Orthostatic hypotension (also called postural hypotension) is a sudden fall in blood pressure that occurs upon standing quickly. Blood pressure is the force of your blood against the walls of your arteries (the blood vessels that carry blood from the heart through the body). Hypotension is the term for low blood pressure. When you stand up, gravity pulls blood into your legs, and your blood pressure begins to fall. Certain reflexes in your body compensate for this change. Your heart beats faster to pump more blood, and your blood vessels constrict to prevent blood from pooling in your legs.
There are literally thousands of man made objects in space, such as parts of old space rockets sent up by Russia, China, Europe and the USA etc, lots of military and civilian satellites used for communication, navigation, research and reconnaissance, space probes sent to explore planets like Mars, the Hubble Space Telescope used to look deep into ...
The names of some man-made satellites are Sputnik 1, Explorer 1, the International Space Station, ORBCOMM FM-107, Gonets-19 and SES-8. In 1957, Russia launched the first man-made satellite called Sputnik 1, and the United States sent Explorer 1 into orbit in 1958.