List of abbreviations
of micros-
specialist terms
explained in
English +

Every attempt was made to provide correct information and labelling, however any liability for eventual errors or incompleteness is rejected!

dieser Seite

Dr. med.
H. Jastrow

of use
Overview Plasma cells (Plasmocyti):
Pages with explanations (still in German) are linked to the text below the images when available
plasma cell 1 from the pharyngeal tonsil
(Tonsilla pharyngea, human)
plasma cell 2
Tonsilla pharyngea (human)
Detail 1:
Detail 2:
Detail 3:
Detail 4:
mitochondria (crista-type)
plasma cell 3
Tonsilla pharyngea (human)
plasma cell  4
T. pharyngea (human)
detail: nucleus, RER,
plasma cell  5 from 
T. pharyngea (human)
detail 1:
detail 2:
mitochondrium (crista-type)
Detail 3: rough
endoplasmic Reticulum (RER)
plasma cell  6 from 
T. pharyngea (human)
detail 1:
detail 2:
dilated RER plasma cell 
T. pharyngea (human)
detail: primary lysosome,
rough endoplasmic reticulum
other plasma cell of the lamina
propria mucosae of the colon (rat)
plasma cell
salivary gland (rat)
detail: centriol,
plasma cell
plasma cells of the Lamina propria
mucosae of the colon (Rat)
4 plasma cells near to a
non-myelinated nerve
detail thereof:
single plasma cell
plasma cells close
to a venole (monkey)
perivascular free connective tissue
cells + a plasma cell (monkey)
plasma cells of the Lamina propria
mucosae of the colon (rat)
the next details are
from this plasma cell (rat)
detail: nucleus showing
"spokes of a wheel" structure
detail: Mitochondrium
of the crista-type
 nuclear pore
Plasma cells (also called Plasmocytes; Plasmacytes; Terminologia histologica: Plasmocyti) are free cells of connective tissue able to move slowly through the latter. Plasma cells are mature and active B-lymphocytes synthetising immunglobulins (Ig). Their prominent rough endoplasmic reticulum (RER) nearly only produces these Ig. Typically it is considerably widened on several locations. A plasma cell always only releases a single Ig, i.e. monoklonal antibody, specific for only one epitope of an antigen. It is most probable that Ig are leaving the RER, diffuse throug the cytoplasm to be carrierd out of the cell by transmembrane carrier proteins in the cell membrane since vesicles typical for exocytosis or storage of secretion products are practically never observable. Further exocytosis is not detectable and the Golgi-apparatuses seem too small compared to RER for a fast enough modification of Ig. The nucleus shows a typical "spokes of a wheel" structure when centrally cut with nucleolus associated heterochromatin in the centre surrounded by a ring of low electron dense euchromatin. Further nuclear membrane associated heterochromatin shows wide spaces for a quick penetration of mRNA through the nuclear pores resulting in low electron dense "spokes of a wheel". Plasma cells degenerate when not stimulated for several days/weeks. In general plasma cells are located close to blood vessels. Some of the synthetised Igs of type E (IgE) stimulate mast cells and thus support inflammation others directly serve for attack of antigens (humoral defense).
Depending on the size and arrangements of subunits 5 classes of antibodies were defined:
IgA relative molecular mass: 162 kDa per monomer; 2 subclasses IgA 1 and 2; secreted by plasma cells in connective tissue layers located beyond epithelia thus IgA mainly is present in the mucus
IgD relative molecular mass: 172 kDa; 2 heavy delta-chains and 2 light kappa or lambda-chains  IgD is important for differentiation of memory and plasma cells.
IgE relative molecular mass: 196 kDa; 2 heavy eta-chains and 2 light kappa or lambda chains. IgE causes allergic reations.
IgG: relative molecular mass: 150 kDa, ,IgG passes the blood-placenta barrier and thus gets into the blood of the embryo / fetus to protect it before and after birth (inborn immunity).
IgM relative molecular mass: 900 - 935 kDa in most cases is a very large pentamer consisting of 5, but in some cases also may be a hexamer consisting of 6 Y-shaped monomers. The latter are interconnected by a binding protein (J-chain of 15 kDa).

An English page with much more detailed information and images is only available in the professional version of this atlas.

--> blood cells, lymphocytes, rough endoplasmic reticulum, bone marrow, connective tissue, mast cells, macrophages, heterochromatin
--> Electron microscopic atlas Overview
--> Homepage of the workshop

Three pictures were kindly provided by Prof. H. Wartenberg; other images, page & copyright H. Jastrow.