key term - Epinephrine

Definition

Epinephrine, also known as adrenaline, is a hormone and neurotransmitter produced by the adrenal glands. It plays a crucial role in the body's fight-or-flight response by preparing the body for quick action during stressful situations. This includes increasing heart rate, dilating airways, and mobilizing energy stores, which are essential for immediate physical responses.

5 Must Know Facts For Your Next Test

1. Epinephrine is released into the bloodstream during stressful situations, leading to rapid changes in the body to enhance physical performance.
2. It stimulates glycogen breakdown in the liver and muscle tissues, providing a quick source of glucose for energy.
3. The hormone also increases blood flow to muscles while decreasing blood flow to non-essential systems like digestion during emergencies.
4. Epinephrine's effects can be rapidly reversed by its antagonist, propranolol, which is used to treat conditions like hypertension.
5. In medical settings, epinephrine is used in emergency situations such as anaphylaxis and cardiac arrest to quickly restore vital signs.

Review Questions

• How does epinephrine contribute to the body's fight-or-flight response?
  • Epinephrine enhances the fight-or-flight response by triggering a series of physiological changes that prepare the body for rapid action. It increases heart rate and blood pressure, dilates airways to improve oxygen intake, and mobilizes energy stores by promoting glycogen breakdown. These actions enable the body to respond swiftly and effectively in high-stress situations.
• Discuss how the integration of epinephrine with other hormones regulates metabolism during stress.
  • Epinephrine works alongside other hormones like cortisol and glucagon to regulate metabolism during stress. While epinephrine promotes glycogen breakdown for quick energy, cortisol helps maintain blood glucose levels over a longer period by stimulating gluconeogenesis in the liver. This hormonal interplay ensures that the body has a sufficient energy supply to cope with prolonged stress while maintaining overall metabolic balance.
• Evaluate the impact of epinephrine on both short-term physiological responses and long-term metabolic adaptations under chronic stress conditions.
  • In short-term scenarios, epinephrine rapidly prepares the body for immediate action by increasing heart rate and energy availability. However, under chronic stress conditions where epinephrine is consistently elevated, this can lead to detrimental long-term effects such as insulin resistance, increased risk of cardiovascular diseases, and metabolic dysregulation. The body's prolonged exposure to high levels of epinephrine may disrupt normal homeostasis and contribute to various health issues over time.

Related terms

Catecholamines: A class of hormones that includes epinephrine, norepinephrine, and dopamine, which are involved in the body's stress response and regulation of various physiological processes.

Adrenal Glands: Small glands located on top of each kidney that produce various hormones, including epinephrine and cortisol, which are vital for stress management and metabolism.

Sympathetic Nervous System:

Part of the autonomic nervous system that prepares the body for 'fight or flight' responses by increasing heart rate, dilating pupils, and releasing epinephrine from the adrenal glands.