HOW CELLS ARE ABLE TO MOVE
Cells are able to move through a process called cell motility, which is crucial for various biological functions such as embryonic development, immune response, wound healing, and tissue formation. There are several mechanisms through which cells achieve movement, including cytoskeleton dynamics, cell adhesion, and cellular protrusions.
1) Cytoskeleton Dynamics: The cytoskeleton, a network of protein filaments within the cell, plays a fundamental role in cell movement. It consists of three main components: microfilaments (actin filaments), intermediate filaments, and microtubules. Actin filaments are particularly involved in cell motility by providing structural support and generating forces for movement. The dynamic assembly and disassembly of actin filaments allow the cell to change shape and move in response to various signals.
2) Cell Adhesion: Cell adhesion is another critical aspect of cell movement. Cells adhere to their surrounding environment through specialized structures such as focal adhesions and adherens junctions. These adhesion complexes link the cytoskeleton to the extracellular matrix or neighboring cells, providing traction for the cell to pull itself forward during movement.
3) Cellular Protrusions: Cells can extend cellular protrusions such as lamellipodia, filopodia, and pseudopodia to facilitate movement. Lamellipodia are broad, sheet-like extensions rich in actin filaments that help propel the cell forward. Filopodia are slender protrusions involved in sensing the environment and guiding the direction of movement. Pseudopodia, commonly observed in amoeboid cells, are temporary protrusions used for crawling and engulfing particles.
