Answer to Question 1
Whenever we confront a crisis, large or small, our bodies produce powerful hormones that provide
extra energy. However, this stress response dampens immunity, reducing the number of some key
immune cells and the responsiveness of others. Stress affects the body's immune system in different ways, depending on two factors: the controllability or uncontrollability of the stressor and the mental effort required to cope with the stress.
An uncontrollable stressor that lasts longer than 15 minutes may interfere with cytokine interleukin-
6, which plays an essential role in activating the immune defenses. Uncontrollable stressors also produce high levels of the hormone cortisol, which suppresses immune system functioning. The mental efforts required to cope with high-level stressors produce only brief immune changes that appear to have little consequence for health. However, stress has been shown to slow pro-inflammatory cytokine production, which is essential for healing.
Answer to Question 2
purging
An example of a two-component regulatory system in bacteria
Tattoos and Body Piercings: This patient developed cellulitis from tattoo ink
The male reproductive system.
Lymphatic system.
Body Cavities
Respiratory system of a bird.