10.1 Renal system Flashcards
Vasa recta vs peritubular capillaries
capillary for O2, runs parallel to loop of Henle vs capillary for nutrients, collects solutes from renal tubules to blood, runs around PCT and DCT
What is in the renal hilum? What’s in the renal corpuscle?
Renal artery, renal vein, ureter. Glomerulus + Bowman’s capsule
What parts do collection only?
Renal calyces, renal pelvis
What other main function are the kidneys in charge of?
homeostasis (pH, bp, osmolarity, expelling waste like urea)
What is the glomerulus?
Site where filtration happens
What is Bowman’s capsule and Bowman’s space? Which substances can pass thru Bowman’s capsule?
Collects filtrate/fluid that comes out of glomerulus; open space
Glucose, water and ions can pass thru, proteins can’t cuz too big for podocytes
How do nutrients in blood move from glomerulus to Bowman’s capsule?
Fenestrated endothelial cells of blood vessels, semi-permeable basement membrane (it’s neg charged to prevent proteins from entering filtrate), podocytes from tubular epithelial cells
Know the effects of inc/dec diameter of afferent/efferent arterioles on filtration rate
Aff: direct relationship, eff: inverse relationship
Know the proximal tubule, loop of Henle, and distal tubule of nephron
in thick ascending loop: salts are pumped out to salty medulla thru salt permeable membrane via ATP => active transport, thin ascending in inner medulla is passive transport; in thin descending loop: only water is pumped out in rxn to salty medulla –> water reabsorption. PCT is site of bulk reabsorption of glucose, aa, water-soluble vitamins, salt reabsorption, water excretion and HUNK secretion; DCT responds to aldosterone, salt reabsorption (ex: Na+ into filtrate and K+ into blood), water excretion and HUNK secretion
Which side of bladder do ureters connect to?
Posterior side
How is urine expelled in males and females?
Males: renal calyx –> renal pelvis –> ureters –> bladders internal urethral sphincter (smooth) –> prostatic urethra –> external urethral sphincter (skeletal) –> spongy urethra (penis) –> out
Females: renal calyx –> renal pelvis –> ureters –> bladder –> internal urethral sphincter –> external urethral sphincter –> out
Why do ureters have valves?
to prevent urine backflow; if there is backflow –> stasis –> greater risk of infection => UTI (shorter urethras also pose greater risk of infections –> more UTIs for them)
What does ADH/vasopressin do? Does aldosterone act on collecting ducts?
Increase water reabsorption; acts on collecting ducts by telling it to reabsorb water (so if ADH wasn’t present, water would nmlly be absorbed only in descending loop of Henle). Yes, it does the same thing as ADH: inc water reabsorption at collecting duct (indirectly tho); it also inc Na+ reabsorption at collecting duct
T/F: proximal tubule only collect solute, thus its not involved in osmolarity
T
Detrusor muscle
Muscular lining of bladder. It contracts cuz of parasympathetic nervous system
Micturition reflex
When IUS relaxes because stretch receptors are telling parasympathetic nervous system you need to empty bladder
Filtration vs secretion vs reabsorption
Solute moving from blood to filtrate via bowman’s capsule vs solute moving from blood to filtrate via anywhere else besides bow’s cap vs solute moving from filtrate to blood
Starling forces
What causes fluid movement into Bowman’s space. Takes account hydrostatic pressure and oncotic pressure (osmotic pressure induced by proteins)
Why is urea excreted thru urine?
When we digest proteins, ammonia becomes a byproduct from amino group. Ammonia is a base that can disturb pH —> liver converts it to urea to be excreted
Major waste products in urine. Under nml circumstances, urine should be..?
H+, urea, ammonia, K+ (HUNK). Urine should be hypertonic to blood
Countercurrent multiplier system
When loop of Henle creates a conc gradient via single effect and flow of fluid. Single effect - when Na+/K+/2Cl- cotransporter reabsorbs all 3 ions at thick ascending limb (ie. Remove the 3 ions from thick ascending limb) —> water will flow in or out of descending limb to equilibriate
This system allows urine osmolarity to exceed blood osmolarity
An excess of acetylcholamine leads to what?
Activation of all parasympathetic neurons
Erythropoietin vs thrombopoietin
Secreted by kidneys to stimulate development of erythrocytes/RBCs vs secreted by liver and kidneys to stimulate development of thrombocytes/platelets
Macula densa
Chemoreceptors in DCT where DCT touches glomerulus, sensitive to NaCl in body; they also stimulate juxtaglomerular cells to release renin —> dilate afferent arteriole to inc filtration rate (macula densa + juxtaglomerular cells = juxtaglomerular apparatus)
High vs low urine osmolarity
High urine, low Na+ vs low urine, high Na+
Relationship b/w bp and filtration rate
Low bp means low filtration rate
How does blood vol affect blood pressure?
Inc in blood vol —> inc in bp. Inc Na+ reabsorption (thanks to aldosterone) —> reduced water loss into urine —> inc in blood vol
There’s net loss of fluid in capillary fluid movement
Bc there’s more fluid being forced out of arterial end of capillary than being reabsorbed in venule end
