Renal Physiology Flashcards
Urinary system function
Removal of waste
regulation of water volume, salt and pH
other homeostatic functions
Name functional unit of urinary system
Nephron
Name the 3 steps in the process of nephron
Filtration
absorption
secretion
Afferent arteriole
towards the glomerulus
efferent arteriole
away from glomerulus
5 structures of renal tubular(nephron)
Glomerular(bowman) capsule
Proximal convoluted tubule
loop of henle(thin desc,thin asc, thick asc)
distal convoluted tubule
collecting duct
Which parts of nephron are in which part of the kidney
loop of henele and lower collecting duct is in the medulla and rest is in cortex
the actual loop of the loop of henle is in the inner medulla
Name 2 different types of nephron
cortical nephrons
juxtamedullary mephrons
Features of cortical nephrons and regulation use
Renal corpuscle within cortex
normal conditions
relatively short loop of henle
regulate blood volume
Features of juxta medullary nephrons and regulation use
Renal corpuscle close to medulla
extreme conditions
relatively long loop of henle
retention of water
Draw a renal corpuscle cross section
insert image
reabsorption and secretion for PCT
reabsorb-water ions nutrients
secretion- urea H+, waste
reabsorption and secretion loop of henle
descending limb REABSORPTION of water
ascending limb reabsorption of sodium and other ions
reabsorption and secretion for DCT
reabsorb- ions, water (ADH)
reabsorption/secretion for collecting duct
reabsorb- water(ADH)/urea
secretion-ions
Features of glomerular filtration
blood flow essential for function
regulation of glomerular filtration rate
balance of afferent+efferent vasoconstriction
What is urine output based of
ADH in DCT and CD
composition:
- acid-base homeostasis
-relative proportions of components reabsorbed and excreted
What is the juxtaglomerular apparatus
-DCT runs between afferent and efferent arterioles
-provides feedback on composition of filtrate
-macula densa cells
What are macular densa cells
specialized cells in the tubule wall
What does the RAAS do/maintain
maintenance of blood pressure, blood volume and electrolyte balance
1st step of RAAS
Pressure reduction detected by baroreceptors in JGA(in nephron) and sodium reduction by chemoreceptors in macula densa(in DCT) causes release of renin by JGA(juctaglomerular aparatus)
What does Renin cause (2nd RAAS)
angiotensinogen from liver conversion to angiotensin 1 and then converting enzymes from lungs convert to angiotensin 2
What happens to angiotensin 2 (3rd RAAS)
PCT-increase sodium retention
Posterior pituitary- release ADH(water reabsorption by DCT and CD)
Adrenal gland- increase of aldosterone- kidneys to increase sodium reabsorption(DCT and cause water reabsorption)
What else does angiotensin 2 do to increase blood pressure/volume
Vasoconstriction of arterioles and increase sympathetic nervous system
Increase GFR to aid filtration despite reduction in pressure and volume of blood
How can kidney control pH briefly
adjusting amount of HCO3- excreted or reabsorbed in PCT and DCT and amount of H+ actively secreted by PCT and CD
Reabsorption of HCO3 equal to excretion of free H+
Hours to days for changes to occur
How do kidney help erthrocyte production
production of erythropoietin which helps erythropoiesis through action on bone marrow
When does kidney release erythropoietin
reduction in RBC cause reduction in pO2 which is detected by renal interstitial peritubular cells so releases erythropoietin and RBC made so pO2 restored so erythropoietin levels fall
