4 ADH, OT, PRL

Homeostasis: Maintenance of a stable internal environment.
Mechanisms:
- Negative feedback: Results opposite the initial stimulus (e.g., cooling down when hot).
- Positive feedback: Result intensifies the initial stimulus.

Normal blood glucose range: 77 to 110 mg/dL.
Key hormones:
- Insulin: Decreases blood glucose by allowing glucose into cells; produced by the islets of Langerhans in the pancreas.
- Glucagon: Increases blood glucose through glycogen breakdown (glycogenolysis).

Type 1 Diabetes: Body does not produce enough insulin due to beta cell dysfunction. Results in high blood glucose due to inability to transport glucose into cells.
Type 2 Diabetes: Typically develops later in life; involves insulin resistance. Cells do not respond effectively to insulin, leading to high blood glucose.

Location: Hypothalamus is above the pituitary; the pituitary gland (anterior and posterior parts) regulates other glands.
ADH (Antidiuretic Hormone): Causes water retention, increases fluid volume during dehydration.
- Stimulus for release: Low fluid volume detected by the hypothalamus.
- Function: Acts on kidneys to decrease urine output, preserving water.
OT (Oxytocin): Involved in childbirth and lactation.
- Stimulus: Labor contractions or suckling detected by the hypothalamus.
- Function: Increases contractions in labor and milk ejection during breastfeeding.

Uterine contractions during childbirth detected by hypothalamus leading to more OT until birth occurs.
Milk ejection during breastfeeding driven by suckling, also leading to more OT release.
Blood Clotting: Example of positive feedback involving the production of blood clots.

Produced by the anterior pituitary; promotes milk production in conjunction with estrogen.