The hormones are responsible for regulating the internal body temperature. A feedback mechanism tends to accelerate or inhibit the hormonal secretion. This loop is usually the negative feedback mechanism among most of the hormones.
Negative Feedback Mechanism
- It occurs when the original effect of the stimulus is reduced by the output.
- Negative feedback mechanism normalizes the things when they start becoming too extreme. For eg., the thyroid gland is regulated by a negative feedback mechanism.
- The hormone secreted by the hypothalamus stimulates the pituitary gland to release thyroid stimulating hormone.
- In turn, the thyroid stimulating hormone triggers the thyroid gland to release its hormones.
- When the thyroid level increases, the hormones stop the secretion of TRH by the hypothalamus and secretion of TSH by the pituitary gland by the feedback mechanism.
- The secretion of hormones by the thyroid gland is inhibited without the stimulation of TSH.
- The thyroid hormone levels fall very low.
- The insulin secretion by the pancreas is also controlled by the negative feedback mechanism.
Also read: Hormones
Positive Feedback Mechanism
- It occurs when the original effect of the stimulus is enhanced by the output.
- The conditions become extreme in this mechanism.
- Milk secreted by a mother’s mammary glands is one of the examples of positive feedback mechanism.
- While suckling, the nerve sends signals from the nipple to stimulate the pituitary gland to secrete prolactin.
- In turn, prolactin triggers the mammary glands to secrete milk.
- As the baby suckles more milk, more prolactin is secreted and more milk is produced.
Further Reading: Thyroid Gland