FunMed epithelia and glands Flashcards
where do you find simple squamous cells?
outer surface of organs and blood vessels
where do you find the mesothelium?
lining of the pleua
what sort of epithelium is the mesothelium
simple squamous
what is the advantage of the shape of simple squamous cells?
ideal for diffusion of gases
what sort of cells line the endothelium?
simple squamous
where do you find simple cuboidal epithelia
glands and ducts
name 4 ducts lined with simple cuboidal epithelial cells
salivary
where is the nucleus normally found in simple cuboidal cells?
near the basement membrane
where do you find simple cuboidal cells
areas of active absorption of material eg stomach
what do simple columnar cell often have on the apical surface?
microvilli
what do microvilli look like in LM pictures
brush border
what holds up microvilli?
actin filaments
what are pseudostratified cells?
squished in but not stratified
where so you find cilia?
respiratory tract
what are cillia made of?
microtubule and DYNEIN protein
what do cilia do?
waft mucus
where would you find non-keratinising stratified squamous cells?
places which are abrased but also lubricated eg oesophagus
where do you find keratinised stratified squamous cell
skin
what are microtubules made of
tubulin protein
what is metaplasia
one type of tissue (say stratified cuboidal) is replaced by another (say stratified squamous)
what is neoplasia
literally new growth. Often dodgy. Cells grow autonomously without need for growth signals. Can metastasise
what are transitional epithelial cells
ONLY FOUND IN THE URINARY SYSTEM<br></br>when bladder is empty
where do you find stratified cuboidal cells
Big glands - mammary
what are the specialised functions of stratified cuboidal cells?
layer of cells keeping lumen and underlying tissue separate<br></br>specialised for selective absorptions and secretions<br></br>many junctions keeping the fluid IN THE LUMEN
are stereocilia motile
No
what are stereocilia made of
actin filaments
what is a tight junction
<ul><li>nearest to apical surface</li><li>occluding junction</li><li>determines which ions & molecules diffuse between cells</li></ul>
<br></br>
what is an adhering junction?
below the tight junction
what is a Desmosome?
hold adjacent cells togetehr but also have a network of intracellular fibres between desmosomes
what is a gap junction
a bit like a plughole. Allows for small molecules and ions to pass directly between cells.
what does a gap junction look like on EM
like the two outer leaflets of adjacent cells have fused
what stain can you use to show the basement membrane?
periodic acid schiff
what is the basement membrane made of?
collagenous and non-collagenous glycoproteins and proteoglycans
how do epithelial cells and basement mambrane interact integrins on basal surface of cells
interacts w proteins in the BM
what do glands do
secrete stuff
can glands be unicellular
yes
what is exocrine secretion
product is secreted onto a surface or into a duct
what is endocrine secretion
product is secreted directly into intercellular space
what is merocrine secretion
type of exocrine - vesicles fuse with apical cell membrane to secrete the product
what is apocrine secretion
top of cell containing vesicles is pinched off to release the product
what is holocrine secretion
entire cell dies to secrete the product - eg sebum from sebaceous gland
what is an acinar duct
sac like secretory portion then duct
where would you find a coiled tubular duct
sweat glands
where would you find a branched tubular duct
glands in uterus and stomach
what would you see on a LM of squamous cell carcinoma
a lot of keratin in swirls
what is adenoma?
benign tumour of epithelial tissue with glandular origin or characteristics
what are the characteristics of adenoma?
Cell dysplasia (atypical or loss of normal differentiation of epithelium) <div>•Irregular cells with hyperchromatic nuclei</div> <div>•Stratified or pseudo-stratified nuclei</div>
what is an adenocarcinoma
cancer that starts in glandular tissue that makes muus or fluids
describe characteristics of adenocarcinoma
neoplasia of epithelial tissue that has glandular origin or characteristic
where tdo most breast cancers start
ducts and lobules
where do colon cancers originate
mucus secreting goblet cells and water absorbing cells
40% of lung cancers are….?
adenocarcinomas
where do lung adenocarcinomas originate
peripheral lung tissue
