Space Medicine

Question 0

The ___________ line, at an altitude of 62 miles (100 Km) above sea level marks the transition from Earth’s atmosphere to outer space. It is around this altitude that the thinness of the atmosphere does not support aerodynamic lift, thus vehicles will have to transition to reaction thrust to maintain control and keep the weight of the vehicle aloft.

Answer 0

Karman line

Question 1

At the current time, commercial space pilots are required to maintain a ___________class medical certificate administered by the FAA.

Answer 1

Second class certificate.

Question 2

The main physiologic stressors for participants of future commercial space flights are velocity and acceleration. A commerical space flight participant will have to re-enter the atmosphere, decelerate, and land. Acceleration forces are best tolerated when the direction (vector) of acceleration or deceleration is _____________.

Answer 2

Through the chest (Gx- front to back, back to front) (eyes in, eyes out).

Question 3

Space motion sickness can occur with the first 72 hours and affect upward of _______ percent of astronauts.

Answer 3

66-70%

Question 4

When experienced during the first flight, there is a _______ percent of getting space motion sickness on the second flight.

Answer 4

77%

Question 5

The most serious threat to health on long-duration, exploration class spaceflight missions is which of the following?

a) Cardiovascular deconditioning
b) Bone loss
c) Radiation exposure
d) Space motion sickness

Answer 5

C) Radiation exposure

Question 6

Echocardiography data shows a short-term change during the first 17 days of spaceflight of an increase in stroke volume by _____ %. Followed by a decrease of _________ percent at 1, 3, and 5 months.

Answer 6

46%.

10-16%.

Question 7

Postflight orthostatic intolerance occurs in _____ to ________ of the crew.

Answer 7

20 to 67%

Question 8

Astronauts height changes by as much as ________ on orbit.

Answer 8

5 to 6cm.

Question 9

Which of the following is NOT a measure used in the space shuttle program to mitigate the risk of orthostasis upon return to Earth?

a) loading with isotonic fluid prior to re-entry
b) extended G-suit inflation
c) flight deck crew seats reclined 30 degrees
d) mandatory exercise during extended missions
e) Use of cooling garments

Answer 9

c) flight deck crew seats reclined to 30 degrees

Question 10

In the microgravity environment atmospheric particle count is:

a) decreased due to lack of convection
b) decreased because the heavier particles settle out
c) about the same as in a 1-g operating room
d) increased due to lack of gravity
e) none of the above

Answer 10

d) increased due to lack of gravity

Question 11

Toxic exposures in the space shuttle are LEAST likely to be caused by:

a) crew metabolic products
b) hydrazine
c) non-metallic particles
d) payload chemicals
e) metals

Answer 11

e) metals

Question 12

Galactic Cosmic Radiation:

a) consists mostly of electons and high energy nuclei of heavier atoms
b) is of little consequence within spacecraft, but may be harmful during EVA’s.
c) consists of about 79% protons, and 20% helium nuclei (alpha particles)
d) at sea level has only 40% of ionizing power it has at 70,000 feet.

Answer 12

c) Consists of 79% protons and 20 % alpha particles

Question 13

One gray (GY) is the amount of radiation absorbed by the body quantified as___________.

Answer 13

one joule of energy absorbed per kilogram of body mass

Question 14

Space station atmosphere is:

Answer 14

14.7 or sea level atmosphere

Question 15

Theories on the etiology of space motion sickness include all EXCEPT:

a) gastrocolic distention
b) cephalad fluid shift
c) Treisman’s theory
d) Sensory conflict
e) otolith asymmetry

Answer 15

a) gastrocolic distention

Question 16

The excretory products of man which contribute to the gaseous pollution of the artificial gaseous atmosphere (AGA) in the spacecraft are released into the spacecraft from____________.

Answer 16

Lungs, hair, skin, GI tract, urinary tract, and mouth

Question 17

Ebullism or the boiling of body fluids occurs at an altitude known as _______________.

Answer 17

Armstrong’s Line- 63,000 feet

Von Karman’s line is at 62 miles where the atmosphere gives way to outer space.

Question 18

What is the purpose of ozone?

Answer 18

Ozone is formed when ultraviolet light around 2000 angstroms is absorbed by O2. Maximum concentration is found at 30 Km. Destruction of ozone by UV between 2100 and 2900 angstroms raises air temperature to a maximum of 35 degrees at a height of 50 Km. The primary biologic effect is the absorption of harmful UV light below 3000 angstroms, NOT cosmis ray attenuation.

Question 19

Inflight monitoring of the electrical activity of the heart revealed arrhythmias in the crew of the Apollo 15. These arrhythmias were a result of:

a) dehydration
b) hypoxia
c) potassium deficit
d) zero gravity

Answer 19

c) potassium deficit

Question 20

Animal and human experiments on the effects of ambient temperature on the physiologic response to acceleration have shown what?

Answer 20

That high temperatures reduce, and low temperatures increase the body’s resistance to accelerations.

Question 21

The gas or compounds that protect the earth from UV radiation below 3000 angstroms is/are:

a) oxygen
b) ozone
c) carbon dioxide
d) water vapor
e) a and b

Answer 21

e) a and b. Both oxygen and ozone protect the earth from UV radiation below 3000 angstroms.

Question 22

The greatest physiologic danger to manned orbital flights at distances of 500 to 50,000 miles from the earth’s surface is:

a) decreasing body weight and decreasing gravity
b) increasing temperature
c) decreasing temperature
d) increasing particle radiation

Answer 22

d) increasing particle radiation

Question 23

When loss of a protective shield and failure of deployed solar panels caused Skylab to heat up to 130 degrees, what unique thermal risk faced the first manning crew?

Answer 23

Absence of convective cooling. The lack of gravitational gradient produces atmospheric stasis, allowing no natural convection currents.

Question 24

The specialty of aerospace medicine, particularly when applied to spaceflight, is the practice of ______________.

Answer 24

Preventive Medicine

Question 25

What is the average approximate radiation exposure for a six month mission on the ISS, (56 degrees, 210 nautical miles)?

Answer 25

50 millirad per day

Question 26

It is postulated that astronauts have a higher risk of kidney stones. Which of the following could contribute to this risk?

a) reduced urinary calcium reduced urinary pH
b) increased calcium intake, elevated urinary pH
c) high protein intake, reduced fluid intake
d) increased serum uric acid, hypercalcemia

Answer 26

c) high protein intake, reduced fluid intake

Question 27

Characteristics of the stratosphere include:

a) temperature decreases in a linear fashion
b) temperature generally remains constant with increasing altitude
c) is the part of the atmosphere where weather occurs
d) extends up to 8-16km depending on the latitude
e) a, c, and d

Answer 27

b) temperature generally remains constant with increasing altitude

Question 28

The percentage of oxygen in the atmosphere remains constant up to about 90km, however hypoxia occurs with increasing altitude. The gas law that explains this hypoxia is:

a) Henry’s
b) Boyle’s
c) Charles
d) Dalton’s

Answer 28

D) Dalton’s. The total pressure of a gas mixture is equal to the partial pressure of each gas in the mixture.

Question 29

What is the significance of 63,000 feet?

Answer 29

It is the altitude at which the atmospheric pressure equals the vapor pressure of bodily fluids, known as Armstrong’s line. It is where Ebullism occurs.

Question 30

The increase in the lifetime cancer mortality for a mission to Mars is ____________.

Answer 30

1-3%

Question 31

When the astronaut experiences microgravity they become slightly hypovolemic with a decrease in preload. What causes this?

Answer 31

Plasma volume and total body water both decrease

Question 32

A common medical event in manned spaceflight is:

a) spatial disorientation
b) back pain
c) cardiac dysrhythmia
d) UTI
e) gastroenteritis

Answer 32

b) back pain

Question 33

The primary hazards of spaceflight are:

a) decompression
b) impacts
c) radiation hazards
d) medical hazards
e) microgravity hazards

Answer 33

c) radiation hazards

Question 34

What were the four late effects the NCRP focused on when creating radiation guidelines for NASA?

Answer 34

1) Genetic effects
2) fatal cancers
3) cataracts
4) gonadal infertility

Question 35

The concept of storm shielding in spaceflight refers to what?

Answer 35

providing an area of greater shielding against radiation from solar particlar events in order to protect the crew