Pseudopodium

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pseudopodium

[‚süd·ə′pōd·ē·əm]
(botany)
A slender, leafless branch of the gametophyte in certain Bryatae.
(cell and molecular biology)
Temporary projection of the protoplast of ameboid cells in which cytoplasm streams actively during extension and withdrawal.
(invertebrate zoology)
Foot of a rotifer.

Pseudopodium

 

a temporary protrusion of cytoplasm in unicellular organisms (rhizopods, some flagellates, sporozoans, and myxomycetes) and in some multicellular organisms (leukocytes; macrophages; the eggs of sponges, coelenterates, and acoelomate tubellarians; some cells in tissue cultures).

Pseudopodia aid in amoeboid locomotion and enable the organisms to grasp food or foreign particles. Since the pseudopodia can appear and be withdrawn again in different parts of the cell, the shape of the cells in amoeboid locomotion is constantly changing. The formation of pseudopodia and amoeboid locomotion result from local changes in the surface tension of the cell and from little-studied mechanisms of overflow, contraction, extension, and liquefaction of the cytoplasm.

In amoebas, the pseudopodia are lobed or filiform. In foraminiferans and radiolarians, they are branched, thin, and long, and they coalesce with one another. The pseudopodia of sun animalcules contain a solid, elastic axial filament (axopodium), which is responsible for the flexibility and constancy of the shape of the organisms. The pseudopodia are usually digitiform or lobed in the amoeboid cells of multicellular organisms.

REFERENCE

Seravin, L. N. Dvigatel’nye sistemy prosteishikh. Leningrad, 1967.
References in periodicals archive ?
A pseudopod is put forth; one can either disagree with it and oppose it or join it and help society flow into it.
It moved slowly by sticking out tentative fingers of itself (we learned these projections were called pseudopods) and now and again simply flowed all of its blob into one of the pseudopods while abandoning and withdrawing from the others.
The amoeba of the law puts out new pseudopods as precedents are overturned, cases are heard in equity, and juries nullify bad laws or laws that don't properly apply to the facts.
The present study observed that pretreatment of rat neutrophils with Iso resulted in a decrease of ruffles and pseudopods on the surface of rat neutrophils stimulated with PMA, indicating the possibility that Iso has an inhibitory effect on the migration and phagocytosis of neutrophils.
Trophozoites showed very active movement, with wide pseudopods of rapid formation.
In this instance, cell locomotion is driven by the localised growth of a dynamic protein scaffold pushing against the cell membrane from the inside," says Dr Tyson, continuing, "Cells employ complex regulation, linked to environmental sensing, to make pseudopods highly accurate steering devices, which are of limited power though.
Atypical lymphocyte morphology, including pseudopods, split nuclei, and cytoplasmic granules, was observed in 5% of the birds.
Atypical lymphocyte cell morphology was observed in 5% (n = 8) of adult geese; these morphologies included split nuclei (Fig 1), pseudopods (Fig 2), and/or purple cytoplasmic granules (Figs 3 and 5).
Forams are abundant in present-day ocean sediments, where they use fingerlike extensions called pseudopods to engulf prey and to explore their surroundings.
Some samples were also treated with a drug that prevented the forams from sending out pseudopods.
The commonly reported mechanisms are decreased life span of platelets due to immunological and non-immunological mechanisms, elevated macrophage colony stimulating factors causing platelet destruction; ultra structural changes like centralization of dense granules, glycogen depletion, formation of pseudopods, and micro aggregation; consumption by diffused intravascular coagulation (DIC) host oxidative stress through oxidization of membrane lipids causing changes in fluidity and permeability of the cell membrane and its effect on fragility (2,3).
Positive allergic reaction was defined as wheal with pseudopods within 5 minutes of injection, which persisted for at least 20 minutes, and was accompanied by localized itching.