The hypothalamus–pituitary complex links the nervous and endocrine systems. This lesson introduces the anatomy of the complex and explains how the posterior pituitary releases hormones made by the hypothalamus.
The hypothalamus is part of the diencephalon, located below and anterior to the thalamus. It has both neural and endocrine functions: it receives information from the nervous system and produces hormones that influence the pituitary and other body functions.
All flashcards
What does the hypophyseal portal system do?
It carries hypothalamic releasing and inhibiting hormones directly to the anterior pituitary through portal blood vessels.
How does the posterior pituitary differ from the anterior pituitary in hormone production?
The posterior pituitary stores and releases hypothalamic hormones; the anterior pituitary synthesizes its own hormones.
How do insulin-like growth factors contribute to growth hormone effects?
They promote cell proliferation, reduce apoptosis, and support amino-acid uptake for protein synthesis.
What stimulates anterior pituitary release of FSH and LH?
Gonadotropin-releasing hormone (GnRH) from the hypothalamus stimulates their release.
How do prolactin and oxytocin differ in lactation?
Prolactin promotes milk production; oxytocin causes milk ejection by contracting cells around milk ducts.
Quiz questions
What is the primary role of the hypophyseal portal system?Answer: It delivers hypothalamic regulatory hormones directly to the anterior pituitary.
What condition can result from excess growth hormone after normal growth has ended?Answer: Acromegaly, with enlargement of bones in the face, hands, and feet.
How do rising thyroid hormone levels regulate the hypothalamic–pituitary–thyroid pathway?Answer: They inhibit secretion of both TRH and TSH through negative feedback.
What does LH stimulate in the testes?Answer: Testosterone production.
Which statement correctly distinguishes prolactin from oxytocin in lactation?Answer: Prolactin promotes milk production, while oxytocin causes milk ejection.
Based on Anatomy and Physiology 2e by J. Gordon Betts, Kelly A. Young, James A. Wise, Eddie Johnson, Brandon Poe, Dean H. Kruse, Oksana Korol, Jody E. Johnson, Mark Womble, Peter DeSaix (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.