Microtubules are hollow cylindrical structures made up of globular proteins, alpha, and beta tubulins. With a diameter of twenty-five nanometers, they are the thickest cytoskeletal elements. They originate from microtubule organizing centers or MTOCs and associate in linear rows to form structurally polar protofilaments with plus and minus ends. The minus-end is the alpha-tubulin outward-facing end from where the microtubule polymerizes in the MTOC. The plus-end is the beta-tubulin outward facing end where new tubulin dimers can bind. Microtubules act as tracks for plus-end headed kinesin and minus-end headed dynein to transport various cargoes and vesicles from one part of the cell to another. Microtubules also bind different microtubule-associated proteins and other cytoskeletal proteins like microfilaments and intermediate filaments to maintain the cell shape and architecture. During cell division, the microtubules help form the complex spindle apparatus. The spindle apparatus, along with the motor proteins, segregates chromosomes to the daughter cells.