Long Term Control of Blood Pressure Flashcards
What are the three hormone systems used to control blood pressure long term?
Renin-angiotensin-aldosterone system Antidiuretic factor (vasopressin) Atrial and brain natriuretic peptide
What are the function of the kidneys?
Excretion of waste Ion balance pH Osmolarity Plasma volume
What determines how big the osmotic gradient is in the collecting duct?
The control over Na+ transport
What happens to urine when the collecting duct is very impermeable to water?
Little reabsorption, lots of urine (diuresis) and reduction of plasma volume
What happens to ruin when the collecting duct in very permeable to water?
High water reabsorption, little urine (hyperosmotic) and increased in plasma volume
Where is renin produced?
Juxtaglomerular (granule cells) of the kidney
What stimulates the production of renin?
Sympathetic innervation of the Jux.
Decrease in distention of afferent arterioles
Decreased delivery of Na+ and Cl-
What is the function of renin?
Converts inactive angiotensinogen to angiotensin I (which is then converts to Ang. II by ACE)
What is the action of angiotensin II?
Stimulates release of aldosterone from adrenal cortex (Increase Na reabsorption in Loop of Henle - increases blood voume)
Increase ADH from pituitary (increase water permeability of collecting duct -> high blood vol.)
Vasoconstriction (increase TPR)
How is the Renin-Angiotensin-Aldosterone system a negative feedback system?
Detect decrease in MAP and stimulates response to release renin which increase MAP
What triggers the release of Anti-Diuretic Hormone?
Decrease in plasma volume (detected by cardiopulmonary baroreceptors)
Increasing in ISF osmolarity
Circulating angiotensin II
Where is ADH produced?
Synthesised in the hypothalamus and released from the posterior pituitary
What is the action of ADH?
Increases permeability of collecting duct to water; reduced diuresis and increases plasma volume
Vasoconstriction -> increase MAP
How is the ADH a negative feedback system?
Decrease in MAP, stimulate release of ADH to increase MAP
Where is the atrial and bran natriuretic peptide produced?
ANP - Myocardial cells in the atria
BNP - myocardial cells in the ventricles
