Epithelial Tissue

Question 1

epithelial tissue
how do cells look like?
space between cells?
surfaces?

Answer 1

crowded cells
small spaces
upper surface- free
basal - rests on membrane

Question 2

epithelial tissue

blood vessels and nerve cells

Answer 2

blood vessels cannot penetrate but nerves can

so, it is avascular (no blood cells)

Question 3

how does epithelial tissue get its nutrition

it has..

Answer 3

by connective tissue

high power of regeneration/renewal

Question 4

origin of epithelial tissue

Answer 4

all 3 layers
ectodermal
mesodermal
endodermal

Question 5

epithelial tissue is classified into and function of each

Answer 5

surface epithelium - covers
glandular epithelium - for secretion
neuro epithelium - act as receptor
myo epithelium - contractile function

Question 6

surface epithelium types

Answer 6

simple- 1 layer

stratified - 1+ layer

Question 7

simple squamous
formed of + nuclei
functions

Answer 7

formed of 1 layer of flat cells with flat nuclei
function:
provide smooth surface for easy movement
thin membrane for gas exchange

Question 8

sites of simple squamous

Answer 8

1. endothelium (wall of blood vessels)
2. lines of lungs (pneumocytes)
3. lines serous membranes (3P- pleura, pericardium, peritoneum) - mesothelium
   4 lines bowman’s capsule of kidney

Question 9

simple cubical epithelium
formation + nuclei
function
sites

Answer 9

1 layer of cube like cells with central rounded nuclei
function: secretion and reabsorption
sites: small ducts like glands
thyroid follicles
colvoluted tubules of kidney

Question 10

simple columnar epithelium
formation + nuclei
functions
sites

Answer 10

formed of 1 layer of tall columnar cells with basal oval nuclei
functions:
secretion and absorption
sites:
stomach
intestine
pancreatic duct, bile duct, gall bladder
goblet cells

Question 11

simple columnar ciliated epithelium
formation + nuclei
functions
sites

Answer 11

1 layer of tall columnar cells with basal oval nuclei with cilia
functions:
transport fluids or particles in 1 direction
sites:
1. lower part of respiratory tract (lungs)
2. female genital system

Question 12

psedostratified columnar epithelium

types

Answer 12

1 layer but looks like 2 and nuclei on different levels
1. pseudostratified columnar non ciliated
site: male genital system
2. pseudostratified columnar ciliated with motile cilia and goblet cells
site: upper respiratory tract (nose, bronchi, trachea)
3. pseudostratified columnar ciliated with non motile cilia (stereocilia)
not true cilia, long microvilli
site: epididymis

Question 13

function of stratified epithelium

Answer 13

protection

Question 14

stratified squamous epithelium vs transitional epithelium
# of layers
basement membrane

Answer 14

stratified squamous epithelium - 5-30 layers
clear and wavy membrane
transitional epithelium - 6-8 layers in empty bladder
3-4 in full bladder
non clear, non wavy

Question 15

stratified squamous epithelium vs transitional epithelium - basal cell layer

Answer 15

stratified squamous epithelium - columnar cells w/ basal oval nuclei (others originate from this layer)
transitional epithelium - cube cells with central round nuclei

Question 16

stratified squamous epithelium - intermediate layers

Answer 16

polyhedral cells with central rounded nuclei
cells are joined by desmosome
cells become smaller toward surface

Question 17

transitional epithelium - intermediate layer

Answer 17

polyhyderal cells with central rounded nuclei

in full bladder- cells slide past eachother -> decrease epithelium thickness

Question 18

superficial layer - stratified squamous vs transitional

transitional - connected by
covered by

Answer 18

stratified squamous - flat cells with flat nuclei
transitional - dome shaped with central round nuclei and connected by junctional complex
empty bladder- flat cells
covered by rigid plaques

Question 19

stratified squamous sites

Answer 19

keratinized- dead, dry places

non keratinized - wet, living, opening on skin

Question 20

transitional epithelium sites

Answer 20

lines of urinary tract (urothelium)

Question 21

stratified squamous epithelium vs transitional epithelium - function

Answer 21

squamous - protection

transitional - destinsibility and protection against urine

Question 22

layers of stratified

Answer 22

top is variable
middle is always polyhydral
bottom is always columnar shaped

Question 23

stratified cubical epithelium

ex

Answer 23

rare of two layers in ducts of sweat glands

Question 24

stratified columnar epithelium

Answer 24

similar to squamous but superficial cells are columnar
types:
stratified columnar ciliated: in fetal oesophagus
stratified columnar non ciliated : in recto and junction, large ducts or glands, male urethra

Question 25

neuro epithelium acts as consists of sites and functions

Answer 25

acts as receptor and stimuli for sensation consists of sensory and supporting cells sites & functions: taste buds organ of corti - ear for hearing macula utriculi and sacuule - ear for balance crista ampullaris - ear

Question 26

myo epithelium site in between how do they work

Answer 26

modified to contract in between base of secretory cells and basement membrane squeeze secretory cells to discharge into ducts

Question 27

apical specializations

Answer 27

come from above 1. microvilli 2. celia 3. flagella

Question 28

microvilli what type of filaments does it have function

Answer 28

finger like has actin filaments which helps its shape and length function: increase surface area for absorption

Question 29

stereocilia filaments? function?

Answer 29

``` non motile solid cilia not true cilia, long microvilli hair like has actin filaments function: help absorption in male genital system ```

Question 30

cilia | formed of

Answer 30

hair like | formed of microtubules

Question 31

flagella

Answer 31

single long cilia that from tail of sperm for movement

Question 32

glandular epithelium

Answer 32

act as gland for secretion

Question 33

glandular epithelium are classified to

Answer 33

exocrine gland endocrine gland mixed gland

Question 34

glandular epithelium classification - exocrine

Answer 34

formed of 2 portions secretory - forms secretion excretory - carries secretion to outside gland

Question 35

glandular epithelium classification - endocrine

Answer 35

ductless | formed of secretory but no duct system, their secretion is carried to blood

Question 36

glandular epithelium classification - mixed

Answer 36

formed of exocrine part - ducts | endocrine part - no ducts

Question 37

classification of exocrine glands - according to # oc cells

Answer 37

unilocular - one cell , not popular | multilocular - 1+ cells

Question 38

classification of exocrine glands - according to type of secretion

Answer 38

watery secretion serous secretion : watery but contain enzymes mucus secretion mucoserous secretion

Question 39

classification of exocrine glands - according to mode of secretion

Answer 39

1. merocrine ; most common, secretion goes outside cell by exocytosis 2. apocrine ; released out of apex of cell 3. holocrine ; secretion accumulates then cell bursts and the cell is lost with secretion

Question 40

classification of exocrine glands - according to branching of duct

Answer 40

simple - single non branching duct and secretory part | compound - has branching duct like tree

Question 41

classification of exocrine glands - according to shape of secretory part

Answer 41

tubulor - tube alveolar (acinar) - rounded tubuloalveolar - flask shape

Question 42

lateral (side) specializations - cell junctions - tight or occluding junction

Answer 42

Zonula Occludens | 2 cell membranes fuse at certain points to restrict passage of substances between adjacent cells

Question 43

lateral (side) specializations - cell junctions - adherens junction function

Answer 43

zonula adherens two cell membranes seperates by wide intercellular space encircles cell like belt function to provide adhesion between epithelial cells

Question 44

intercellular space and cytoplasm in zonula adherens location connecteted by

Answer 44

intercellular - transmembrane proteins on each side connected by Ca ions cytoplasm - protein bind transmembrane protein to actin filaments (cytoskeleton)

Question 45

macula adherens

Answer 45

desmosomes strongest type of junction that provide firm adhersion among cells mostly in stratified squamous epithelium cells

Question 46

gap junction

Answer 46

nexus two cells separated by narrow cap but connected by channels each channel = 2 connexons = 6 subunits

Question 47

functions of gap junction

Answer 47

permit exchange of ions and impulses

Question 48

hemidesmosomes

Answer 48

basal 1/2 desmosome function: fix epithelium to membrane and connective tissue

Question 49

basement membrane | stain and types

Answer 49

PAS- red Ag- Silver types: basal lamina - epithelial component - has collagen type 4 reticular - ct component - collagen type 3

Question 50

function of basement membrane

Answer 50

supports epithelium and fix it to CT by collagen type 7 | control passage of nutrients and ions

Question 51

basal infoldings

Answer 51

basal surface shows invaginations to increase surface area has mitochondria occurs in ion transporting cells