The main body system in control of Lisa's response to stimuli is the nervous system. Acting as the control center, the brain works with the circulatory system and integumentary system to elicit the normal response to embarrassment.
Acts of stress activate the sympathetic nervous system in Lisa's brain, which prepares the body's fight-or-flight response. An effect of the sympathetic nerves acting on her heart is the increase of her heart neat rate.
One of the integumentary system's functions is to regulate body temperature, which is seen increasing as Lisa begins sweating. The autonomic nervous system regulates peripheral flow and sweat glands which is evident when the blood rushes to Lisa's face as she reddens from embarrassment and she starts sweating.