Epithelium and Glands

Question 1

characteristics of epithelia -classification -where it is found -characteristic -intermediate filament -blood -two general classes

Answer 1

-one of the four basic tissue types -forms continuous sheets lining free surface: external, internal open to environment (GI/bladder/mouth), and internal (pericardium) -polarized: free apical surface but basal surface is attached to basal lamina -expresses keratin intermediate filaments (diagnostic for epithelia) -avascular -two general classes: lining or grandular

Question 2

epithelium functions

Answer 2

-protection -surface transport (cilia in rest epithelium, ovary cilia move the ovum) -absorption (microvili in intestine) -secretion (unicellular and multicellular glands) -trans-epithelial transport (apical to basal and vice versa -reproductive (seminiferous tubules generate sperm) -special sensory (taste buds, hair cells in cochlea) -contraction (myoepithelium)

Question 3

simple epithelium

Answer 3

-single layer of cells attached to the basement membrane

Question 4

stratified -never have…

Answer 4

-multiple layers of cell on top of one another, not all cells have a connection with the basal lamina -NEVER have cilia

Question 5

pseudo-stratified

Answer 5

-cells appear to be on top of one another yet all cells have an attachment with the basal lamina -not all reach the free surface -typically ciliated except in the reproductive system

Question 6

squamous

Answer 6

-flat, elongated cells where the nucleus is generally the tallest part of the cell

Question 7

cuboidal

Answer 7

-eaqually wide as they are tall, appears that the cell membrane is a cube just around the nucleus

Question 8

columnar -often seen with a…

Answer 8

-tall, skinny cells -cell is much taller than the nucleus -can often be seen with a brush border

Question 9

transitional

Answer 9

-also referred to as urothelium, as they are unique to the urinary tract -large surface cells called umberella cells or dome cells, often binucleate

Question 10

keratinizing vs nonkeratinizing

Answer 10

-keratinizing epithelium will have a layer of dead cells on top of the epithelia layer, nonkeratinizing will not

Question 11

glands

Answer 11

-all begin as an epithelial ingrowth

Question 12

exocrine vs endocrine glands

Answer 12

-exocrine: maintain contact with surface epithelium and secrete product into a lumen -endocrine: lose contact with the surface epithelium, secrete into interstitial space

Question 13

unicellular glands

Answer 13

-one cell in the epithelial layer is responsible for secreting a product, is not part of an ingrowth, resides on the surface -goblet cells

Question 14

multicellular, simple glands -example

Answer 14

-unbranched duct -dermal sebaceous glands

Question 15

multicellular, compound glands -example

Answer 15

-branched duct -pancreas

Question 16

merocrine -mecahnism of release -product types -subcategory

Answer 16

-exocrine -releases product via exocytosis -vesicles created inside cell and the vesicular membrane fuses with the plasma membrane upon release and the product is let out into the ECM -zymogens, sweat, mucous, lysozyme -subcategory: eccrine, refers to sweat secretion

Question 17

apocrine

Answer 17

-exocrine -decapitation secretion -when the product leaves the cell, it takes pieces of the cell membrane with it

Question 18

holocrine

Answer 18

-exocrine -the cells fill withprodcut and then the plasma membrane lyses, spilling out the contents -cells at the base of the duct are normal and as they move up, they lyse

Question 19

endocrine gland

Answer 19

-uses exocytosis to release its product into a blood vessel

Question 20

serous

Answer 20

-watery secretion -abundant RER, therefore the cells are very eosinophilic -round nucleus -cells well stained

Question 21

mucous

Answer 21

-thick secretion -clear cytoplasm -flat nucleus -cells poorly stained (glycoprotein does not hold stain well)

Question 22

myoepithelial cell

Answer 22

-also known as a basket cell due to their orientation of being wrapped around ducts -eosinophilic in staining due to the large amount of contractile proteins found in them