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?
The Earth rotates around its axis once every 24 hours. It also revolves around the Sun once every 365.25 days. The axis of Earth's rotation is tilted 23.5 degrees from the plane formed by its orbit around the Sun. Figure 1 shows the axial tilt of Earth, with respect to its orbit.Figure 1. Earth's axial tilt. The angle of tilt equals the angle between the axis of rotation (through the poles) and a line that is perpendicular to the plane of the orbit.The celestial equator is an extension into space of Earth's equator.he angle of tilt equals the angle between the axis of rotation (through the poles) and a line that is perpendicular to the plane of the orbit. The celestial equator is an extension into space of Earth's equator.