Human body changes in space

Some Major Human Physiological Changes Resulting from Extended Travel in Earth Orbit

Musculoskeletal System

Loss of bone mineral density

Loss of skeletal muscle

Cardiovascular System

Orthostatic hypotension

Loss of hydrostatic pressure

Pulmonary System

Changes in pulmonary circulation and gas exchange

Alimentary System

Ileus

Decrease in absorption or malabsorption

Nervous System

Ataxia

Motion sickness

Disturbed fine motor and gross motor functions

Altered sleep-circadian rhythm and sleep deprivation

Reproductive System

Effects of radiation on gametes

Urinary System

Renal calculi

Hematological and Immunological Systems

Anemia

Potential immunologic depression

Source: Billica, 2000.

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Source: https://www.ncbi.nlm.nih.gov/books/NBK223785/




TABLE : Path Roadmap Project: Critical Risks. SOURCE: Charles, 2000

https://www.ncbi.nlm.nih.gov/books/NBK223785/
LossCardiovascular AlterationsHuman Behavior and PerformanceImmunology, Infection and HematologyMuscle Alterations and AtrophyAcceleration of age-related osteoporosis Human performance failure because of poor psychosocial adaptation
Fractures (traumatic, stress, avulsion), and impaired healing of fractures Occurrence of serious cardiac dysrhythmias Human performance failure because of sleep and circadian rhythm problems Loss of skeletal muscle mass, strength, or endurance
Impaired cardiovascular response to orthostatic stress Inability to adequately perform tasks due to motor performance problems, poor muscle endurance, and disruptions in structural and functional properties of soft and hard connective tissues of the axial skeleton
Inability to sustain muscle performance levels to meet demands of performing activities of various intensities
Neurovestibular AdaptationRadiation EffectsClinical CapabilityOther
Carcinogenesis caused by radiation Trauma and acute medical problems Severe Risks
Disorientation and inability to perform landing, egress, or other physical tasks, especially during/ after g-level changes Damage to central nervous system from radiation exposure Toxic exposure Inadequate nutrition (malnutrition) (three risks) Very Serious Risks
Impaired neuromuscular coordination and/or strength Synergistic effects from exposure to radiation, microgravity and other environmental factors Altered pharmacodynamics and adverse drug reactions Postlanding alterations in various systems resulting in severe performance decrements and injuries
Early or acute effects from radiation exposure Habitation and life support (eight risks)
Bone LossCardiovascular AlterationsHuman Behavior and PerformanceImmunology, Infection and HematologyMuscle Alterations and Atrophy
Injury to connective tissue or joint cartilage, or intervertebral disc rupture with or without neurological complications Diminished cardiac function Human performance failure because of human system interface problems and ineffective habitat and equipment design, etc. Immuno-deficiency/ infections Propensity to develop muscle injury, connective tissue dysfunction, and bone fractures due to deficiencies in motor skill, muscle strength, and muscular fatigue
Renal stone formation Manifestation of previously asymptomatic cardiovascular disease Human performance failure because of neurobehavioral dysfunction Carcinogenesis caused by immune system changes
Impaired cardiovascular response to Altered hemo-and cardio-dynamics from altered blood components Impact of deficits in skeletal muscle exercise stress structure and function on other systems
Altered wound healing Altered host-microbial interactions Allergies and hypersensitivity reactions
Neurovestibular AdaptationRadiation EffectsClinical CapabilityOther
Impaired cognitive and/or physical performance due to motion sickness symptoms or treatments, especially during/ after g-level changes Radiation effects on fertility, sterility and heredity Illness and ambulatory health problems Serious Risks
Vestibular contribution to cardioregulatory dysfunction Development and treatment of decompression illness complicated by microgravity-induced deconditioning
Possible chronic impairment of orientation or balance function due to microgravity or radiation



Difficulty of rehabilitation following landing (two risks)




Squashed eyeballs

You need perfect 20/20 vision in order to become an astronaut

Did you know that squashed eyeballs were a big problem for astronauts?
It may sound weird but many astronauts come back from space with worse vision than when they left.


High pressure in zero-gravity has also lead to some astronauts struggling to read and even conduct experiments while in space.

Now Nasa is designing special sleeping bags to try and avoid it.

The idea is for the bags to suck liquid from an astronaut's head down to their feet, in order to avoid eye problems developing on long missions.



Genetic clues

The Ottawa team recruited 14 astronauts who spent at least six months on the International Space Station, collecting 10 blood samples from each individual beginning 90 days before departure and continuing throughout the year after they returned Earthside, since the impacts of space travel can persist long after missions are completed.

Laneuville used these samples to track how white blood cells turned genes on and off during space travel. These gene changes help control how well white blood cells can fight off pathogens. This type of analysis, known as transcriptomics, could provide information on the genes that the white blood cells used to respond to microgravity, which could provide clues about overall immune function.

Within days of arrival on the ISS, study participants all showed a sharp decline in the activity of many immune-related genes. At months two and four on the ISS, some of these changes began to normalize. They didn’t return to baseline, however, until several months after the astronauts got home. It’s a very clear and unique pattern, Laneuville says.

“I was not expecting such a large change in gene expression. Why would the immune system go down in microgravity?” she wonders. “There seems to be something special about space.”

To Evagelia Laiakis, a radiation biologist at Georgetown University, the long follow-up was extremely important.

Laiakis’s own work exposes mice to radiation analogous to the cosmic rays that astronauts can encounter as they leave Earth’s protective magnetic field. The research has shown that the radiation caused changes to the mice’s ability to repair DNA and use energy effectively. Even more worrying, the changes persisted for four months, equivalent to 10 to 20 years in humans.

“It was very surprising,” Laiakis says. “There were some persistent changes, with the mice never really returning back to normal with a low dose of our space-related radiation.” As humans venture farther into space, exposure to radiation could compound the genetic changes caused by microgravity.

Laneuville is currently investigating whether people in bedrest studies show similar gene expression changes. If she can identify people at high risk for deconditioning, whether in hospital rooms or on future flights to Mars, Laneuville hopes to stop the effects before they begin.