Antidiuretic hormone

Examples of Antidiuretic hormone in the following topics:

• The Posterior Pituitary

  • The posterior pituitary secretes two important endocrine hormones—oxytocin and antidiuretic hormone.
  • These axons release peptide hormones into the capillaries of the hypophyseal circulation.
  • Oxytocin is one of the few hormones that create a positive feedback loop.
  • Antidiuretic hormone (ADH, also known as vasopressin), the majority of which is released from the supraoptic nucleus in the hypothalamus.
  • Identify the location of the posterior pituitary and the hormones associated with it

• Regulation of Urine Concentration and Volume

  • Antidiuretic hormone (ADH), produced by the pituitary gland, controls the amount of water that is reabsorbed through the collecting ducts.
  • There are a few complex systems involved in regulating blood volume and urine production, such as the intricate renin-angiotensin system, and the simpler anti-diuretic hormone (ADH) feedback system.
  • ADH is a hormone secreted from the posterior pituitary gland in response to increased plasma osmolarity (ie. increased ion concentration in the blood), which is generally due to increased concentration of ions relative to volume of plasma, or decreased plasma volume.
  • Describe how regulating the amount of water excreted in urine is an essential component of homeostasis that is regulated by the antidiuretic hormone (ADH)

• Circumventricular Organs

  • As a result, neurons located in circumventricular organs can directly sense the concentrations of various compounds, particularly peptide hormones, in the bloodstream without the need for specialized transport systems that move those compounds across the blood-brain barrier.
  • These organs secrete or are sites of action of a variety of different hormones, neurotransmitters, and cytokines.
  • The secretory organs are responsible for secreting hormones and glycoproteins into the peripheral vascular system using feedback from both the brain environment and external stimuli.
  • Posterior pituitary: Stores and releases oxytocin and vasopressin, also known as antidiuretic hormone, produced in the hypothalamus.

• Lipid-Derived, Amino Acid-Derived, and Peptide Hormones

  • All hormones in the human body can be divided into lipid-derived, amino acid-derived, and peptide hormones.
  • The primary class of lipid hormones in humans is the steroid hormones.
  • Examples of steroid hormones include estradiol, which is an estrogen, or female sex hormone, and testosterone, which is an androgen, or male sex hormone.
  • The peptide hormones include molecules that are short polypeptide chains, such as antidiuretic hormone and oxytocin produced in the brain and released into the blood in the posterior pituitary gland.
  • The structures of peptide hormones (a) oxytocin, (b) growth hormone, and (c) follicle-stimulating hormone are shown.

• Hormonal Regulation of the Excretory System

  • The anterior pituitary is composed of glandular cells that secrete protein hormones.
  • The hypothalamus produces a polypeptide hormone known as antidiuretic hormone (ADH), which is transported to and released from the posterior pituitary gland.
  • Another hormone responsible for maintaining electrolyte concentrations in extracellular fluids is aldosterone, a steroid hormone that is produced by the adrenal cortex.
  • Angiotensin II stimulates release of these hormones.
  • Explain how the actions of different hormones regulate the excretory system

• Production of Dilute and Concentrated Urine

  • The hormones ADH (Anti-diuretic Hormone, also known as vasopressin) and Aldosterone play a major role in this balance.
  • These areas project to the supraoptic nucleus and paraventricular nucleus, which contain neurons that secrete the antidiuretic hormone, vasopressin, from their nerve endings in the posterior pituitary.
  • Thus, there will be an increase in the secretion of antidiuretic hormone, causing fluid to be retained by the kidneys and urine output to be reduced.
  • The system then stimulates zona glomerulosa of the adrenal cortex which, in turn, secretes the hormone aldosterone.
  • This hormone stimulates the reabsorption of sodium ions from distal tubules and collecting ducts.

• Other Hormonal Controls for Osmoregulation

  • The renin-angiotensin-aldosterone system (RAAS) is a hormone system that regulates blood pressure and water (fluid) balance .
  • Mineralocorticoids are hormones synthesized by the adrenal cortex that affect osmotic balance.
  • Antidiuretic hormone or ADH (also called vasopressin) helps the body conserve water when body fluid volume, especially that of blood, is low.
  • The atrial natriuretic peptide (ANP) hormone lowers blood pressure by acting as a vasodilator (dilating or widening blood vessels).
  • The hormone ANP has antagonistic effects.

• Hypothalamic-Pituitary Axis

  • The anterior pituitary produces seven hormones: growth hormone (GH), prolactin (PRL), thyroid-stimulating hormone (TSH), melanin-stimulating hormone (MSH), adrenocorticotropic hormone (ACTH), follicle-stimulating hormone (FSH), and luteinizing hormone (LH).
  • Anterior pituitary hormones are sometimes referred to as tropic hormones because they control the functioning of other organs.
  • These regulatory hormones can be releasing hormones or inhibiting hormones, causing more or less of the anterior pituitary hormones to be secreted.
  • Negative feedback then regulates how much of these regulatory hormones are released and how much anterior pituitary hormone is secreted.
  • The antidiuretic hormone (ADH) (or vasopressin) and oxytocin are produced by neurons in the hypothalamus and transported within these axons along the infundibulum to the posterior pituitary.

• Overview of Endocrine Glands

  • Two hormones—oxytocin and antidiuretic hormone (ADH)—are produced and released this way.
  • The anterior pituitary is involved in sending hormones that control all other hormones of the body.
  • Communication between the hypothalamus and the anterior pituitary occurs through hormones (releasing hormones and inhibiting hormones) that are produced by the hypothalamus and delivered to the anterior pituitary via a portal network of capillaries.
  • The hormones then diffuse from this secondary plexus into the anterior pituitary, where they initiate the production of specific hormones by the anterior pituitary.
  • These hormones increase the metabolic activity of the body‘s cells.

• Nephron, Parts, and Histology

  • It is regulated by the neuroendocrine system by hormones such as antidiuretic hormone, aldosterone, and parathyroid hormone.
  • Unlike the other components of the nephron, its permeability to water is variable depending on hormone stimulus, enabling complex regulation of blood osmolarity, volume, pressure, and pH.
  • Many other hormones will induce other important changes in the distal convoluted tubule that fulfill the other homeostatic functions of the kidney.
  • The collecting duct is similar in function to the distal convoluted tubule and generally responds the same way to the same hormone stimuli.
  • The osmolarity of fluid through the distal tubule and collecting duct is highly variable depending on hormone stimulus.