Histology + Cell Biology (AB_1138): Summary (VU Amsterdam)

Lecture 1 – Epithelia and gland tissue

− 4 basic types of tissue:
1. epithelial tissue
2. connective tissue
3. muscle tissue
4. nervous tissue
− these basic tissue types are functionally organized in organs




Embryonic origin

− cell types that are part of the same basic tissue type can look much different
− these cells share the same embryonic origin

, Epithelial tissue

− an epithelium – a tissue existing of cells that are tightly connected to each other
− it is derived from one of the three primary germ layers (ecto-, endo- or meso-derm)
− 2 types of epithelia:
1. covering epithelia (e.g., skin)
2. glands (invagination of epithelial layers)
− an epithelium is classified based on its embryonic origin, morphology, and cell
organization
− ecto-, endo- or mesodermal
− the shape of the cells
− number of layers (strata)

,− characteristics:
− no blood circulation
− polarized (apical and baso-lateral)
− surface specializations
− presence of a basal membrane


Apical domain

− microvilli – increase surface area
− cilia – movement, sensory function




− many intracellular connections

Tight junction




Adhesion
belt
Terminal
web
Button
desmosome




Hemidesmosome
(a)
Gap junctions

,