Renal Physiology Flashcards
(113 cards)
1
Q
A nephron consists of…
1) __________
2) __________
A
1) A renal corpuscle (initial filtering unit)
2) Tubule (vessel for moving fluid through the nephron)
2
Q
The renal corpuscle starts with the _______ which is supplied with blood via the afferent renal arterioles.
A
glomerulus
3
Q
The glomerulus protrudes into a fluid-filled capsule called ____________.
A
Bowman’s capsule
4
Q
As blood flows through the glomerulus approximately 20% filters into Bowan’s capsule, with the remaining blood leaving the glomerulus via the ____________.
A
Efferent arterioles
5
Q
The glomerulus and Bowman’s capsule are separated by a filtration barrier composed of three layers:
1) ______________
2) ______________
3) ______________
A
1) The single-celled epithelium layer
2) A non-cellular proteinaceous layer (basement membrane or basal laminae)
3) A single-celled epithelial lining called the podocytes that have numerous extensions/foot processes
6
Q
Renal tubules are hollow cylinders made of a single layer of ________ resting on a ____________.
A
epithelial cells
basement membrane
7
Q
The tubular system starts with the ___________, then the ____________, then the ________________, and finishes with the ______________.
A
proximal tubule
loop of Henle
distal convoluted tubule
collecting duct system
8
Q
The tubular system starts with the ___________, then the ____________, then the ________________, and finishes with the ______________.
A
proximal tubule
loop of Henle
distal convoluted tubule
collecting duct system
9
Q
Loop of Henle = __________+__________
A
descending limb + ascending limb
10
Q
Loop of Henle=__________+__________
A
descending limb + ascending limb
11
Q
Collecting duct System = __________+_________
A
cortical collecting duct + medullary collecting duct
12
Q
As the ascending limb merges into the distal convoluted tubule there is a specialized area of cells called the _____________.
A
macula densa
13
Q
The juxtaglomerular cells secrete the enzyme _______, often in response to signals from the macula densa.
A
renin
14
Q
The justaglomerular cells secrete the enzyme _______, often in response to signals from the macula densa.
A
renin
15
Q
The two important regions of the kidneys include…
1) ___________
2) ___________
A
1) The renal cortex (outer portion of kidney)
2) The renal medulla (inner portion of kidney)
16
Q
The two important regions of the kidneys include…
1) ___________
2) ___________
A
1) The renal cortex (outer portion of kidney)
2) The medulla (inner portion of kidney)
17
Q
The two general types of nephrons include:
1) _______________
2) _______________
A
1) juxtamedullary nephrons
2) cortical nephrons
18
Q
The _______ of the kidney contains all the renal corpuscles.
A
cortex
19
Q
Out of all nephrons, the juxtamedullary nephrons make up approximately _____%.
A
15%
20
Q
Henle’s loops pass deeply into the medulla of these nephrons.
A
juxtadmedullary nephrons
21
Q
_________ nephrons are responsible for generating an osmotic gradient in the medulla and for water re-absorption.
A
juxtadmedullary nephrons
22
Q
_________ nephrons are responsible for generating an osmotic gradient in the medulla and for water re-absorption.
A
juxtadmedullary nephrons
23
Q
Vasa recta help move ________ and ________ from the tubular fluid back into the blood.
A
salt and water
24
Q
Vasa recta help move ________ and ________ from the tubular fluid back into the blood.
A
salt and water.
25
Henle's loops do not pass deeply into the the medulla, of these nephrons.
cortical nephrons
26
_________ nephrons are involved in re-absorption and secretion but are not part of the regulation of the hypertonic medullary interstitium.
cortical
27
The kidney functions in regulation of body fluid composition through quantity and quality of urine through 4 porcesses:
1) __________
2) __________
3) __________
4) __________
1) Filtration
2) Secretion
3) Re-absorption
4) Excretion
28
The kidney functions as an endocrine organ by the release of:
1) ________
2) ________
3) ________
4) ________
1) Erythropoietin
2) Active vitamin D
3) Manufacture and release of renin
4) Release of prostaglandins
29
The release of erythropoietin from the kidney stimulates the production of ____________.
red blood cells in the bone marrow.
30
The release of active vitamin D from the kidneys maintains...
healthy bones and immune system.
31
The production and release of renin from the kidneys maintains...
blood volume and blood pressure.
32
The release of prostaglandins from the kidneys is important because prostaglandins are _______________.
chemical messengers.
33
____% of the blood ejected from the left ventricle with each heart beat goes to the kidneys.
25%
34
Some of the oxygen and nutrients in the quarter of blood ejected from the left ventricle that goes directly to kidneys will feed the kidney before it goes through the process of __________.
filtration
35
In adults glomerular filtration rate is approximately ____L/day, such that the entire volume of plasma is filtered approximately ____ times a day.
180 L/day
| 36 times a day
36
The blood pressure in the glomerular capillaries is:
glomerular hydrostatic pressure
37
Glomerular hydrostatic pressure favours:
filtration
38
The fluid pressure in Bowman's capsule is:
hydrostatic pressure
39
Glomerular hydrostatic pressure =
the blood pressure in the glomerular capillaries
40
As plasma volume increases in the glomerular capillaries, _________ pressure increases.
glomerular hydrostatic pressure
41
Presence of proteins in the glomerular capillary plasma is:
oncotic pressure
42
The pressure(s) favoring filtration include:
glomerular hydrostatic pressure (plasma volume)
43
The pressure(s) opposing filtration include:
hydrostatic pressure (Bowman's fluid volume) and oncotic pressure (plasma proteins in glomerular capillary)
44
Constriction of the AFFERENT arterioles will __________ the amount of blood entering the glomerulus, and therefore _________ glomerular capillary pressure, _________ the amount of fluid filtering across the filtration barrier and _________ glomerular filtration rate.
decrease
decrease
decreasing
decreasing
45
Constriction of the EFFERENT arterioles will __________ gomerular capillary pressure, _________ the amount of fluid filtering across the filtration barrier and _________ glomerular filtration rate.
increase
increasing
increasing
46
Increased glomerular capillary pressure results in _________ GFR (glomerular filtration rate)
increased
47
________ = total amount of any non-protein substance filtered into Bowman's space
Filtered load
48
Filtered load = _______ x ________
(Glomerular Filtration Rate) x (Plasma Concentration of Substance)
49
If the quantity of substance excreted in the urine is LESS than the filtered load, than...
re-absorption of the substance has occurred.
50
If the quantity of substance excreted in the urine is MORE than the filtered load, than...
secretion of substance has occurred.
51
If the quantity of substance excreted in the urine is EQUAL to the filtered load, than...
all of the substance was filtered with no secretion or re-absorption.
52
If the concentration of the substance in the urine is less than the original concentration in the plasma, it could indicate a _______ in renal function.
decrease
53
If the concentration of the substance in the urine is greater than should be over the normal testing frame, then potentially there are issues with the ___________.
filtration barrier (filtration barrier may be leaky).
54
Re-absorption by __________ across the tubular cells is dependent on concentration gradients of theses substances such that there is higher concentration of the substance in the tubular lumen than in the interstitum and plasma.
diffusion
55
Substances using what type of re-absorption must first pass through the luminal membrane of the epithelial cells, cross the cytosol of the cell and then cross the basolateral membrane.
Re-absorption by mediated transport
56
A variety of lipid-soluble organic substances are reabsorbed this way (ex. urea)
Re-absorption by diffusion across tubular membranes
57
Sodium moves into the cell across the luminal membrane by _______ but is actively pumped out of the cell (using _____________ ) across the basolateral membrane.
diffusion
| Na+ - K+ - ATPases
58
Many of the substances that are reabsorbed using mediated transport have a limit to how much can be moved for unit time - this limit is primarily due to the number of binding sites on the the ______________ and the number of ______________ in the cell membranes. (hint: same answer for each blank)
transporter proteins
59
Ingesting very high concentrations of vitamin C will result in an increase in vitamin C in the plasma but will also result in an increase in vitamin C in the ________ as tubular re-absorption of vitamin C has a limit.
urine
60
Secretion moves substances from the peritubular capillaries into the tubular lumen via _________ or ____________.
diffusion or mediated transport
61
The most important substances moved by secretion are ____ and ____ but other substances such as choline and creatine are also secreted.
H+ and K+
62
Secretion can require the active pumping/transport of a substance from the blood into the epithelial cells, movement of the substance through the cells and then transport of the substance across the epithelial membrane into the __________.
tubular lumen
63
Secretion into the tubular fluid of substances from the interstitium is a _________ means of moving substances out of the body than through the filtration pathway.
faster
64
Tubular cells are also capable of metabolism and can alter substances from the blood or tubular fluid and either secrete them in the altered form back into the tubular fluid or reabsorb them back into the _______.
blood
65
Primary kidney function = maintaining correct ______ and correct _______ concentrations along with filtering out unnecessary/toxic molecules
water
| electrolyte
66
movement of water through the renal system back into plasma (re-absorption) is regulated by...
movement of ions in and out of the renal tubules
67
_____ is the most important ion for water regulation in the kidneys.
Na+ (sodium)
68
Movement of Na+ and therefore ________ differs in different areas of the nephron.
water
69
Re-absorption of 2/3 of the filtered water and Na+ occurs in what part of the nephron?
Proximal tubule
70
Water moves from the lumen of the proximal tubule, through the tubular cells that make up the tubular wall, through interstitial space and into the peritubular capillary through ________.
osmosis
71
Starting at the proximal tubule, Na+ is brought from tubular lumen into the tubular cells via co-transport with __________ (secondary active transport), Na+ is then moved into interstitial space via primary active transport (______________) with K+ pumped into the cells, Na+ is then pumped into the _____________ via Na+ - K+ -ATPase.
glucose
Na+ - K+ - ATPase
peritubular capillaries
72
In the descending limb of the nephron water moves into the interstitium through simple diffusion, helped by the high interstitial osmolarity due to the active pumping of...
sodium out of the tubular fluid and into the interstitium by the thick ascending limb.
73
The thick ascending limb of the nephron is part of the...
loop of Henle
74
In the thick ascending limb of the nephron solute is pumped out but the cells are extremely impermeable to water movement; therefore, the tubular fluid becomes very ________ in this part of the renal system.
dilute (low solute, high water)
75
The only area in the nephron with active pumping of Cl- is...
the thick ascending limb
76
Mg2+ and Ca2+ are reabsorbed in the ___________ of the nephron through passive diffusion.
The thick ascending limb
77
This section of the nephron is permeable to water.
Distal convoluted tubule
78
Na+ is pumped out of this part of the nephron (with Cl- co-transport) and water follows the solute
distal convoluted tubule
79
Calcium re-absorption is controlled by PTH (parathyroid hormone) at this region of the nephron, using antiport system with sodium.
Distal convoluted tubule.
80
Controlled re-absorption of water occurs here allowing for the formation of concentrated urine ( which part of nephron?)
Collecting duct
81
Each collecting duct receives tubular fluid from many ___________.
nephrons
82
The antdiuretic hormone (ADH) signals an increase in __________ when increased water absorption is required.
aquaporins
83
Urine is collected here from the collecting ducts of the nephrons and drains into the ureter.
renal pelvis
84
Water cannot be actively transported across the tubular walls and osmosis of water cannot occur if the tubular fluid and surrounding tissue fluid are ________ to another.
isomotic
85
Water and sodium movement across the two sides (descending limb and ascending limb) of the loop of Henle regulate water and sodium reabsorption in a system known as the ______________________.
counter-current multiplier system
86
The counter-current multiplier system involves...
Kidneys are using salt/ions to increase interstitial osmolarity resulting in the movement of water out of the tubules and eventually into the bloodstream, maintaining plasma volumes and allowing for the removal of wastes through urine without taking excess water with it.
87
To help the movement of water into the bloodstream, specialized ____________ run alongside the loop of Henle (ex: vasa recta in the juxtamedullary nephrons)
blood vessels
88
Salts (solutes) build up in the interstitial tissues, therefore, more _______ leaves the descending limb, the tubular fluid becomes more concentrated (higher osmolarity and more sodium is pumped out of the ascending limb.
water
89
vasa recta have properties of both capillaries (easy water diffusion) and _________ (smooth muscle)
arterioles
90
Sodium diffuses into the descending part of the vasa recta then diffuses out of the ascending part of the vasa recta which helps to maintain high ________________.
interstitial osmolarity
91
Water diffuses into the vasa recta because of high __________ pressure.
oncotic (presence of plasma proteins - remember Starling's hypothesis for capillary regulation of water)
92
______ = a by-product of protein metabolism (by-product of transamination)
urea
93
The ascending loop of Henle is permeable to ______ as is the end portion of the collecting duct.
urea
94
44% of filtered urea is reabsorbed, 56% is excreted.
| true or false?
true
95
Urea transporters move large concentrations of urea out o the collecting duct and into the...
interstitium
96
Some urea diffuses into the ascending limb of the loop of Henle, some stays in the _____________ where it helps to increase osmolarity of the ___________.
(hint: same answer for both blanks)
interstitial space
| interstitium
97
98% of sodium is reabsorbed before the collecting ducts, the final 2% is reabsorbed in the collecting ducts through formation of...
sodium transporters as a result of aldosterone stimulation.
98
90% of K+ is reabsorbed in the _________ of the loop of Henle. The remaining 10-20% is...
proximal tubule
| excreted into the urine
99
K+ can be secreted by the cortical collecting ducts therefore changes to the concentration of K+ in the urine is usually due to changes in...
the secretion by the cortical collecting ducts
100
Decreased K+ in the plasma results in decreased __________ and increased ______________ by the cortical collecting ducts.
K+ secretion
| K+ re-absorption
101
Changes to K+ secretion or re-absorption is under the control of ___________ (hormone) and linked to Na+ movement.
aldosterone
102
Increasing plasma K+ concentrations results in stimulation of the adrenal cortex and increased levels of ___________ are secreted. Increased plasma levels of ___________ result in increased production of __________ pumps and increased secretion of _____ by the collecting ducts. (hint: first two blanks are same answer)
aldosterone
aldosterone
Na+ - K+ pumps
K+
103
60% of plasma Ca2+ is filterable, the rest is bound to __________.
plasma proteins
104
98-99% of the filtered Ca2+ is reabsorbed most before...
the collecting ducts.
105
What are the two hormones that play a role in regulating plasma Ca2+ concentrations?
Parathyroid hormone and active vitamin D.
106
Decreased plasma calcium stimulates the ___________ gland, increasing the secretion of _______________.
parathyroid gland
| parathyroid hormone
107
At the renal level, increased parathyroid hormone results in increased re-absorption of __________ and decreased urinary excretion of __________. (hint: same answer for both blanks)
calcium
| increasing plasma calcium levels
108
At the renal level, increased parathyroid hormone results in decreased re-absorption of __________ and increased urinary excretion of ___________. (hint: same answer for both blanks)
phosphate
| decreasing plasma phosphate levels
109
Parathyroid hormone causes activation of ________ which directly affects calcium absorption in the intestine leading to an increase in plasma calcium levels.
vitamin D
110
If plasma Ca+ is released _____________ decreases, affecting both the renal system and the bones of the body.
Parathyroid hormone decreases
111
Kidneys balance the H+ ions (maintaining constant plasma [H+] through alteration of ___________ concentrations in the plasma).
bicarbonate
112
If plasma H+ decreases (alkalosis), the kidneys __________ excretion of ________.
increase
| HCO3-
113
If plasma H+ increases (acidosis), the kidneys __________ excretion of ________ and kidney tubular cells produce new ______ and add it to the plasma.
stop
HCO3-
HCO3-
