Lecture Notes on Posterior Pituitary, ADH, Oxytocin, and Pineal Gland

Posterior Pituitary Overview

Focus on two main hormones: Antidiuretic Hormone (ADH) and Oxytocin.
Both hormones are produced by the hypothalamus, transported to the posterior pituitary, and then secreted into the bloodstream.

Function: Reduces urine production by acting as an anti-diuretic.
Importance: Discussed in multiple contexts (cardiovascular and urinary systems) throughout the semester.
Stimulation:
- Triggered by high osmolarity (high solute concentration) which indicates dehydration.
- Produced more when hypothalamus detects dehydration.
Main Targets and Actions:
- Kidneys: Decrease urine production to conserve water.
- Sweat Glands: Reduce perspiration to prevent further dehydration.
- Blood Vessels: Induce vasoconstriction to maintain blood pressure during dehydration.
Conditions:
- Overproduction can lead to water retention.
- Hyposecretion leads to Diabetes Insipidus (excessive urination, thirst, dehydration).

Production and Secretion: Made in the hypothalamus, secreted by the posterior pituitary.
Primary Targets:
- Uterus: Stimulates muscle contractions during childbirth (positive feedback mechanism).
  - Synthetic oxytocin (Pitocin) used to induce labor.
- Mammary Glands: Stimulates milk ejection (letdown), not production.
Additional Effects:
- Involved in social bonding; known as the "love hormone."
- May affect emotional sensitivity and social behaviors.