Anatomy 9 - Epithelia Flashcards Preview

Second Year - Anatomy CA21007 > Anatomy 9 - Epithelia > Flashcards

Flashcards in Anatomy 9 - Epithelia Deck (38):
1

What is epithelia composed of

Closely aggregated, polyhedral epithelial cells with a minimum of intercellular substance

2

Adhesion between epithelia is

Strong

3

What is epithelia able to cover

Exposed external surface and internal cavities

4

Common features of epithelia

Usually polarised, have a sheet like structure at their basal surface composed of extracellular matrix called the basal lamina, nearly all are non-vascular and they tend to bind together in sheets

5

Surface epithelia

Cover or line surfaces, cavities and tubes

6

What are epithelial tissues derived from

All of the embryological germ layers: ectoderm, endoderm and mesoderm

7

Functions of epithelia

Mechanical barrier, chemical barrier, adsorption, secretion, containment, locomotion by cilia, sensation and contractility

8

Example of mechanical barrier epithelium

Skin

9

Example of chemical barrier epithelia

Lining of the stomach

10

Example of adsorption epithelia

Lining of the intestine

11

Example of secretion epithelia

Salivary gland

12

Example of containment epithelia

Lining of urinary bladder

13

Example of locomotion by cilia epithelia

Oviduct

14

Example of sensation epithelia

Taste buds

15

Example of contractile epithelia

Myoephithelial cells

16

Function of cytoskeleton

To maintain cellular integrity

17

Three main classes of filaments in the cytoskeleton

Microfilamnets, intermediate filaments and microtubules

18

What is the function of the filamentous proteins

They become attached to cell membranes and to each other by anchoring and joining proteins to form a dynamic 3D internal scaffolding in the cell

19

What are microfilaments composed of

The protein actin

20

Functions of microfilaments

Anchorage, movement and extension of the cell membrane

21

Function of intermediate filaments

They bind intercellular elements together and to the plasmalemma

22

What are microtubules made up of

The two tubulin subunits, alpha and beta

23

Functions of microtubules

Move components of the cell

24

What are intercellular junctions

Specialised membrane structures which link individual cells together into a functional unit

25

What are the three types of membrane junctions

Occluding junctions, anchoring junctions and communicating junctions

26

What are occluding junctions

They link cells to form a diffusion barrier

27

What are anchoring junctions

They provide mechanical strength

28

What are communicating junctions

Allow movement of molecules between cells

29

What is linked together in anchoring junction

Submembrane actin bundles

30

If the outer layer of adjacent cells appear fused it is known as

A pentalaminar structure

31

What are desmosomes

They lin k submembrane intermediaries filaments of adjacent cells

32

What do desmosomes provide

Mechanical stability

33

What is found in the cell membranes of communicating junction cells

Several hundred pores

34

What are epithelia classified by

Cell shape, number of layers of cells, cell surface specialisation and the presence of any specialised cell type

35

What are the different cell shapes

Squamous, cuboidal and columnar

36

What are the different number of layers of cells called

Simple - one layer
Stratified - two or more layers
Pseudostratified - tissue appears to have multiple layers, but in fact all cells are in contact with the basal lamina

37

What are the cell surface specialisation categories

Prominent microvilli, cilia and keratinised

38

What specialised cells can be present in epithelia

Goblet cells