Epithelial Flashcards
List the cell morphology possible for epithelium.
Squamous- flat (shield-like)
Cuboidal- same height as width (box-like)
Columnar- taller than they are wide.
Transitional- cells will vary with distension of the urinary organ which they line. stretching is minimal, cells appear full. When the organ is distended, the epithelium becomes flattened.
endothelium vs. mesothelium
Simple Squamous Cells
- endothelium-lining blood vessels and lymphatic vessels
- mesothelium-lining body cavities
transitional epithelium
Special shaped epithelial
- lining of urinary tract
- superficial cuboidal cells bulge into lumen
- cells flatten when organ is distended (stretched)
- Superficial cells have a specialized plasma membrane providing an osmotic barrier between urine and tissue fluids
simple squamous epithelium
Composed of flat elongated cells with round/oval nuclei
Common locations:
- lining body cavities (Mesothelium)
- alveolar walls
- luminal surfaces of blood vessels (endothelium)
State three characteristics of surface or lining epithelium.
Surface epithelium= continuous sheet of one or more cell layers.
- selective diffusion
- AVASCULAR
- usually simple
Explain the term ‘pseudostratified’
pseudostratified epithelial cells may appear stratified, but all cells make contact with the basal lamina.
Explain keratinization (cornification). Suggest sites in the body where this might occur and why.
happens to Stratified Squamous Epithelium!
SSE is usually in areas where there is lots of movement/frequent contact.
- Nonkeratinized- thick outer layer of nucleated cells
- Examples: Cornea, Esophagus, Oral cavity, Vagina
- Keratinized- Cells on the surface no nuclei and are composed mainly of keratin. keratin is water-resistant protein.
- Examples: Epidermis, Proventricles, Oral cavity, Vagina in estrus
Be able to distinguish a unicellular gland from a multicellular gland in section and give locations of each.
Unicellular Glands- Found in epithelial lining and glands of intestine and in respiratory tract.
- ex. goblet cells
Multicellular Glands- multiple cells in gland. Can be exocrine or endocrine
adenomere
Adenomere- cells of the exocrine secretory end-piece that manufactures the product before passing it on to other cells that express it in the duct system.
**classification of glands based on shape of adenomere
acinus
acinar= shape of a compound secretory gland with pi shaped end piece
ex. pancreas and salivary gland
tubulus
tubular= shape of compound secretory gland with strait or coiled end piece
ex. sweat gland, stomach glands, colon glands
serous
SEROUS: gland producing watery product, contains enzymes.
traits- cells with round nuclei, the cytoplasm is basophilic in the basal portion and acidophilic in the apical part (zymogen granules)
Example: sweat
mucous
•MUCOUS: gland producing slick, viscous secretion
Traits- Cells with flat heterochromatic nuclei at the base of each cell • Cytoplasm is vacuolated (frothy) and pale • Mucinogen granules are not detectable with routine stains
mixed acinus
•MIXED: a gland producing both mucus and serous secretion.
Traits- Mucous and serous cells sharing a common duct system, mucous acinar units with associated crescent of serous cells, a “serous demilune”
Example: saliva
sebum
•SEBACEOUS: glad producing oily secretion (often known as sebum)
traits- Centrally located nuclei • Cytoplasm is pale and ‘foamy’ as lipid droplets are washed out during processing
ex. eye lid or hair folicle
Classify glands based on secretory product.
- SEROUS: watery product, contains enzymes.
- Example: sweat
- MUCOUS: slick, viscous secretion
- MIXED: a gland producing both mucus and serous secretion.
- Example: saliva
- SEBACEOUS: oily secretion, often known as sebum
Explain simple vs. compound glands
Both are types of multicellular glands
- simple glands-one opening draining gland
- compound glands- duct branches many times
Identify
simple squamous epithelium
Identify
simple cuboidal epithelium
* Lining of tubule in kidney
Identify
simple columnar epithelium
** Lining the gall bladder
Identify
pseudostratified epithelium
** Trachea
Identify
- stratified squamous epithelium- non-keratinized
** Cornea
Identify
transitional epithelia
Identify
sebaceous, mucous, serous glands.
Identify
Stratified squamous epithelium- Keratinized
Make a flow chart illustrating the classification of epithelial cells.
Define merocrine, apocrine, holocrine, and endocrine
** apocrine is the only gland you can see morphologically (only one that can be on the test!)
Epithelial cells are always _______.
Epithelial cells are always reparing!
