Epithelium Flashcards Preview

Histology > Epithelium > Flashcards

Flashcards in Epithelium Deck (30):
1

Common features to all eukaryotic cells

Outer membrane, inner cytosol, cytoskeleton, membrane bound organelles and inclusions

2

What is the cytosol

A solution of proteins, electrolytes and carbohydrates

3

What are the four basic types of tissue

Epithelium, muscle, connective tissue and nervous tissue

4

Function of surface epithelium

Covers and lines surfaces, cavities and tubes

5

Function of specialised epithelial cells

Receptors for special sense organs

6

What are epithelia composed of

Closely aggregated, polyhedral epithelial cells with minimum intercellular space

7

Adhesion between epithelial cells is

Strong

8

Functions of epithlia

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

9

Characteristics of epithelia

- Typically polarised
- Basal surface attached to a basal lamina
- Non-vascular
- Aggregate in sheets where the cells are closely apposed
- Cytoskeleton
- Prominent intracellular junctions

10

What is the cytoskeleton comprised of

Microfilaments, intermediate filaments and microtubules

11

What do intercellular junctions do

Link individual cells together into a functional unit

12

Different intercellular junctions

Occluding junctions, anchoring/adherant junction and communicating junctions

13

How do the filaments of the cytoskeleton work

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

14

Occluding junctions

Form a diffusion barrier

15

Anchoring/adherent junctions

Provide mechanical strength

16

Communicating junctions

Allow for the movement of molecules between cells

17

What is a junctional complex

A close association of several types of unctions found in certain epithelial and other tissues

18

By what are surface epithelia classified

Cell shape, number of layers of cells, cell surface specialisations and presence of any specialised cells

19

Cell shape

Squamous, cuboidal and columnar

20

Number of layer of cells

Simple, stratified and pseudostratified

21

Cell surface specialisations

Microvilli, cilia and keratin

22

Specialised cells

Goblet cells

23

Microvilli

Finger-like projections of the cell membrane. They serve to increase the surface area of the cell membrane

24

Cilia

Motile cell processes. They serve to propel mucous or fluid over the cell surface

25

Keratin

Tough structural proteins. Hair, fingernails and horns are made of keratin

26

Exocrine glands

Product secreted towards apical end of the cell into either a lumen, duct or body surface

27

Endocrine glands

Product secreted towards the basal end of the cell then typically distributed by the vascular system throughout the body

28

Examples of exocrine glands

Lacrimal, salivary, mammary, brunner's, sweat and sebaceuos glands, and the liver and pancreas

29

Examples of endocrine glands

Pituitary, thyroid, thymus and adrenal glands, and the pancreas and ovaries/testes

30

Examples of solid organs made of epithelium

Pancreas, liver, anterior pituitary gland, and salivary gland