A&P: 4.1 (flashcards I made)

epithelial tissue characteristics

if a cell comes into contact with air or fluid it is epithelial

it is a boundary or protect or exchange of passway

all locked together

covers most of the bodies surfaces

layers of epithelial tissue

free surface (apical) - in contact with air or water

lateral surface - connected to adjacent layer

basil surface - underlying structures/basement

is epithelial tissue vascularized?

no

basement membrane

specialized extracellular matrix

characteristics of basement membrane

porous

only way nutrition can get through to the epithelial tissue (diffusion)

richly innervated

functions of epithelial tissue

protecting underlying structures

acting as barrier

permitting the passage of substances

secreting substances

absorbing substances

simple

single layer

stratified

mutliple layers

psuedostratified

looks stratified

actually is one layer

(all epithelial cells are in contact w/ basement membrane but all nuclei is scattered throughout)

transitional

specialized type of epithelium

cell changes shape based on circumstances

squamous

flat, scale like

cuboidal

about equal in height and width

columnar

taller than wide

simple squamous epithelium

1 layer

looks like bubble wrap (bumps are nuclei of cells)

function: diffusion, filtration (some secretion/protection)

found in:

• kidneys (filter blood)

• heart (need lot of oxygen to keep pumping

• lungs (lining of alveoli -rapid diffusion of oxygen+CO2)

• lining in serous membrane

simple cuboidal epithelium

• some have microvilli

• function: filtration, absorption, move stuff, secretion (particles in mucous)

• found in

  • kidneys (nephron/tubules)

  • terminal bronchioles (have cillia to move stuff like the mucous in lungs)

  • choroid plexuses of the brain (fluid passes thru the brain)

  • surfaces of the ovaries

simple columnar epithelium

function: moves particles, absorption, protection, secretion

found in

• uterus (moves eggs from ovary to the fallopian tube into uterus)

• stomach ( absorption)

• intestines (absorptions)

• lungs (moves particles through lungs)

pseudostratified columnar epithelium

• almost always ciliated (hairy)

• almost always have goblet cells (create mucous)

• move mucous w/ hairs

• found in

  • tubes of ears

  • trachea

  • bronchi

stratified squamous epithelium

several layers of cells

progressive flatten out

• non keratinized

  • moist

  • retain nucleus and cytoplasm

• ex:

  • skin

  • mouth

  • esophagus

• function

  • things don’t diffuse really well

  • good barrier

    • protect against abrasions, cuts, etc

    • prevents infections

    • prevents from losing our fluids

stratified cuboidal epithelium

function

• secretion

• absorbs

• protection

ex

• cells of ovary

transitional epithelium

• stratified in multiple layers

• when organ is not full the cells are cuboidal but when organ is full it becomes squamous

• found ONLY in urinary bladder

free surface modifications of epithelium

smooth

• reduce friction

• called endothelium

folds

• in transitional epithelium where organ must be able to change shape

  • urinary bladder

• microvilli

  • increase surface area for absorption or secretion

desmosomes (cell conection)

• Found in areas subject to mechanical stress

• Keep cells stuck together

hemidesmosome (cell conection)

attaches epithelium cells to basement membrane

tight junctions

holds cells together and forms a permeability barrier

adhesion belt

anchor cells together

gap junctions

have little channels

allow cells to communicate w/ each other

endocrine

no open contact with exterior; no ducts; have an extensive network of blood vessels; produce hormones.

exocrine

open contact maintained with exterior by the ducts that open onto the free surface of the epithelium

stratified columnar epithelium

function: secretion, protection

location: mammary glands, larynx

merocrine gland

a type of exocrine gland that release their chemical substances via exocytosis without damaging or losing any part of the secreting cells

apocrine glands

a type of exocrine sweat gland that produces a thick, oily fluid which causes body odor when broken down by skin bacteria

holocrine glands

a type of exocrine gland where the entire mature cell ruptures and dies to release its stored secretory products and cellular debris