Its been a while I've made a post on this blog, I've been busy with academics and host of other activities. On Saturday, writing my exams (Respiratory Physiology), one of the questions posed at us was "Discuss the effects of space physiology". While answering the question it dropped on my mind to share my knowledge with friends and beloved followers.
Just Before You Take That Step
Implications of Space Travel
Becoming an astronaut might be one of the many wishful dreams of many secondary school leavers largely due to what is brought to the fore in movies, news report, group discussions, etc.
Space physiology, studies physiological responses of the body in space and space crafts with three major differences between environment on earth and space are atmosphere (temperature, humidity and gas composition), radiation and gravity in mind.
Implications of Space Travel
Weightlessness, otherwise called microgravity, is a major physiological problems faced by astronaut in space which inherently leads to other physiological disturbances including:
*Motion sickness, characterized by nausea, vomiting, headache and malaise (generalized feeling of discomfort or illness associated with sensation of exhaustion)
*Translocation of body fluid due to failure of gravity to cause normal hydrostatic pressure
*Diminished physical activity because no strength of muscle contraction us required to oppose the force of gravity.
Apart from the aforementioned physiological disturbances associated with microgravity, specific systems in the body are affected. They include:
1. Cardiovascular disconditioning: Due to fluid shift, blood moves from the lower part to upper part of the body resulting in enlargement of the heart. In other to compensate this change, the kidneys excrete large amount of fluid causing a decrease in blood volume (also called space anemia) and the heart need not pump blood against gravity in space.
FACT! The kidneys excrete electrolytes along with water as a result the osmolarity of body fluid is not altered-no raised concentration. Therefore, astronauts don't feel thirsty in space because the thirst centers (in the hypothalamus of the brain) is not stimulated.
There is also reduced work capacity, impairment of baroreceptor reflex and reduced orthostatic changes resulting in the non-upright posture of astronauts even after returning to earth.
2. Damage to the musculoskeletal system: Studies show that about 1.0 percent of bone mass is lost each month in an astronaut in space implying that calcium and phosphate from bone is excreted in urine resulting in loss of bone mass. Reason being that, astronauts move by floating instead of using their legs consequently there is loss in muscle mass and muscle strength. The endurance of the muscles also decreases. Bones becomes weak and osteoclastic activity increases during space travel.
There you have it, so think twice before taking that giant step of becoming an astronaut.
I'm sure you've gained one or two things, don't forget to share.
