Space (Mark Kelly reference)

List 6 possible physiological effects of short and long duration flight on the human body.

SMS (space motion sickness)

neurovestibular

cardiovascular

musculoskeletal

immune/hematopoietic system

behavioral/psycho-social

What are the incidence rates of SMS?

66-95% of all crewmembers

10% of all cases are severe

What are symptoms of SMS?

loss of apetite to nausea and vomiting

What is the timecourse of SMS?

onset: MECO - 24 hrs

peak: 24 - 48 hrs

resolve: 48 - 72 hrs

What are 4 possible causes of SMS?

relationship between orientation illusions and SMS

otolith organs asymmetry

sensorimotor conflict

fluid shift

Is SMS correlated with motion sickness on earth?

no

Is Preflight Adaption Training a reliable indicator of SMS?

it is promising but only for research purposes

What is the general problem that brings forth SMS?

head roll and pitch

What are the 3 categories of SMS?

mild, moderate, severe

What are some qualities of mild SMS?

1-2 transient symptoms

no operational impact

all symptoms resolved in 36-48 hrs

What are some qualities of moderate SMS?

several symptoms of persistent nature

minimal operational impact

all symptoms resolved within 72 hours

What is the current favorite treatment for SMS?

25-50mg IM injection of promethazine

1-G orientation

inactivity

preflight training and prophylaxis

how does a fluid switch happen from ground to space?

on ground: gravity exerts a downward force to keep fluid low in body

in space: blood tends to redistribute towards chest and upper body, body detects a “flood” in and around heart

How does the body react to the “flood” around heart in space?

it rids itself of the “excess” fluid and the heart decreases in size

What happens with respect to fluid shift when the body returns to earth?

fluid gets pulled downward by gravity, but there isnt enough fluid to function normally on earth

What are results in feeling from fluid-shifts when in space?

less thirsty

stuffy nose

urinate frequently

dull sense of taste

How does the fluid-shift affect the way people feel in space?

puffy face, small ah legs

Heart rate response to landing.

What is the incidence for muskuloskeletal affects in space?

all

What are some acute symptoms of musculoskeletal effects in space?

back pain (70% incidence in orbit)

fatigue (less flexibility and indurance)

What are some chronic symptoms of musculoskeletal effects in space?

muscle atrophy

bone demineralization (increased urine and fecal calcium)

skeletal changes have occured in animals and humans with exposure to microgravity from 7 to 237 days

What muscles experience a decrease in mass when in space?

antigravity

thigh, calf

What muscles are more affected in space (flexor or extensor)

extensor

What type of muscle fiber was found to increase in rats when exposed to microgravity?

Type II (fast) but prone to fatigue

What are some effects of long duration space flight on calcium metabolism?

kidney stones

possible fractures

disk disease

What are some treatments for acute musculoskeletal loss symptoms?

Stretching

Exercise

Penguin Suits

Fetal Position Sleep Strap

Medications: e.g. NSAID- Rx for discomfort

What are countermeasures for muscular strength and endurance preservation?

Aerobic (TVIS, CEVIS) and resistive exercise (RED)

NAC and other supplements/pharmacologies

What are some countermeasures for reduced bone strength/increased injury and fraction risk?

1) Resistive exercise hardware

2) Pharmacologic- e.g. Bisphosphonates

What are some countermeasures for urinary Calcium excretion/risk of calculi?

1) Increased Fluid Intake (2-3L/day)

2) Resistive exercise

3) Pharmacologic- e.g. inhibitor K+ Citrate or K+Mg+ Citrate

4) Contingency Management Strategy

What are some countermeasures that are currently under consideration?

1) Artificial gravity in transit

2) PTH, Peptides

What are examples of exercise countermeasures

Treadmill

• Neurovestibular

• Cardiovascular

• Musculoskeletal

Cycle Ergometer

• Cardiovascular

Resistive Exercise Device

• Musculoskeletal

How much of Scott’s gene expression shifted during flight?

~7%, but most returned to baseline when acclimating back to earth

How did scott’s telomeres shift?

lengthened during flight, but shortened quickly upon returning to earth

ended up shorter than baseline

How did scott’s cognitive function alter?

remain study but slowed a little post-flight amid readaptation to earth’s gravity

How did immune response alter for scott?

flu shot was given in space → no difference from marks on earth