Cell membrane presses against cell wall, but the cell wall is what gives the cell shape
Nerve Regulators: Two types of nerves help to control the action of the digestive system. Extrinsic (outside) nerves come to the digestive organs from the unconscious part of the brain or from the spinal cord. They release a chemical called acetylcholine and another called adrenaline
Microtubules are composed of two different types of tubulin. Namely, these simpler units are called alpha-tubulin and beta-tubulin. These subunits are essentially tightly bound together to form heterodimers. In the microtubule structure, they are arranged in an organized manner in such a way that they in parallel direction with protofilaments.
