Question

a. explain how blood pressure influences the glomerular filtration rate

b.demonstrate how juxtaglomerular feedback will alter the flow of blood and production of filtrate

Answer 1

Answer a). Blood pressure influences the glomerular filteration rate as following.

1. when body blood pressure decreases there is less amount of blood is reaching the kidneys, low blood cause less blood travel through the affarent aretiole to glomerulus and reduces the GFR.
2. when body blood pressure increases the ammount of blood reaching the kidneys is increased and there is sufficient amount of pressure is there to filter the blood through glomerulus. more blood causes more boold filteration and hence GFR increases.

answer b). The JGA plays a complex regulatory role. A fall in glomerular blood flow/glomerular blood pressure/GFR can activate the JG cells to release renin which converts angiotensinogen in blood to angiotensin I and further to angiotensin II. Angiotensin II, being a powerful vasoconstrictor, increases the glomerular blood pressure and thereby GFR. Angiotensin II also activates the adrenal cortex to release Aldosterone. Aldosterone causes reabsorption of Na+ and water from the distal parts of the tubule. This also leads to an increase in blood pressure and GFR. This complex mechanism is generally known as the Renin-Angiotensin mechanism.