stereocilia)
- Efferent Ductules (with Cilia)
- Ductus deferens (with cilia)
What type of pseudostratified columnar cells can be found in these locations?
- Respiratory Tract
- Epididymis
- Efferent Ductules
- Ductus Deferens
- ciliated pseudostratified columnar epithelium with goblet cells
- pseudostratified columnar epithelium with stereocilia
- Ciliated pseudostratified columnar epithelium
- Ciliated
What is the function of stratified squamos cells?
Protection from abrasion, desiccation
What type of cell layer is a cornified epithelial??
Keratinized dead cell layer
What characterization of cells would you find on large ducts of various glands like sweat glands, pancreas, and the parotid glands?
Stratified Cuboidal
Where you would find stratified columnar cells?
They are rare, but you’d find them in large ducts and in transition zones in the pancreas and parotid gland
Ex: Rectal-anal junction
- Transitional cells are almost exculsively found in these 3 places?
- Function Example: if the bladder is full…what would these cells look like?
- Can these cells be bi-nucleated?
- Bladder, Ureter, Renal Pelvis
- They would be flattened. If the bladder was empty, these would be scalloped
- Yes!
What apical modifications are made to epethial for, protection, absorption, locomotion?
- Protection
- Cornified
- Absorption
- Microvilli
- stereocilia
- Locomotion
- Flagella
- Cilia
The glycocalyx helps being what process for epithelia cells?
Absoprtion
Microvilli
- Have a [] core
- Are involved in the process of []
- In the intestines it is called [] and in the kidneys it is called []
- They are attached to [] [] within the cell to give structural strength
- actin core
- absoprtion
- striated border; Brush Border
- Intermediate Filaments