SCI Vs Astronauts

Scott et al. compared those who suffer from spinal cord injury (SCI) and the body under microgravity. Their findings show that SCI patients and astronauts, in long term conditions, have similar physiological outcomes and those who have SCI can be good examples to study the effects of spaceflight on the human body. The importance of comparing and contrasting these two populations is to be able to see if scientists can test individuals of one group to come up with results and conclusions of how to treat symptoms occurring in the other. Both groups experience orthostatic intolerance (OI), but astronauts show an increase in muscle sympathetic nerve activity. Conditions experienced by astronauts in microgravity are usually reversible, whereas in individuals with SCI often have irreversible symptoms/conditions. Two things that …show more content…
When they first enter microgravity, they lose about 800 mL of net volume. The biological stress on astronauts and their bodies causes the increase of two hormones: ACTH (adrenocorticotropic hormone) and antidiuretic hormone. ACTH, as learned earlier in the semester, is a hormone secreted by the anterior pituitary gland and released in response to stress from the body. Recall that when our sympathetic nervous system is “turned on”, other activities in our body get put on the “back burner”, such as the body recognizing whether we are hungry or not, which will eventually lower food intake, that is, until they adapt to weightlessness (around day 3). Antidiuretic hormone, also called vasopressin, is primarily used to retain water inside the body and to constrict the blood vessels. More of it may be released due to decreasing low plasma volumes. When more of this hormone is produced, the need to drink water is less obvious, since it will cause the kidneys to retain more water. By day 5, plasma volume decreased by 20%, which is another cause of orthostatic