BIO 669 Q&A
What does glomerulotubular balance do? - answer-adjusts sodium and water
reabsorption
As gfr drops= higher sodium and water reabsorption
As gfr increases= less sodium and water reabsorption
What does the descending loop of henle do? - answer-permeable to water and
increases concentration enhancing water reabsorption
What does the ascending loop of henle do? - answer-actively pumps sodium out= loss
of salt and retention of water that changes concentration (much more diluted water)
What is the glomerular filtration membrane made up of? - answer-3 layers:
1. Inner capillary endothelium
2. Basement membrane
3. Outer capillary endothelium- podocytes and epithelial cells= filtration slits.
What are filtration slits? - answer-gaps of podocyte that allow for more filtration of small
molecules ( sodium and glucose) out, but large molecules (blood, globulins etc) stay in.
What is the juxtaglomerular apparatus made up of? - answer-juxtaglomerular cells and
macula densa
What does the distal convoluted tubule do? - answer-reabsorbs ions/water and
regulates water/electrolyte balance
What does the loop of henle do? - answer-concentrates or dilutes urine
Descending loop= not allowing water to leave
In ascending loop forcing sodium out
What does the distal tubule do? - answer-dilutes or concentrates urine and produces
uromodulin
What is uromodulin (tamm-horsfall protein)? - answer-immunoprotein that helps prevent
uti and kidney stones
What does the collecting duct do? - answer-collects urine from the nephrons
What is filtration? - answer-pressure of fluid against a membrane forcing fluid against a
membrane and separating substances from that fluid based on size.
Where do the interlobar arteries run? - answer-between pyramids
, What do interlobar arteries do? - answer-supply blood to the arcuate arteries
What do the arcuate arteries do? - answer-help to define that border between the cortex
and the medulla
What causes pressure in the efferent arterioles? - answer-smooth muscle, smaller=
back pressure
What causes pressure in the afferent arterioles? - answer-in flow
What are peritubular capillaries? - answer-low-pressure, porous capillaries adapted for
absorption of water and solutes
Arise from efferent arterioles
Cling to adjacent renal tubules in cortex
Empty into venules
What does the vasa recta do? - answer-maintains the osmotic gradient
Delivers blood to the cells in the area
What do the ureters do? - answer-transport urine to the urinary bladder, where urine is
stored before urination through the urethra to the outside.
What makes up the ureter? - answer-long intertwining smooth muscle bundles that
helps to set up peristalsis to help move urine down to bladder
What is micturation? - answer-the act of peeing.
What are the detrusor muscles? - answer-walls within the bladder
What is the trigone? - answer-smooth trigangular area outlined by the openings for the
ureters and the urethra.
Infections tend to persist in this region.
What are the areas of the urethra in men? - answer-the prostatic, the membranous, and
the penile urethra
How does renal blood flow determine renal filtration rate? - answer-as renal blood flow
is increased you are able to filter more that flood= increased rate of filtration.
How does the kidney keep a steady state of filtration and blood flow? - answer-the
smooth muscle of the renal artery contricts (if hydrostatic pressure is high to decreased
flow and filtration) of dilates (if hydrostatic pressure is low to increase flow and filtration)
to keep consistent.
What does glomerulotubular balance do? - answer-adjusts sodium and water
reabsorption
As gfr drops= higher sodium and water reabsorption
As gfr increases= less sodium and water reabsorption
What does the descending loop of henle do? - answer-permeable to water and
increases concentration enhancing water reabsorption
What does the ascending loop of henle do? - answer-actively pumps sodium out= loss
of salt and retention of water that changes concentration (much more diluted water)
What is the glomerular filtration membrane made up of? - answer-3 layers:
1. Inner capillary endothelium
2. Basement membrane
3. Outer capillary endothelium- podocytes and epithelial cells= filtration slits.
What are filtration slits? - answer-gaps of podocyte that allow for more filtration of small
molecules ( sodium and glucose) out, but large molecules (blood, globulins etc) stay in.
What is the juxtaglomerular apparatus made up of? - answer-juxtaglomerular cells and
macula densa
What does the distal convoluted tubule do? - answer-reabsorbs ions/water and
regulates water/electrolyte balance
What does the loop of henle do? - answer-concentrates or dilutes urine
Descending loop= not allowing water to leave
In ascending loop forcing sodium out
What does the distal tubule do? - answer-dilutes or concentrates urine and produces
uromodulin
What is uromodulin (tamm-horsfall protein)? - answer-immunoprotein that helps prevent
uti and kidney stones
What does the collecting duct do? - answer-collects urine from the nephrons
What is filtration? - answer-pressure of fluid against a membrane forcing fluid against a
membrane and separating substances from that fluid based on size.
Where do the interlobar arteries run? - answer-between pyramids
, What do interlobar arteries do? - answer-supply blood to the arcuate arteries
What do the arcuate arteries do? - answer-help to define that border between the cortex
and the medulla
What causes pressure in the efferent arterioles? - answer-smooth muscle, smaller=
back pressure
What causes pressure in the afferent arterioles? - answer-in flow
What are peritubular capillaries? - answer-low-pressure, porous capillaries adapted for
absorption of water and solutes
Arise from efferent arterioles
Cling to adjacent renal tubules in cortex
Empty into venules
What does the vasa recta do? - answer-maintains the osmotic gradient
Delivers blood to the cells in the area
What do the ureters do? - answer-transport urine to the urinary bladder, where urine is
stored before urination through the urethra to the outside.
What makes up the ureter? - answer-long intertwining smooth muscle bundles that
helps to set up peristalsis to help move urine down to bladder
What is micturation? - answer-the act of peeing.
What are the detrusor muscles? - answer-walls within the bladder
What is the trigone? - answer-smooth trigangular area outlined by the openings for the
ureters and the urethra.
Infections tend to persist in this region.
What are the areas of the urethra in men? - answer-the prostatic, the membranous, and
the penile urethra
How does renal blood flow determine renal filtration rate? - answer-as renal blood flow
is increased you are able to filter more that flood= increased rate of filtration.
How does the kidney keep a steady state of filtration and blood flow? - answer-the
smooth muscle of the renal artery contricts (if hydrostatic pressure is high to decreased
flow and filtration) of dilates (if hydrostatic pressure is low to increase flow and filtration)
to keep consistent.
