L4. Aerospace physiology

Question 1

What are the three main physiological challenges of aerospace travel?

Answer 1

Hypoxia, radiation, and microgravity

Question 2

What is the significance of Boyle’s Law in aerospace physiology?

Answer 2

It explains gas expansion and pressure-volume changes during altitude shifts

Question 3

How is cabin pressure managed in commercial aircraft?

Answer 3

Cabins are pressurized to mimic altitudes of 5000–8000 ft to balance engineering and physiological needs

Question 4

What is the typical cabin pressure equivalent in commercial flights?

Answer 4

5000–8000 ft

Question 5

What are the symptoms of tension pneumothorax in flight?

Answer 5

Severe chest pain, dyspnea, and cardiovascular collapse

Question 6

What causes hypoxia during air travel?

Answer 6

Reduced oxygen partial pressure at high altitudes

Question 7

How is hypoxia studied in simulated flight conditions?

Answer 7

By exposing participants to hypoxic conditions in chambers or real flight

Question 8

What experiment demonstrated ventilatory acclimatization to mild hypoxia?

Answer 8

Fatemian et al showed increased ventilatory sensitivity to hypoxia after 8 hours of exposure

Question 9

What are the cardiovascular risks for passengers with pre-existing conditions during flights?

Answer 9

Increased risk of pulmonary hypertension and hypoxia-induced stress

Question 10

What is the role of erythropoietin in response to mild hypoxia?

Answer 10

Stimulates red blood cell production to counteract oxygen deficiency

Question 11

What are the primary physiological challenges of microgravity?

Answer 11

Vestibular disturbances, fluid redistribution, and muscle and bone atrophy

Question 12

How is bone loss managed in astronauts during long-duration spaceflights?

Answer 12

Through resistance and weight-bearing exercises

Question 13

What is the cause of ‘space adaptation syndrome’?

Answer 13

Disruption of balance due to altered gravitational forces

Question 14

What did the Buckey study reveal about central venous pressure in space?

Answer 14

Central venous pressure decreases contrary to expectations

Question 15

How do parabolic flights simulate microgravity?

Answer 15

By creating weightlessness during freefall at the top of a parabolic arc

Question 16

What is the impact of radiation on astronauts during space travel?

Answer 16

Increases risk of cancer and acute radiation syndrome

Question 17

What findings suggest that age affects pulmonary vascular responses to hypoxia?

Answer 17

Older individuals show greater pulmonary artery pressure rises during hypoxia

Question 18

What is the role of the vestibular system in space sickness?

Answer 18

Senses acceleration and movement, disrupted in microgravity leading to space sickness

Question 19

What are the cardiovascular effects of high G-force experienced during suborbital flights?

Answer 19

Increased heart strain, pulmonary pressure, and desaturation

Question 20

What safety concerns are associated with commercial space tourism?

Answer 20

Loss of consciousness and cardiovascular strain during high G-forces

Question 21

What experiment demonstrated the increase in pulmonary pressure during commercial flights?

Answer 21

Smith et al showed pulmonary pressure increases even with mild desaturation

Question 22

How does fluid redistribution in microgravity affect astronauts?

Answer 22

It leads to cephalic fluid shift, causing facial puffiness and nasal congestion

Question 23

What countermeasures are used to combat muscle atrophy in space?

Answer 23

Treadmill, cycling, and advanced resistance exercise devices

Question 24

What is the ‘Garn scale’ and what does it measure?

Answer 24

A scale for measuring severity of space adaptation syndrome, named after Senator Jake Garn

Question 25

What role do hyperbaric chambers play in aerospace physiology research?

Answer 25

They mimic altitude and pressure changes to study physiological responses

Question 26

How do centrifuge studies simulate the effects of high G-force?

Answer 26

By exposing participants to acceleration profiles similar to those of suborbital flights

Question 27

What was the outcome of Buckey's central venous pressure experiments in space?

Answer 27

Central venous pressure decreases unexpectedly in microgravity

Question 28

How do changes in cephalic fluid shift manifest visually in astronauts?

Answer 28

Engorged veins and puffiness due to lack of gravitational pull

Question 29

What is 'Spaceflight Associated Neuro-ocular Syndrome' (SANS) and its implications?

Answer 29

A syndrome causing optic disc swelling and vision changes, affecting astronauts

Question 30

What are the challenges of radiation exposure for long-term space missions?

Answer 30

It poses risks of acute syndrome and long-term cancer during Mars missions

Question 31

How did Tom Smith's research contribute to understanding hypoxia in flight?

Answer 31

Demonstrated pulmonary artery pressure increase during hypoxia exposure

Question 32

What findings suggest that pulmonary vascular pressure increases even in mild hypoxia?

Answer 32

Older participants had greater rises in pulmonary pressure compared to younger ones

Question 33

What safety guidelines are recommended for patients with respiratory diseases planning to fly?

Answer 33

Hypoxic challenge tests to predict in-flight oxygen needs

Question 34

What was revealed about blood oxygenation during high G-force simulations?

Answer 34

Desaturation to 80% observed under simulated high G and hypoxic conditions

Question 35

How are suborbital flight profiles simulated for physiological research?

Answer 35

Acceleration profiles recreated using advanced centrifuges

Question 36

What is the significance of erythropoietin spikes in frequent flyers?

Answer 36

Mild hypoxia triggers erythropoietin increases, potentially impacting frequent flyers

Question 37

What are the long-term cardiovascular effects of chronic microgravity exposure?

Answer 37

Reduced arterial stiffness and vascular remodeling over long exposure

Question 38

How does microgravity impact the vestibular system during extended missions?

Answer 38

Causes space sickness, resolved with time and adaptation

Question 39

What adaptations are essential for reducing radiation risks on Mars missions?

Answer 39

Shielding and mission planning to avoid peak solar radiation events

Question 40

What are the implications of fluid redistribution for cardiovascular function in space?

Answer 40

Altered venous return and cardiac preload due to lack of gravity