A pseudopod or pseudopodium (plural: pseudopods or pseudopodia) is a temporary arm-like projection of a eukaryotic cell membrane that are developed in the direction of movement. Filled with cytoplasm, pseudopodia primarily consist of actin filaments and may also contain microtubules and intermediate filaments. Pseudopods are used for motility and ingestion. They are often found in amoebas.
Different types of pseudopodia can be classified by their distinct appearances. Lamellipodia are broad and thin. Filopodia are slender, thread-like, and are supported largely by microfilaments. Lobopodia are bulbous and amoebic. Reticulopodia are complex structures bearing individual pseudopodia which form irregular nets. Axopodia are the phagocytosis type with long, thin pseudopods supported by complex microtubule arrays enveloped with cytoplasm; they respond rapidly to physical contact.However some pseudopodial cells are able to use multiple types of pseudopodia depending on the situation: Most of them use a combination of lamellipodia and filopodia to migrate (e.g. metastatic cancer cells). The human foreskin fibroblasts can either use lamellipodia- or lobopodia-based migration in a 3D matrix depending on the matrix elasticity.Generally, several pseudopodia arise from the surface of the body, (polypodial, e.g. Amoeba proteus), or a single pseudopod may form on the surface of the body (monopodial, e.g. Entamoeba histolytica).Cells which make pseudopods are generally referred to as amoeboids.
Of or relating to a pseudopod or to pseudopodia.