List of abbreviations

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

neutrophilic granulocyte with pseudopods (monkey)	B-lymphocytes with small pseudopods (rat)	thrombocytes also have pseudopods (rat)	a macrophage moves through connec- tive tissue using its pseudopods (rat)	human mast cell with long, thin pseudopods	monocyte in blood with short pseudopods (rat)

human eosinophilic gra- nulocyte with pseudopods	similar human eosino- philic granulocyte	human neutrophil protrudes its pseudopodfor phagocytosis	human mast cell with thin pseudopods 1	human mast cell with thin pseudopods 2

Pseudopods (Terminologia histologica: Pseudopodia) are foot-like elongate thin mobile processes of cells containing cytoplasm and actin filaments. They are no straight protrusions but much more irregularly formed than microvilli. Pseudopods may arise from cytoplasmwithinfew minutes and may also be retracted in similar time. Pseudopods are actively mobile since they contain actin as well as myosin filaments. Due to oriented polymerisation and depolymerisation of actin filaments in the anterior part of a pseudopod a short-time adhaesion of the cell membrane to extracellular structures and contraction of the posterior part of the cytoplasm in case of disattachment in the posterior part of established contact points of the cell to surrounding structures the whole cell is drawn forward by the pseudopod. Hereby myosin 1 binds the cytoskeleton to actin filaments which polymerise anteriorly, i.e. which further grow in this direction. In the intermediate part contractile stressfibres (Terminologia histologica: Fibrae tensionis) consisting of actin filaments and interposed myosin 2 bind to cell-matrix contacts. Contraction of the stress fibres then together with alterations of the cytoskeleton result in a shortening of the cell which anteriorly as mentioned is attached to adjacent matrix via outgrowing pseudopods which altogether results in anterograde movement. Thus pseudopods allow the cell to move actively whereby the velocity of this movement is influenced by  temperature, local concentration of ions and pH value changes as well as by chemotactic substances. Neutrophilic granulocytes can migrate with a speed of 20 to maximal 60 µm in a minute.
Occurrence:
The following cells are able to migrate via pseudopods: free cells in connective tissues: plasma cells, macrophages, eosinophilic granulocytes, mast cells; blood cells: all kinds of granulocytes, lymphocytes, monocytes.
Further, pseudopods are important for phagocytosis of macrophages: pseudopods protrude in direction of a foreign body, e.g. a bactrium, reach it, embrass it and finally by contraction draw it into the cell while the pseudopods fuse with each other before the phagocytosis is finished.

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