EXAM 4 - urine formation Flashcards
Match each process with its definition.
a) Once filtration has been completed, this is used if something needs to be send out of blood anyway.
b) Happens only in the renal corpuscles; it consists in removing many elements from blood to make the filtrate.
c) This happens when something was removed from blood but is still needed by the body.
a) Secretion
b) Filtration
c) Reabsoption
true or false about filtration
1) The glomerulus is made of permeable venules that let 10 to 20% of the plasma go through their walls.
2) Looking at the filtrate that accumulates in the glomerular capsule, it is frequent to observe red blood cells and white blood cells.
3) The plasma proteins that maintain blood osmolarity are not filtered in the glomerulus.
1) False
2) False
3) True
true or false about filtration
4) Blood hydrostatic pressure is the main force driving plasma out of the glomerulus.
5) A decrease in blood pressure has no effect on glomerular filtration.
6) The rate of glomerular filtration varies according to the osmolarity the filtrate has in the distal convoluted tubule.
4) True
5) False
6) True
The proximal convoluted tubule reabsorbs large quantities or water and solutes. Which ion plays a huge role in driving their reabsorption?
a) Hydrogen
b) Potassium
c) Sodium
d) Water
e) Calcium
c) Sodium
True or false on reabsorption and secretion
1) Most of the reabsorption happens in the proximal convoluted tubule.
2) Reabsorption and secretion happen in all parts of the nephron.
3) Reabsorption is always performed using diffusion and secretion using active transport.
4) Reabsorption happens in distal convoluted tubule, but a lot less than in the proximal convoluted tubule.
5) Most of the water and solutes filtered by the glomerulus get reabsorbed and never reach the urine.
1) True
2) False
3) False
4) True
5) True
True or false on reabsorption and secretion
6) Descending and ascending parts of the loop of Henle have thin and thick portions; this influences where reabsorption and secretion happen.
7) Water reabsorption is possible in collecting duct; thanks to ADH and aquaporins.
8) In order to perform reabsorption efficiently, the proximal convoluted tubule has microvilli on its cells.
9) The distal convoluted tubule is the last chance for a substance to be secreted.
6) True
7) True
8) True
9) True
Among the substances below, which should not be found in high concentration in urine.
a) Glucose
b) Vitamins
c) Proteins and amino acids
d) Sodium
e) Urea
c) Proteins and amino acids
a) Glucose
b) Vitamins
Antidiuretic hormone, ______, production is triggered when ________ of the __________ detect an ____________
in blood osmolarity. This prompts the secretion of ADH from the _________. ADH then travels through the bloodstream and reaches the kidneys’ ___________. Cells of this structure, then start inserting _____________
in their __________ . To understand what happens next, one needs to know that the _________________ of the interstitial fluid around the ______________ increases as urine flows towards the __________________. This element is key to water __________ using __________________ . As it travels down ___________, urine concentration ___________. In the end, when secreted, ADH has an impact on blood and urine osmolarity, but also on blood pressure.
ADH
osmoreceptors
hypothalamus
increase
posterior pituitary
COLLECTING DUCTS
aquaporins
cell membrane
osmolarity
collecting ducts
minor calyces
reabsorption
osmosis
collecting ducts
increases
True or False.
in the collecting duct, water reabsorption happens because of the permanent aquaporins found in the cells’ plasma membranes.
FALSE
It is true that water can exit the collecting duct using aquaporins, but for the aquaporins to be found in the cell membranes, ADH must be secreted. Aquaporins are not permanent in the collecting duct.
Select all the events that happen in the distal convoluted tubule.
.
a) Some more water gets reabsorbed in DCT.
b) Bicarbonate ions can be reabsorbed if needed.
c) Hydrogen ions can be secreted if needed.
d) Drugs breakdown products get secreted.
e) All of the above can happen in DCT.
e) All of the above can happen in DCT.
The nephron loop plays a huge role in water and sodium reabsorption. It does so by using a system call the countercurrent multiplier.
true or false?
Osmolarity of the medulla increases as you get closer to the tip of the nephron loop.
In the ascending loop, osmolarity of the filtrate decreases because of sodium reabsorption.
The ascending part of the loop contains many sodium-potassium pump.
The descending part of the loop contains permanent aquaporins.
At the end of the loop, the filtrate is hypoosmotic. We can also say that is it hypotonic compared to blood.
In the descending loop, osmolarity of the filtrate increases because of water reabsorption.
all true
