Physiology Chapter 2: Hypothalamic Hormones
24 Questions
2 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which hormone significantly increases during late pregnancy and delivery?

  • Oxytocin
  • CRH (correct)
  • Somatostatin
  • GHRH

    • Where are GHRH secreting neurons primarily located?

  • Ventromedial nucleus
  • Lateral hypothalamus
  • Arcuate nuclei (correct)
  • Paraventricular nucleus

    • What is the primary function of GHRH?

  • Inhibit GH release
  • Stimulate somatotropes to release GH (correct)
  • Inhibit insulin secretion
  • Increase glucagon levels

    • How many amino acids does GHRH contain?

    <p>44</p> Signup and view all the answers

    What is the half-life of somatostatin?

    <p>2-3 minutes</p> Signup and view all the answers

    Which of the following hormones is NOT inhibited by somatostatin?

    <p>Corticotropin-releasing hormone</p> Signup and view all the answers

    Which family of peptides includes GHRH?

    <p>Secretin family</p> Signup and view all the answers

    Where is the hypothalamus located?

    <p>At the base of the brain in the diencephalon</p> Signup and view all the answers

    What mechanism do hypothalamic hormones commonly use to exert their action?

    <p>Binding to specific receptors on plasma membrane</p> Signup and view all the answers

    What is the primary function of the hypothalamic median eminence?

    <p>Serves as the vascular link between the hypothalamus and the anterior pituitary</p> Signup and view all the answers

    Which part of the pituitary is known as the adenohypophysis?

    <p>Anterior pituitary</p> Signup and view all the answers

    What type of hormones are primarily regulated by the hypothalamus?

    <p>Anterior pituitary trophic hormones</p> Signup and view all the answers

    What is the average weight of the pituitary gland?

    <p>0.5 g</p> Signup and view all the answers

    During which biological conditions does the pituitary gland weigh double?

    <p>Puberty or pregnancy</p> Signup and view all the answers

    What type of circulation connects the median eminence of the hypothalamus and the anterior pituitary?

    <p>Hypothalamo-pituitary portal system</p> Signup and view all the answers

    Which primary functions are regulated by the hypothalamus?

    <p>Breathing depth and rate, and digestive tract motility</p> Signup and view all the answers

    What is the primary inhibitory hormone for prolactin secretion?

    <p>Dopamine</p> Signup and view all the answers

    Where are the TRH-secreting neurons primarily located?

    <p>Paraventricular nuclei</p> Signup and view all the answers

    Which of the following hormones stimulates the release of LH and FSH?

    <p>Gonadotropin releasing hormone</p> Signup and view all the answers

    What is the half-life of Gonadotropin releasing hormone?

    <p>2-4 minutes</p> Signup and view all the answers

    From which part of the developing anatomy does the anterior pituitary arise?

    <p>Primitive oral cavity</p> Signup and view all the answers

    Which part of the hypothalamus is associated with CRH secretion?

    <p>Anterior portion of the paraventricular nuclei</p> Signup and view all the answers

    What is the role of oxytocin concerning ACTH secretion?

    <p>Inhibits ACTH secretion</p> Signup and view all the answers

    Which characteristic applies to the arcuate nucleus?

    <p>It forms a functional entity with the median eminence.</p> Signup and view all the answers

    Study Notes

    Hypothalamic Hormones and Their Functions

    • Hypothalamic hormones regulate anterior pituitary trophic hormones, which determine target gland secretion.
    • The hypothalamus is located at the base of the brain in the diencephalon, housing neurons critical for hormone regulation.
    • The hypothalamic median eminence forms the vascular link between the hypothalamus and the anterior pituitary gland.

    The Pituitary Gland

    • The pituitary gland, referred to as the "master gland," resides in the sella turcica of the sphenoid bone and weighs approximately 0.5 g.
    • Its weight can double during puberty or pregnancy.
    • The pituitary is divided into two parts:
      • Adenohypophysis (anterior pituitary) - accounts for 75% of gland weight.
      • Neurohypophysis (posterior pituitary) - originates from the brain as an outgrowth from the hypothalamus.

    Vascular Connection

    • The hypothalamic-hypophysial portal system links the hypothalamus to the anterior pituitary, facilitating the transport of hormones.
    • The anterior pituitary is the most vascularized tissue in mammals, receiving 0.8 ml/g/min from arterial blood supplied via internal carotid arteries.

    Hypothalamic Hormones Regulating the Anterior Pituitary

    • Thyrotropin Releasing Hormone (TRH):

      • A tripeptide composed of glutamic acid, histidine, and proline, with a structure of 242 amino acids.
      • Stimulates the release of Thyroid Stimulating Hormone (TSH).
      • Located in the medial portions of the paraventricular nuclei, with a half-life of 6 minutes.

    • Gonadotropin Releasing Hormone (GnRH):

      • A linear decapeptide that stimulates LH and FSH secretion, dependent on its pulse frequency.
      • Secreting neurons reside in the preoptic area of the anterior hypothalamus, with a half-life of 2-4 minutes.

    • Dopamine:

      • Produced in the arcuate nuclei, acting as the primary inhibitor of prolactin release (PRL).
      • Has a half-life of 1-2 minutes.

    • Corticotropin Releasing Hormone (CRH):

      • A 41-amino acid peptide that undergoes extensive synthesis, increasing during late pregnancy and delivery.
      • Regulates ACTH secretion, with neurons located in the paraventricular nuclei.

    • Growth Hormone Releasing Hormone (GHRH):

      • A peptide hormone comprising 108 amino acids, stimulating GH release from somatotrophs in the anterior pituitary.
      • Contains a major isoform of 44 amino acids and has a half-life of 3-7 minutes.

    Other Hormones and Their Actions

    • Somatostatin:
      • A tetradecapeptide with 14 amino acids, inhibits multiple hormones including GH, TSH, insulin, and glucagon.
      • Found in delta cells of pancreatic islets, with a half-life of 2-3 minutes.

    Mechanism of Action

    • Hypothalamic hormones bind to specific plasma membrane receptors on target cells, triggering intracellular signaling pathways.
    • They activate phosphatidylinositol metabolism and the adenylate cyclase system, elevating intracellular calcium levels.
    • The actions of hypothalamic hormones are regulated by various negative-feedback systems to maintain homeostasis.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Chapter 2 Hypothalamic Hormones.docx

    Description

    Explore the critical role of hypothalamic hormones in regulating the secretion of anterior pituitary trophic hormones in this quiz. Understand how these hormones influence target gland activity and the intricate connections between the hypothalamus and the pituitary gland. Test your knowledge on this essential topic in physiology!

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser