Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

66 Cards in this Set

  • Front
  • Back
What does epithelial tissue develop from?
All three embryonic germ layers
What distinguishes ET from connective tissue?
-CT has very few cells with abundent extracell. matrix
-ET is entirely cellular and the basal lamina is its only CT
3 functions of ET:
1. Surface covering
2. Absorption
3. Secretion
3 characteristics of ET:
-Basal lamina
How are epithelial cells polarized?
Have three sides:
If epithelial cells are avascular how do they get nutrients?
What is the basal lamina?
The basement membrane - the basal layer of Epithelial cells rests on it.
Are epithelial cells single cells?
No; they are a tissue - epithelium
What do all glands consist of?
Epithelial cells
3 ways to organize epithelial tissue:
1. Number of layers
2. Shape of cells
3. Cell membrane specializations
3 categories of ET based on number of layers:
1. Simple
2. Stratified
3. Transitional
What is simple epithelium?
One layer, every cell touches the basal lamina
What is stratified?
Epithelium that consists of more than one layer
What is pseudostratified epithelium?
Simple epithelium that looks like stratified
What is transitional epithelium?
Stratified epithelium that stretches when an organ is full, making it look like there are fewer cell layers than when relaxed.
3 Classes of epithelial cells based on shape:
-Squamous (flat)
-Cuboid (cube)
-Columnar (rhomboid)
If epithelia tissue is stratified, which layer determines the cell shape type?
Most superficial
Which epithelial cell surface is free?
What are the 3 specializations along the lateral border of adjacent epithelial cells?
1. Occluding junctions
2. Anchoring junctions (2 types)
3. Communicating junctions
What does the basal border of an epithelial cell interact with?
The acellular basal lamina
What are apical membrane specializations for?
Interaction with environment
3 Apical memb specializations:
what is the function of each?
1. Cilia - for propulsion
2. Microvilli - for absorption
3. Glycocalyx - for protection and recognition
3 components of a cilia:
-Basal body (centriole) consists of 9 microtubule triplets
-Shaft (axoneme) 9 + 2 doublets
-Flagellum (is a type)
What is the shaft of microvilli made of?
Actin microfilaments
What is the base of a microvilli?
Terminal web consisting of intermediate filaments and actin.
2 places where cilia are commonly found:
-Respiratory tract
What is the ATPase motor on the Microtubules in a ciliary axoneme?
What is the special cilia in sperm called?
Cilia are made of =
where Microvilli are made of =
Cilia = microtubules
Microvilli = actin microfilaments
What are the names of the 4 lateral membrane specializations?
1. Zonula occludens
2. Zonula adherens
3. Macula adherens
4. Gap junction
Which lateral specializations are included in the junctional complex?
Zonula occludens/adherens and Macula adherens
What is the other name for Zonula occludens?
Tight junction
Zonula means
What can pass through the zonula occludens?
Only water and small solutes
What are the tight junction proteins that regulate passage of solute molecules across the zonula occludens? (2)
What makes up the submembrane plaque that tight junction proteins interact with?
ZO proteins
What zone is just beneath the zonula occludens?
Zonula adherens
What is the zonula adherens?
What does it look like?
An anchoring junction
Completely encircles the cell
3 Components that make up the Zonula Adherens:
1. Transmembrane linker protein
2. Subplasmalemmal plaque
3. Cytoskeletal filaments
What are the specific names of the 3 components of the Zonula Adherens anchoring junction?
1. Cadheren
2. Plaque of a-actinin & vinculin
3. Actin microfilaments
What did the actin microfilaments used to be termed?
Terminal web
What is the MAcula ADherens?
A desmosome
What is the Macula Adherens made of? (3 components)
1. Desmoglein (a cadherin)
2. Desmoplakin
3. Keratin intermediate filaments
How is the Macula adherens very different from the other 2 contributors to a junctional complex?
It does not completely encircle the cell.
4th type of lateral cell specialization not included in the junctional complex:
Gap junctions - Connexons
What are Gap junctions?
Communicating junctions that provide electrical and metabolic communication between cells.
What makes up Gap junctions?
2 Connexons each composed of 6 Connexins.
How do Gap junctions differ from other lateral specializations?
There is no plaque or cytoskeletal protein associated with connexons.
What 2 specializations occur in the basal membrane?
1. Hemidesmosomes
2. Adhesion plaques
What is the function of basal specializations?
Attachment to the basal lamina extracellular matrix - ANCHORING.
What are hemidesmosomes?
Half desmosomes
How are hemidesmosomes different from normal desmosomes?
Linker protein = INTEGRIN instead of desmoglein
Attach to Fibronectin in the extracellular matrix instead of an adjacent cell.
Major things to remember about cell-to-cell adhesion:
-Ca dependent
-Cadherins mediate homotypic adhesion
-Tissue-specific via Lectins
What would be heterotypic cell adhesion?
Integrin binding to Fibronectin as in hemidesmosomes.
What finetunes the actions of Cadherins?
How often does skin turn over?
Every 28 days
How often do cells of the small intestine turn over?
Every 5 days
What is metaplasia?
A change in epithelial cells to a biochemically different cell type.
What is Carcinoma?
Malignant tumor of epithelial cells
What is an adenocarcinoma?
A tumor of epithelial glandular cells
How much cancer is due to epithelial cells?
Tumors of epithelium express
Tumors of glia express
Glial fibrillary acidic protein
Muscle tumors express
Connective tissue tumors express
How are tumors diagnosed?
By immunostaining for the IF protein in them.