Junctional complex with desmosomes between two epithelial cells of the
ileum (rat)
(for unlabelled original image click here,
please!)
Af = actin filaments (run from
inside the microvilli [Mv] into
the terminal web [Rt] and anchor the microvilli);
Af* = actin filaments which are
attached to the apical cell membrane
of microvilli;
C = cytoplasm (cellular
fluid);
Cjc = Complexus junctarum cellularum (junctional
complex);
Clv = Vesiculum clathrinum
(clathrin-coated vesicle, i.e. endocytotic vesicle);
Cri = crista mitochondrialis
(partly degeneratively widened);
CMV = Corpusculum multivesiculare (multivesicular
body);
D
= Junctio intercellularis digitiformis (interdigitations);
Gx = glycocalyx on top of
the cell membrane; IF = intermediate
filaments;
Lyp
=
Lysosomae (lysosomes);
Lys = heterolysosome;
Ma = Macula adhaerentes (spot
desmosomes);
Mi = mitochondria (crista-type);
Mm = Membrana mitochondrialis (mitochondrial
membrane); Mv = microvilli;
P
= Plasmalemma (cell membrane);
Pr = polyribosomes (the translation
of genetic information takes place here);
Rt = Rete terminale (terminal
web consists of actin-, spectrin- and
further filaments; is anchored to the cell
membrane at Za);
Spi = Spatium intercellulare (intercellular
space);
Za = Zonula adhaerens
(adhaesive stripe = intermediate junction);
Zo = Zonula occludens (tight
junction, very close apposition of cell
membranes due to interlinked membane proteins);
+ = intercellular space with a "glueing substance" in the region of
a spot desmosome [Ma] which consists
of the transmembrane linking proteins desmoglein + desmocollin;
# = cytoplasmic plaque of a Ma (consists of placoglobin and
desmoplakines).
A junctional complex consits of a tight junction (Zonula
occludens), an adhaesive stripe (Zonula
adhaerens) and
a spot desmosome (Macula
adhaerens).
It is responsible for a stable connection between epithelial
cells and allows only a limited amount of water and smallest ions to
pass the intercellular space.
--> ileum; junctional
complex, desmosome, epithelia
--> Electron microscopic atlas Overview
--> Homepage of the workshop
Page, image & copyright H.
Jastrow.
