Cytoplasm Dr.Jastrow's electron microscopic atlas

Vocabulary
of micros-
copic
anatomy
specialist terms
explained in
English +
German

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

dieser Seite

Editor:
Dr. med.
H. Jastrow

Conditions
of use

Overview cytoplasm (Cytoplasma):
Pages with explanations are linked to the text below the images if available! (Labelling is in German)


nucleus and cytoplasm of a hyaline cartilage cell (rat)	cytoplasm of cells in the Ductus epididymidis (rat)	cytoplasm of epithelial cells epididymal duct (rat)	cytoplasm + Nissl bodies ganglion cell (guinea pig)	exocrine and endocrine cells of monkey pancreas	cytoplasm rich in actin filaments smooth muscle cell (monkey)	cytoplasm of an exocrine gland cell (parotid, rat)


RER + Lysosomes in human plasma cell cytoplasm	cytoplasm of a reticular cell of a human pharyngeal tonsil	cytoplasm of a human tonsil epithelial cell	sparse cytoplasm in a human lymphocyte	segmentonuclear neutro- phil granulocyte (human)	detail thereof: central cytoplasm	apical cytoplasm (vesicular gland, rat)


a monkey liver cell rich in organelles	peroxisomes, glycogen- granules (liver, monkey)	RER-rich cytoplasm, plasma cell (monkey)	cytoplasm with secretion vesicles, trachea (monkey)	parietal cell with intacellular se- cretion canaliculi, stomach (rat)	cytoplasm poor in organelles shows microtubuli, supporting cell (rat)	cytoplasm of a cell from adenohypophysis (Ratte)

The cytoplasm (Terminologia histologica: Cytoplasma) represents the contents of a cell, i.e. everything that is surrounded by the cell membrane but the nucleus. In other words the cytoplasm is the intracellular space with the fluid and all cell organells but not the nucleus. The cytoplasm has the following major components:
- the cell organells: rough and smooth endoplasmic reticulum, all kinds of vesicles, primary-, secondary- and telolysosomes, mitochondria, peroxisomes, multivesicular- and lamellar bodies, ribosomes, centriols, basal bodies, synaptic bodies;
- components of the cytoskeleton: microtubules, actin filaments, intermediate filaments;
- crystals and paracrystalline structures: glycogen granules, crystals of proteins;
- lipid droplets
- the cytosol or hyaloplasm (Terminologia histologica: Cytosol = Matrix cytoplasmatica), i.e., the light and electron microscopically visible nearly transparent, homogenous component of the cytoplasm into which all all other structures are embedded. The major component of this sol-like fluid is water (~ 66%). Thousands of proteins, enzymes, carbohydrates, lipids, messenger ribonucleic acids (m-RNA) and a vast amount of transfer ribonucleic acids (t-RNA) as well as ions are soluted or hydratised or just surrounded by this water. The most important enzymes of the cytoplasm are L-lactate-dehydrogenase, aminoacyl-t-RNA-synthase and the enzymes of glycolysis.

**Concentration of Ions**
in intracellular space (**ICS**)
& extracellular space (**ECS**)
cations :			anions:
Ion	ICS	ECS	Ion	ICS	ECS
Na⁺	10	142	Cl ^-	8	120
K⁺	155	4	HCO₃^-	10	27
free Ca⁺⁺	<0,001	2,5	HPO₄^{- -}	65	1
Mg⁺⁺	15	0,9	SO₂^{- -}	10	0,5
			organic acids	2	4
			proteins	2	2

(given in millimol per litre; mean values, deviations depending on cell type and functional state)
Function:
Uncountable amounts of enzymatic mediated reactions take place at the same time in several locations and compartments of the cytoplasm. The synthesis of proteins on free and RER-bound ribosomes which is the translation of the genetic information carried by the m-RNA with help of t-RNA, which provides the required amino acids, plays a key role in cellular function. Other cytoplasmatic processes of major importance are glycolysis, pentose-phosphate-pathway reacions, fatty-acid de-novo synthesis, synthesis of purin, pyrimidin and glycogen, transamination of amino acids and biosyntesis of cholesterin. Further the cytoplasm stores several substances e.g., fats and glycogen.

--> Electron microscopic atlas Overview
--> Homepage of the workshop

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