Building tissues from cells Flashcards
1
Q
What are tissues?
A
collections of similar cells and the material surrounding them
2
Q
What is tissue classification based on?
A
- structure of cells,
- the composition of the extracellular matrix,
- the functions of the cells in a particular tissue.
3
Q
What are 4 major types of adult tissues?
A
- Epithelial
- Connective
- Muscle
- Nervous
4
Q
What is structure of epithelia?
A
- sheets of cells
– v. close together, - flat/folded
5
Q
What is main function of epithelia?
A
- they cover the body surface (epidermis)
- they line almost all internal cavities
6
Q
How do epithelia receive nutrients, oxygen and metabolites?
A
- depend upon diffusion
- blood vessels never pass through the basement membrane/sheets of epi cells
– but blood vessels in connective tissue underneath basement mem – diffusion occurs
7
Q
How is epithelia organised e.g in gut wall?
A
- lumen
- epithelial cells
- basement membrane
- CT
- smooth muscle
- CT
- epi cells
8
Q
What is the importance of the basement membrane?
A
- phys barrier between epi cells + connective tissue cells + cells of blood supply
- provide support and attachment between them
- all cells except immune cells stay on 1 side/other of basement mem
9
Q
What are 4 ways epi tissue classified?
A
- cell shape
- layer structure
- surface specialisation
- location & function
10
Q
What are the 3 shapes of epi tissue?
A
- squamous
- cuboidal
- columnar
11
Q
What is structure of squamous epi?
A
- flattened
- layer parallel to mem,
- v.thin
12
Q
What is structure of columnar epi?
A
- sideways flattened sheet.
- Cells tall + thin
13
Q
What are 3 layer structures of epi?
A
- simple
- pseudostratified
- stratified
14
Q
What is structure of simple epi?
A
- 1 layer of epi sheets
15
Q
What is structure of pseudostratified epi?
A
- 2-3 layers of cells
– every cell attached to BM (so should really be simple but looks stratified hence pseudostratified) - Tall + thin columnar cells.
