Question

Human Physiology

Describe the effect aldosterone and ANP have on sodium levels in the blood.

Answer 1

The effect of aldosterone - Aldosterone is the main mineralocorticoids. Its functions are associated with the maintenance of the electrolyte balance in the body It stimulates gthe reabsorption of sodium by the renal tubules and when the amount od sodium reabsorbed is incresed the amount of potassium excreated is increased. Indirectly this affects water excretion as water and electrolyte excretion are related. The amount of aldosterone produced is influenced by the sodium level in the blood. If there is a fall in the sodium blood level, more aldosterone is secreated and more sodium reabsorbed. Renin angiotensis aldosterone system. when renal blood flow is reduced the enzyme renin is secreted by kidney cells. This promotes the conversion of angiotenisinogen, produced by the liver, to angiotensin which stimulates the production of aldosterone by the adrenal cortex. Aldosterone increases the reabsorption of sodium and water and the excretion of potassium by the kidneys. This raises ythe blood volume and the flow of blood through the kidneys, suppressing renin production and reducing aldosterone secretion.

Effect of ANP on sodium levels in the blood

Fluid volume and blood pressure are closely related, fluid volume affects blood vloume that effects blood pressure. Heart secretes a hormone to help regulate blood pressure. Artrial natriuretic peptide (ANP) is in released by the artria of the heart. ANP is secreted in response to an increase in blood volume. ANP decrease s sodium reabsorption in the kidneys. this means more sodiun exite the body. Water follows which reduces fluid volume blood volume blood pressure. ANP promotes vasodilation in blood vessels. ANP increases glomerular filteration by vasodialting the afferent areteriole in the nephron. This increases the amount of water and sodium excreted by the kidneys which have the lower blood pressure. Its inhibits renin angiotensin system, releases free fatty acids from adipose tissue.