![]() Take gravity away and the blood pressure equalizes around 100 mmHg throughout our body. In the brain however, the pressure is only 60 to 80 mmHg. While standing, the blood pressure in our feet is as high as 200 mm Hg (millimeters of mercury). Gravity ensures that the blood in our body maintains an optimum blood pressure level. Take gravity away and we can no longer figure out where the ground and ceiling are! The vestibular apparatus in the human ears is designed to work with earth's gravity and provides sensory information about motion, equilibrium, and spatial orientation. We can sense the direction and speed of linear acceleration (speed changes without change in direction) due to the otolith organs while the semicircular canals allow us to sense the direction and speed of angular acceleration (speed changes along with change in direction). The vestibular system, which is situated in the ears, is comprised of otolith organs and semicircular canals. The dizziness or difficulty in walking we experience after spinning around in a circle, clearly demonstrate what happens when we lose this sense even for a few moments. However, loss of gravity negatively impacts this spatial perception. Together, these senses constantly collect and interpret data from all over the body. This requires the precise integration of our body's sensory and response systems including visual, vestibular, somatosensory (pressure and stretch receptors in our skin), and auditory. ![]() Walking a tightrope, pirouetting in a ballet performance, or twisting while diving, all showcase our vestibular system as it actively keeps track of the position of our arms and legs and enable us to perform these tricks without losing balance. Besides the five main senses (smell, touch, sight, taste and hearing) we humans possess, there is one more powerful sense called the vestibular sense that enables our body to sense movements and use it to maintain balance. The high level of calcium in the blood also reflects a high level of bone mass loss which makes the bones weak and increases the risk of fracture.Īll organisms on earth have sensory and response systems with which they respond to internal and external stimuli. Increased levels of calcium in the blood, lead to a higher incidence of renal stones. This breaks down calcium that is normally stored in bones, and releases it into the bloodstream. While making any movements, the bones are not subjected to the same level of stress they would have otherwise endured while on earth. While in space, the amount of weight the bones must support gets reduced to zero. Fewer bone building cells result in a loss of bone mass. Lack of stress on the bones reduces the formation of bone building cells called osteoblast cells. Although the exact trigger is unknown, scientists believe that the reduced stress on bones may be responsible for progressive bone loss, a condition most commonly seen in patients confined to beds due to long term illnesses or old age. This lack of the gravitational pull alleviates the mechanical strain otherwise endured by our skeletal system. ![]() The human body tends to relax in a state of weightlessness because it no longer fights the pull of gravity. Without the downward pull of gravity, our body cannot function properly. However, it is important to note that extended exposure to zero gravity is dangerous to our health. Occasional trips to the amusement park for a gravity-defying ride will not harm anyone. Astronauts experience weightlessness at this point and tend to float the ultimate roller coaster thrill every little child dreams of. This cancels out the effect of both forces and results in a state of zero gravity. ![]() In other words, the gravitational pull felt by the spacecraft becomes equal to the centrifugal force exerted on the spacecraft. When a spacecraft orbits the earth, the acceleration of the spacecraft, known as the centrifugal force, counterbalances the earth's gravity and neutralizes the gravitational force. A state of apparent weightlessness, zero gravity is best experienced in outer space. Zero gravity can be defined as a state of weightlessness, a condition when the gravitational force is zero. Remember that time you were upside down in a roller coaster and, for exactly one second, your body left contact with your seat? The moment of exhilaration that made waiting in the long queue for that ride completely worthwhile?
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |