Vasopressin Flashcards
also known as vasopressin, argipressin or antidiuretic hormone (ADH)
Arginine vasopressin (AVP)
Vasopressin is a peptide hormone. It is derived from a ________________ precursor that is synthesized in the hypothalamus and stored in vesicles at the posterior pituitary. Most of it is stored in the posterior pituitary to be released into the blood stream; however, some of it is also released directly into the brain.
preprohormone
It is a nonapeptide that acts on the DCT and collecting tubule of the nephron
It decreases the production of urine by promoting the reabsorption of water by the renal tubules (maintains water homeostasis)
Osmolality of blood is the principal regulator of ADH secretion
A decreased in blood volume or blood pressure will stimulate ADH release
Vasopressin
It is a potent pressor agent and affects blood clotting by promoting Factor ___ release from the
hepatocytes and _____release from the endothelium
VII; vWF
One of the most important roles of AVP is to regulate the body’s retention of _____; it is released
when the body is dehydrated and causes the kidneys to conserve water, thus concentrating the urine, and reducing urine volume.
In high concentrations, it also raises blood pressure by inducing moderate __________________.
water; vasoconstriction
It increases the permeability to water of the distal convoluted tubules and collecting tubules in the
nephrons of kidneys and thus allows water reabsorption and excretion of a smaller volume of concentrated urine - __________.
antidiuresis
ADH’s second effect on the kidney is to increase the permeability of the __________portion of the collecting duct to urea, allowing increased reabsorption of urea into the medullary interstitium, down the concentration gradient created from the removal of water in the cortical collecting duct.
papillary
The third effect that AVP has on the kidney is that it stimulates sodium reabsorption in the thick ascending loop of _______by increasing the activity of the Na+-K+-2Cl–cotransporter.
Henle
Vasopressin increases peripheral vascular resistance and thus increases _________ blood pressure. This effect appears small in healthy individuals; however it becomes an important compensatory mechanism for restoring blood pressure in ____________shock such as occurs during hemorrhage.
arterial; hypovolemic
It has been implicated in memory formation, including delayed _______________________________ though the mechanism remains unknown, and these findings are controversial.
reflexes, image, short- and long-term memory,
Vasopressin released from centrally-projecting hypothalamic neurons is involved in
aggression, blood pressure regulation and temperature regulation
Vasopressin is secreted from the posterior pituitary gland in response to reductions in plasma volume, in response to increases in the plasma osmolality, and in response to _____________ by the small intestine
cholecystokinin
activated by pressure receptors in the veins, atria, and carotids.
Secretion in response to reduced plasma volume
mediated by osmoreceptors in the hypothalamus
Secretion in response to increases in plasma osmotic pressure
mediated by an unknown pathway
Secretion in response to increases in plasma Cholecystokinin
