Final answer:
The fight-or-flight response is a set of physiological changes that prepare the body to confront or escape from danger, including increased heart rate, dilation of bronchi, pupil dilation, and release of adrenaline and cortisol.
Step-by-step explanation:
Physiological Changes During the Fight-or-Flight Response
When an individual is faced with a threat, the body undergoes various physiological changes known as the fight-or-flight response. This response is an evolutionary adaptation that prepares an individual to confront or escape from danger. The autonomic nervous system, specifically the sympathetic division, activates this response, leading to several physiological effects:
- Increase in heart rate to pump more blood, enhancing oxygen delivery to muscles.
- Dilation of the bronchi in the lungs, facilitating increased air exchange and oxygen intake.
- Release of glucose to provide immediate energy for muscle activity.
- Elevation of blood pressure and dilation of blood vessels in skeletal muscles, improving nutrient delivery and waste removal.
- Pupil dilation enhances visual sensitivity and peripheral vision.
- Activation of sweat glands to help regulate body temperature during exertion.
- Suppression of non-essential body functions like digestion and reproductive activities to prioritize survival.
Critical hormones such as adrenaline (epinephrine) and norepinephrine (noradrenaline) are released, leading to these changes. Additionally, the endocrine system plays a role in augmenting the sympathetic response, primarily through the release of hormones from the adrenal glands like cortisol which helps to manage stress and to modulate metabolism. Thus, the fight-or-flight response equips the body with heightened sensory and physical capacities to either fight the threat or flee to safety.