AP Biology Questions on Posterior Pituitary Hormones

📚 Quick Study Guide

• 🧠 The posterior pituitary gland, unlike the anterior pituitary, does not synthesize hormones. Instead, it stores and secretes hormones produced by the hypothalamus.
• 💧 The two main hormones released by the posterior pituitary are:
  • Vasopressin (ADH): Regulates water reabsorption in the kidneys.
  • Oxytocin: Involved in uterine contractions during childbirth and milk ejection during lactation.
• 🌊 Vasopressin (ADH) Mechanism:
  • Released in response to dehydration or increased blood osmolarity.
  • Acts on the kidneys to increase water reabsorption, reducing urine volume and concentrating the urine.
• 🤱 Oxytocin Mechanism:
  • Stimulates uterine contractions during labor.
  • Stimulates milk ejection (let-down reflex) in response to suckling.
  • Also involved in social bonding and trust.
• ⚖️ Regulation: Hormone release is controlled by neural signals from the hypothalamus.

🧪 Practice Quiz

1. Which of the following hormones is released by the posterior pituitary?
   1. A. Follicle-stimulating hormone (FSH)
   2. B. Luteinizing hormone (LH)
   3. C. Antidiuretic hormone (ADH)
   4. D. Growth hormone (GH)
2. What is the primary function of vasopressin (ADH)?
   1. A. To stimulate uterine contractions
   2. B. To regulate water reabsorption in the kidneys
   3. C. To stimulate milk ejection
   4. D. To regulate blood glucose levels
3. Where are the hormones released by the posterior pituitary produced?
   1. A. The anterior pituitary
   2. B. The posterior pituitary
   3. C. The adrenal glands
   4. D. The hypothalamus
4. Which of the following stimulates the release of oxytocin?
   1. A. Decreased blood osmolarity
   2. B. Increased blood pressure
   3. C. Suckling
   4. D. Increased blood glucose
5. What is the primary target tissue of vasopressin (ADH)?
   1. A. The uterus
   2. B. The mammary glands
   3. C. The kidneys
   4. D. The liver
6. Which of the following is NOT a function of oxytocin?
   1. A. Stimulating uterine contractions
   2. B. Stimulating milk ejection
   3. C. Promoting social bonding
   4. D. Increasing blood glucose levels
7. What condition might result from a deficiency in vasopressin (ADH) secretion?
   1. A. Diabetes mellitus
   2. B. Diabetes insipidus
   3. C. Cushing's syndrome
   4. D. Addison's disease