The diaphragm is the large dome-shaped muscle that rests right under the lungs and separates the abdominal cavity from the thoracic cavity. The contractions of the diaphragm are what truly facilitate the movement of air in and out of the lungs. The contraction of the diaphragm, or breathing in, leaves more room in the chest cavity for the lungs to expand as the diaphragm "tightens". The expanded lungs are filled with oxygen-rich air which is then is diffused through capillaries to different parts of the body. The process of breathing out occurs when the diaphragm relaxes, slowly resuming its position its original position in the chest cavity. When relaxing, carbon dioxide is forced out of the lungs.
During inhalation, the diaphragm contracts and moves downward, increasing the space in the chest cavity. Air is sucked in through the nose and mouth and eventually travels to the lungs, which expand.
During exhalation, the diaphragm relaxes and moves upward, reducing the space in the chest cavity. This forces carbon dioxide out of the lungs through the nose and mouth.
Heat can be transferred from one place to another by three methods: conduction in solids, convection of fluids (liquids or gases), and radiation through anything that will allow radiation to pass. The method used to transfer heat is usually the one that is the most efficient.
The answer is Ejaculation. It is the discharge of semen from the male reproductive tract with an orgasm. It causes the peristaltic contraction of the reproductive duct and some accessory gland. The smooth muscle sphincter closes and semen moves into urethra.
