The glottis, consisting of two bands of tissue known as the true vocal cords. When air is exhaled against the true vocal cords, they vibrate and create sounds. The greater the air pressure, the louder the sound. Pitch is controlled by the speed of vibration. Since the vocal cords in men are usually thicker and longer than in women, they vibrate more slowly, creating a lower pitch or deeper-sounding voice.
Cancer is really a number of diseases caused by the abnormal growth of cells.
Normally, the cells that make up the body divide and reproduce in an orderly manner, so that we can grow, replace worn-out tissue, and repair any injuries. Sometimes, however, cells get out of control. They divide too much and form masses known as tumors. Some tumors may interfere with body functions and require surgical removal, but do not spread to other parts of the body. These are known as benign tumors.