Epithelia Flashcards
what is the amorphus component of the ECM?
the ground substance
what is the most basic way to define the purpose of studying histology?
the relationship between tissues and their respective cells with the physiological features of the tissue/organ
what relationship allows histology to come alive?
the relationship between organisation of different tissues with their specialised cells and ECM in the context of the organ they form
what are the four types of tissue
- epithelia
- muscular
- nervous
- connective
what type of tissue are glands?
epithelial tissue
what is a common function of all epithelial tissues
barrier
what are the functions of epithelia?
- physical protection e.g skin
- control permeability (absorption, secretion, excretion)
- provide sensation
- provide specialised secretions
true or false, epithelia are polarised
true
due to different specialisations of apical and basal layers
where is simple epithelia usually found?
where secretion, filtration or absorption is needed
where is stratified epithelia usually found?
where protection is required
mesothelium and endothelium are a type of __________ ________ epithelium, and are derived from the __________ and _________ respectively
simple squamous, mesoderm, endoderm
describe appearance of simple squamous epithelia
- central nuclei
- cobblestone appearance
- fenestrations allowing passage of large molecules
what are the main functions of simple squamous?
- reduce friction
- filtration
- absorption and secretion
describe simple cuboidal epithelia
- cube shape
- Large surface area (good for secretion and absorption)
- central nuclei
where is simple cuboidal epithelia found?
- glands, ducts
- tubules of kidney
describe simple columnar epithelia
- tall column cells
- elongated nuclei that are found lower in the cell
- nuclei are closer together than with cuboidal
- microvilli found sometimes (increases surface area for more absorption)
where are simple columnar epithelia found
collecting duct of kidney
- microvilli for large surface area because we want heaps of absorption
describe pseudostratified columnar epithelia
- still only one layer of cells
- every cell attaches to the BM
- cilia (movement)
where is pseudostratified columnar epithelia found?
- lining of nasal cavity
- bronchi
what are the two functions of pseudostratified columnar?
protection (to a degree) and secretion
