The thymus is positioned in the upper chest cavity above the heart. Thymus. The thymus gland is the main organ of the lymphatic system. Located in the upper chest region, the primary function of this gland is to promote the development of specific cells of the immune system called T lymphocytes. T lymphocytes or T-cells are white blood cells that protect against foreign organisms (bacteria and viruses) that have managed to infect body cells.
How long does it take for the Earth to rotate on its own axis ? The time it takes the Earth to rotate once is called a day (24 hours). The actual rotation time is a little less, about 23 hours and 56 minutes. Why do we have Day and Night?
We spend our lives on a spinning globeâit takes only 24 hours to notice that, as night follows day and the cycle repeats. But what causes Earth to rotate on its axis? The answer starts with the forces that formed our solar system. A fledgling star gathers a disk of dust and gas around itself, says Kevin Luhman, an assistant professor of astronomy at Penn State.