Final Quiz-Microgravity, Body Composition and Human Performance Flashcards
What is the difference between zero-g and weightlessness?
Zero-g: When the force of gravity reaches an absolute value of zero
Weightessness: The effect of gravity is canceled by the intertial force resulting from orbital flight.
What are five basic strategies to simulate a microgravity environment?
-Head-down bed rest
-Wheelchair confinement
-Water immersion
-Immobilization and confinement
-Parabolic flights
Define orthostatic intolerance.
Compromised venous return to the heart during upright position in a gravity environment.
What does the decrease in total fluid volume do to the heart during the first few days microgravity?
Reduces total effort
What is NASA’s greatest biomedical concern?
The 1% per month loss in weight-bearing bone mass during space missions
Has permanent neuromuscular dysfunction been demonstrated during prolonged space missions?
No
What six systems are impacted during a microgravity environment?
-Cardiovascular
-Hematologic
-Fluis, electrolyte, hormonal
-Muscle
-Bone
-Neurosensory
How does microgravity effect the neurosensory system?
-Altered vestibular function
-Space motion sickness
-Altered sensory and balance information
What are four predominant exercise modes that have played an important role during in-flight workouts aboard space missions?
-Treadmill walking and running
-Cycle ergometry
-Leg rowing
-Upper and lower multijoint dynamic resistance exercise
Besides resistance and endurance training, what are other countermeasure strategies to to help minimize micro-gravity induced orthostatic intolerance?
-Fluid loading
-G-suit inflation
-Artificial gravity
-Pharmacologic agents
What is the formula for BMI?
Body mass (kg)/Stature (m2)
What is storage fat called?
Adipose tissue
The rationale for using skinfolds to estimate body fat comes from the interrelationships among what three factors?
-Adipose tissue directly beneath the skin (subcutaneous fat)
-Internal fat
-Whole-body density
What are the common anatomical sites for skinfold measurements?
-Suprailiac
-Triceps
-Subscapular
-Abdominal
-Upper thigh
What is fat patterning?
Refers to the distribution of body fat on the trunk and extremities.
What affects bioelectrical impedance analysis?
Hydration and skin temperature
How does hypo and hyperhydration affect bioelectrical impedance analysis?
Hyophydration: Could lower % of body fat estimate
Hyperhydration: Estimates higher body fat %
Describe the reliability of BIA?
Safe, relatively easy, reliable, noninvasive
What is magnetic resonance imaging (MRI)?
Assesses changes in a muscle’s lean and fat components for multiple purposes.
What can MRIs quantify?
Total and subcutaneous adipose tissue.
What is dual-energy x-ray absorptiometry (DXA)?
Reliably and accurately quantifies fat and nonbone regional lean body mass, including the mineral content of the body’s deeper bony structures.
What are the average body fat percentages for men and women?
Men: 12-15%
Women: 25-28%
What is the calculation for goal body weight?
Fat-free body mass/(1.00-desired %fat)
What is the difference between lean body mass and fat-free mass?
Fat-free mass is devoid of all fat
Lean body mass encompasses non-sex specific essential fat
