Stress hormones tend to increase the metabolic needs of the body because they tend to have a toll on the amount of biochemical reactions which are going on. For that reason, having a stress response will increase the amounts of calories; energy in effect, that need to be consumed.
Because swinging your head around risks injury in your neck and swinging your arms could cause damage to your shoulders.
Placenta membrane is used to separate the embryonic blood from maternal blood. Through this membrane, exchanges between the embryonic blood and maternal blood takes place.
The readings will generally be quite low. :)
