epithelial tissue

Question 1

simple epithelium

Answer 1

one cell layer thick where all cells contact basement membrane

Question 2

stratified epithelium

Answer 2

two or more layers where only basal layer is in contact with basement membrane

Question 3

pseudostratified epithelium

Answer 3

appears layered but all cells contact basement membrane and may not reach apical surface

Question 4

squamous cells

Answer 4

flat, wide, irregular in shape & flat nucleus

Question 5

cuboidal cells

Answer 5

as tall as they are wide & spherical nucleus located in center of cell

Question 6

columnar cells

Answer 6

slender & taller than they are wide & oval nucleus that’s oriented lengthwise in basal region

Question 7

transitional cells

Answer 7

change shape depending on stretch of epithelium

Question 8

simple squamous epithelium

Answer 8

single layer of flat cells w/ spherical/oval nucleus
-function: thinnest barrier that allows rapid diffusion & filtration; secretion in serous membranes
-location: lines air sacs of lungs (alveoli), blood & lymph vessel walls (endothelium), & serous membranes of body cavities (mesothelium)

Question 9

simple cuboidal epithelium

Answer 9

single layer of uniform cells that are as tall as they are wide w/ centrally located spherical nucleus
-function: absorption & secretion
-location: lining of kidney tubules, thyroid gland follicles, surface of ovaries, secretory regions & ducts of most exocrine glands

Question 10

nonciliated simple columnar epithelium

Answer 10

single layer of nonciliated cells that are taller than they are wide w/ oval nuclei oriented lengthwise in basal region
-apical surface contains microvilli/brush border
-contains unicellular glands called goblet cells that secrete glycoprotein mucin that forms mucus when mixed w/ water
-function: absorption & secretion
-location: lines digestive tract from stomach to anal canal

Question 11

ciliated simple columnar epithelium

Answer 11

single layer of ciliated cells that are taller than they are wide w/ oval nuclei oriented lengthwise in basal region
-cilia projecting from apical surface moves mucus along
-goblet cells interspersed
-function: secretion of mucin & mucus movement; oocyte movement through uterine tube
-location: lines bronchioles in lung & uterine tubes

Question 12

ciliated pseudostratified columnar epithelium

Answer 12

single layer of cells of varying heights where all cells connect to basement membrane but not all reach apical surface
-cilia on apical surface & goblet cells
-function: protection, secretion of mucin, movement of mucus along epithelial surface by cilia
-location: large passageways of respiratory system (nasal cavity, pharynx, larynx, trachea, bronchi)

Question 13

nonciliated pseudostratified columnar epithelium

Answer 13

single layer of cells of varying heights where all cells connect to basement membrane but not all reach apical surface
-lack cilia & goblet cells
-function: protection
-location: rare- mainly in male urethra & epididymis

Question 14

keratinized stratified squamous epithelium

Answer 14

multiple cell layers where basal cells are cuboidal & alive & apical cells are squamous & dead but filled with keratin
-cells lack organelles & nuclei
-function: protection of underlying tissue from abrasion
-location: epidermis of skin

Question 15

nonkeratinized stratified squamous epithelium

Answer 15

multiple cell layers where basal cells are cuboidal & alive & apical cells are squamous & alive
-kept moist w/ secretions (saliva, mucus)
-cells have organelles & nuclei but lack keratin
-function: protection of underlying tissue from abrasion
-location: lines oral cavity, pharynx, esophagus, vagina, anus

Question 16

stratified cuboidal epithelium

Answer 16

two or more layers of cells where apical cells are cuboidal & as tall as they are wide
-function: protection & secretion
-location: sweat glands, male urethra, periphery of ovarian follicles

Question 17

stratified columnar epithelium

Answer 17

rare two or more layers of cells where apical cells are columnar
-function: protection & secretion
-location: large ducts of salivary glands, conjunctiva or eye, male urethra

Question 18

transitional epithelium

Answer 18

appearance varies where in relaxed state, basal cells are cuboidal & apical cells are large & rounded but in stretched state, apical cells are flattened
-some cells are binucleated
-function: allows for stretching as bladder fills
-location: urinary tract (bladder, ureters, & urethra)