Question

Short / Long answer type questions.
What is feedback control? Illustrate feedback mechanism of homeostasis by an example of hormones.

Answer 1

• The endocrine glands secrete hormones depending upon the need of the organism. The number of hormones secreted should be accurate. The regulation of the quantity of the hormones and the timing of its release are controlled by feedback mechanisms.
  
• There are two types of feedback mechanisms - positive and negative feedback.
  

1. Positive feedback: In this mechanism, the response accelerates after the feedback. The effect is further intensified in the same direction. It helps in speeding up the process occurring in various body systems. It is the opposite of negative feedback.

2. Negative feedback: In this mechanism, the information given by the feedback causes a reverse response. It occurs when the system needs to slow down or completely stop a process.

• For example Childbirth
  

Uterine contractions occur during the onset of labour pain. These contractions stimulate the release of a specific hormone called oxytocin (from the pituitary gland), which intensifies the contractions. The contractions further stimulate the production of oxytocin and this cycle stops only after the birth of the baby. This is an example of positive feedback.