Kidney Flashcards
Describe the first part of filtration, which happens in a ____
Nephron, blood moves into kidney from renal artery into the glomerulus (ball of capillaries), this forces ions , glucose, amino acids into the Bowman’s capsule, a surrounding collecting duct
Describe path of filtration post glomerulus
fluid moves through proximal convoluted tubule into renal cortex, where most solutes are re-absorbed via simple osmosis and diffusion
what two structures make up the loop of Henle
Ascending and descending, into the renal medulla
Fluid enters loop of Henle through ___ limb, into ___ Na+ conc, which causes __
Descending, into high Na+ so it looses more and more water
The second part of the loop of Henle, the fluid (with a ___ conc), moves up the ___ limb, where ____
high Na+ conc. (lost water in descending limb), ascending, Na+ in high conc. inside the ascending limb diffuses out, then is actively pumped out at the top - causing the high external Na+ in the first place
The name of exchange in the loop of Henle
Counter-current exchange
What hormone controls the final conc. of urine in the collecting duct, and where is it secreted
Antidiuretic Hormone (ADH), secreted in the posterior pituitary gland
What does ADH do
Anti-diuretic, ant-urine, helps to increase reabsorption to retain more water, raise the blood pressure
How does ADH work
increase’s the nephron’s permeability to water to allow more water to be reabsorbed
what condition can cause symptoms similar to another because it blocks ADH secretion?
Diabetes insipidus > tumour/injury to pituitary, no ADH means less water reabsorbed, more frequent urination, presents like diabetes
What begins the renin-angiotensin system
JGA (juxta-glomerular apparatus), cluster of cells around glomerulus that release renin if BP drops
Describe the renin-angiotensin pathway up to AT2
Renin converts angiotensinogen to angiotensin 1
ACE catalyses angiotensin 1 > angiotensin 2
What does the renin-angiotensin system do?
increases blood pressure through reabsorption and vasoconstriction
How does angiotensin 2 work
Stimulates adrenal gland to produce aldosterone, which acts on kidneys to reabsorb Na+ and lose K+
Direct act on vessel to vasoconstrict
Signs of kidney dysfunction
Changes in urine, dark urine, proteinuria (proteins in urine), Haematuria (blood in urine), fluid retention, sodium/potassium imbalance
