Overview
This lecture covers the mechanisms by which hormones interact, the types of hormone interactions, and the physiological outcomes from these interactions.
Types of Hormone Interactions
- Hormones can interact in three main ways: permissiveness, synergism, and antagonism.
- Permissiveness occurs when one hormone enables another to act.
- Synergism happens when two hormones together produce a greater effect than each alone.
- Antagonism is when one hormone opposes the action of another.
Permissiveness
- A permissive hormone must be present for another hormone to have its full effect.
- Example: Thyroid hormone increases the number of receptors for epinephrine, enhancing its effect.
Synergism
- Synergistic hormones amplify each other’s effects, leading to a combined response greater than the sum of individual actions.
- Example: Glucagon and epinephrine both raise blood glucose, but together cause an even greater increase.
Antagonism
- Antagonistic hormones reduce or block the effects of each other.
- Example: Insulin lowers blood glucose, while glucagon raises it; their actions are antagonistic.
Physiological Outcomes of Hormone Interactions
- Hormone interactions ensure balanced physiological processes and precise regulation of body functions.
- Disruption in hormone interaction can lead to disease or hormonal imbalances.
Key Terms & Definitions
- Permissiveness — One hormone is required for another to exert its effects.
- Synergism — Two hormones produce a combined effect greater than the sum of their individual effects.
- Antagonism — One hormone opposes the action of another.
Action Items / Next Steps
- Review textbook sections on hormone interactions.
- Complete practice questions on hormone relationships for next class.