Positive Feedback Mechanism

Introduction

• Focus on the positive feedback mechanism.
• Positive feedback is the opposite of the negative feedback mechanism.
• Less common in the body compared to negative feedback.
• Occurs during normal childbirth and blood clotting.

What is Positive Feedback?

• Increases the original stimulus.
• Reinforces and strengthens changes that cause homeostatic imbalance.

Examples:

Childbirth

1. Contraction of Uterine Wall
   • Forces baby into cervix.
   • Creates an internal stimulus by increasing cervix stretching.
   • Causes homeostatic imbalance.
2. Detection and Response
   • Stretch-sensitive receptors in the cervix detect change.
   • Send nerve impulses to the brain.
   • Brain releases oxytocin into the blood.
3. Effect of Oxytocin
   • Increases contraction of uterine muscles.
   • Further stretches cervix.
   • Continues until childbirth is complete.
4. Breaking the Cycle
   • Stretching decreases after childbirth.
   • Positive feedback loop breaks.
   • Returns to homeostasis.

Why is it Positive Feedback?

• Increased cervix stretching (stimulus) leads to oxytocin release.
• Oxytocin release further increases cervix stretching.
• Strengthens the initial stimulus resulting in a feedback loop.

Conclusion

• Comprehension of both feedback mechanisms is essential.
• Positive feedback is vital in specific physiological processes like childbirth.

Note: For further understanding, it is advised to compare this with the negative feedback mechanism. Any questions can be directed to the comments section for clarification.