Histology: Epithelial Tissue Flashcards
The basic dye in staining It binds to acids or bases? Oxidation turns it into
Hematoxylin acids (which are basophilic) hematein
Hematein (oxidized form of hematoxylin) makes structures that it binds to what color? What structures does it stain this color?
Dark blue/purple DNA, RNA, nuclei, ribosomes, GAGs
This is the acidic dye which bonds to bases It makes structures what color? What types of structures does it bind to?
Eosin Pink Proteins, collagen fibers, muscles, cytoplasm
Hematoxylin has a _______ charge
Positive
Eosin has a ______ charge
Negative
This type of tissue consists of polyhedral cells aggregated in sheets. It defines the body surfaces and demarcates outside from inside
Epithelial Tissues
Epithelial cells have much/little ECM (extracellular matrix)
Little
What parts of the body is epithelial tissue found in?
All surfaces of the body
Epithelial tissue is polarized/unpolarized?
Polarized
Does epithelial tissue have a basement membrane?
Yes
What forms within epithelial tissues?
Glands
Epithelium + lamina = ?
mucosa
Epithelial cells comprise more than __% of the cell types in the body
60%
If an organism doesn’t have epithelial cells, it can’t be what type of organism?
multicellular
Most diseases originate in this tissue type of involve a breach in this tissue barrier What process does this often cause? It means epithelial cells lose their polarity and cell-cell adhesion, gaining migratory and invasive properties to become mesenchymal stem cells
Epithelial Tissues Epithelio-mesenchymal transitions
What disease is caused be epithelio-mesenchymal transitions?
Cancer (carcinoma, adenocarcinoma, transitional cell carcinoma, squamous cell carcinoma
In addition to separating outside from inside, what other functions does epithelia serve? (4 additional)
Protection, absorption (peptides nutrients, ions), sensations, movement and transport
This part of the epithelium separates and attaches epithelium to other tissues
Basement membrane
Nerve endings in the skin responsible for sensitivity to vibration and pressure (know the histology)
Pacinian Corpuscle
This type of epithelial cell is structural in nature, not meant for transport because it doesn’t have a lot of cytoplasm
Simple Cuboidal
This type of epithelial cell has lots of cytoplasm and is good for metabolism (excretion/absorption into/from the lumen)
Simple Columnar
This type of epithelial cell is actually attached to the basement membrane even though it sometimes doesn’t appear to be that way Where two places are they commonly found?
Simple Pseudostratified Upper Respiratory Tract and trachea
What type of epithelial cells are in the skin that are good for active transport and diffusion of materials? What do they commonly form the lining of?
Simple Squamos Blood vessels
Look at diagram for pseudostratified epithelium and know goblet cells, basal cells, epithelial cells, basement membrane, lamina propria, terminal bars, mucua, cilia, etc
Note: There is no such thing as truly stratified columnar
This type of epithelium offers protection against mechanical injuries, like in the esophagus
Stratified squamous
This type of epithelium is several layers of cells, surface cells are dome shaped. They change shape when there is a lot of material in the organ Commonly found in two places
Transitional Epithelium bladder, urethra
This occurs as squamous epithelial cells flatten and lose the nucleus. They accumulate this type of fiber to help against abrasion and more importantly protects against…
Keratization Keratin Water loss
Keratinized squamous epithelium is mostly found where…
Epidermis of the skin
This type of apical surface makes a ‘brush border’ to increase surface area, not really motile in nature
Microvilli
This composes the core of microvilli, it is connected to the terminal web and cell membrane
Actin
What is microvilli good for?
Active transport (gut)
This is long microvillia, function not clear. Doesn’t increase SA? Has a ____ core
Stereocilia Actin (just long microvilli)
This apical surface is a motor structure, allowing for active displacement of material inside the lumen. It is longer than microvilli
Cilia
What is the structure of cilia?
9 pairs of microtubules, 2 in microtubules in the middle, like flagella (look at picture
Where is cilia commonly found?
Respiratory tract, trachea, uterine tubes
Where does the microtubule core of cilia connect to?
Basal bodies (look at comparison slide)
These are a mechanoreceptor in epithelial tissues that is responsible for sensitivity to light touch
Meissner’s Corpsucle (Tactile Corpsucle)
Which type of tissue is this?
Where is this type of tissue commonly found?
What is its typical function?
Pseudostratified Columnar Epithelium
Function: secretion, absorption, lubrication
Location: lining of trachea, bronchi, nasal cavity, vas deferins of epididymis
Which type of tissue is this?
Where is this type of tissue commonly found?
What is its typical function?
Simple Columnar Epithelium
Function: absorption and secretion, lubrication
Location: lining of the gastrointestinal system
Which type of tissue is this?
Where is this type of tissue commonly found?
What is its typical function?
SImple Cuboidal Epithelium
- *Function:** absorption and secretion, protection
- *Location:** small ducts of exocrine glands, surface of ovary, kidney tubules, thyroid follicles
Which type of tissue is this?
Where is this type of tissue commonly found?
What is its typical function?
Stratified Squamous
- *Function:** protection, secretion
- *Location:** epidermis (skin), lining of oral cavity, esophagus, vagina
*Note Keratinized cells on top, with no nucleus
Which type of tissue is the arrow pointing to?
Where is this type of tissue commonly found?
What is its typical function?
- *Simple Squamous Epithelial**
- *Function:** exchange of materials (gases & nutrients), barrier, filtration
Location: lining of blood vessels (endothelium), lining of body cavities (mesothelium), lining of respiratory spaces (alveoli) in the lung, Bowman’s capsule in the kidney
Which type of tissue is this?
Where is this type of tissue commonly found?
What is its typical function?
- *Stratified Cuboidal**
- *Function:** secretion, absorption
- *Location:** sweat glands and ducts, larger ducts of exocrine glands
Which type of tissue is this?
Where is this type of tissue commonly found?
What is its typical function?
Stratified Columnar Epithelium
- *Function:** secretion, absorption, protection
- *Location:** largest ducts of exocrine glands
Which type of tissue is this?
Where is this type of tissue commonly found?
What is its typical function?
- *Transitional Epithelium**
- *Function:** ability to distend
- *Location:** urethra, bladder
Name the objects each arrow is pointing at.
1- Tight Junctions
2- Zonula adherens
3- Macula adherens
