Feedback Mechanism (F)

Definition of Feedback Loops:
- Biological processes that maintain homeostasis or body balance.
- They can be categorized into two types: positive feedback and negative feedback.

Function:
- Intensifies a response in a biological system.
Estrogen Production and Positive Feedback Mechanism:
- When the ovary produces estrogen, it stimulates the hypothalamus to produce Gonadotropin-Releasing Hormone (GnRH), as well as Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH) from the anterior pituitary gland.
- The presence of estrogen thus promotes the production of these hormones, illustrating a positive feedback mechanism.
- Substances that promote hormone production are categorized as stimulatory substances.

Function:
- Reduces the effect of a stimulus in a biological system.
Progesterone Production and Negative Feedback Mechanism:
- An increase in LH levels within the bloodstream triggers the production of progesterone.
- Subsequently, progesterone exerts an inhibitory effect on the production of GnRH and LH.
- This demonstrates a negative feedback mechanism, as it decreases or stops further hormone production.
- Substances that reduce or halt hormone production are referred to as inhibitory substances.

Childbirth:
- The stretching of uterine walls causes contractions that further stretch the walls, continuing until birthing occurs.
- Type of Feedback: Positive (+)
Lactation:
- Suckling stimulates milk production, which causes further feeding, continuing until the baby stops feeding.
- Type of Feedback: Positive (+)
Menstruation:
- Follicles become the corpus luteum, producing estrogen and progesterone which inhibit FSH and LH secretion by the pituitary gland.
- Type of Feedback: Negative (-)
Ovulation:
- The dominant follicle releases estrogen, which stimulates the release of LH and FSH to promote further follicular growth.
- Type of Feedback: Positive (+)