Final answer:
The alarm response triggers a cascade of physical reactions including the release of epinephrine and norepinephrine, dilation of pupils, increased heart and breathing rates, sweating, and the redirection of blood flow towards muscles.
Step-by-step explanation:
The physical reactions included in the alarm response are part of the first stage of the General Adaptation Syndrome (GAS). When faced with a stressor, the body triggers a series of physiological changes to prepare for the fight-or-flight response. During an alarm reaction, the following occurs:
- Release of epinephrine (adrenaline) and norepinephrine (noradrenaline) from the adrenal glands, which leads to a series of bodily changes.
- Dilation of pupils for better vision.
- Increased heart rate and blood pressure to ensure more blood is delivered to muscles.
- Increased breathing rate and bronchial dilation for enhanced air exchange.
- Activation of sweat glands.
- Redirection of blood flow away from non-essential functions (like digestion) towards skeletal muscles.
Together, these reactions enable the organism to either run away from a threat or confront it. The alarm response also involves the activation of the sympathetic nervous system and the endocrine system to aid in rapid bodily arousal, preparing the person to cope with the perceived threat.