Nephron & Osmoregulation Notes Flashcards
(110 cards)
1
Q
osmoregulation: balancing levels of … and … in the body; typically removes …. from body through process called …
A
water; salts; metabolic wastes; excretion
2
Q
breakdown of nitrogen-containing molecules (e.g. …. and ….), results in excess …. that must be excreted; depending on species, this excess may be excreted as …, …, or …
A
amino acids; nucleic acids; nitrogen waste; ammonia; urea; uric acid
3
Q
ammonia is formed with …. energy by addition of …. to …. removed from …
A
little to no; hydrogen ions; amino groups; amino acids
4
Q
ammonia is …, but is ok as excretory product if there is sufficient … to … it from the body –> therefore, … and … animals, for the most part, excrete ammonia
A
toxic; water; wash; fish; aquatic
5
Q
urea is excreted by: …, …, and ….
A
sharks; mammals; adult amphibians
6
Q
urea is much less … than ammonia, and can be excreted in moderately …. solution
A
toxic; concentrated
7
Q
urea conserves …., but requires expenditure of ….
A
body water; energy
8
Q
urea is produced in the … by a set of energy-requiring … reactions known as the ….
A
liver; enzymatic; urea cycle
9
Q
urea cycle: carrier molecules take up … and 2 … molecules, releasing …
A
carbon dioxide; ammonia; urea
10
Q
uric acid: synthesized by long, complex series of enzymatic reactions that requires an even greater amount of … than urea synthesis
A
energy
11
Q
uric acid is not very … and is nearly …., thus allowing for further
A
toxic; insoluble; water conservation
12
Q
uric acid can be more … than urea
A
concentrated
13
Q
uric acid excreted by …, …, and …
A
insects; reptiles; birds
14
Q
reptiles and birds: dilute solution of uric acid passes from kidneys to … (reservoir for products of the …, …., and … systems)–> these contents are then refluxed into the …., where … is reabsorbed
A
cloacal; digestive; urinary; reproductive; water
15
Q
production of insoluble, mostly nontoxic uric acid is advantageous for shelled embryos because all …. are stored in the … until hatching
A
nitrogenous wastes; shell
16
Q
kidneys are connected to the …. –> duct that transports urine to …., which is then stored there until excreted through the …
A
ureter; urinary bladder; urethra
17
Q
kidneys have 3 parts:
…. –> outer region of the kidney
…. –> lies on inner side of … (middle of kidney), comprised of 6-10 ….
….. –> innermost part of kidney, where urine is collected and carried to bladder via a ureter; ….
A
renal cortex; renal medulla; renal cortex; renal pyramids; renal pelvis; hollow chamber
18
Q
each kidney is composed over over …. tubules called nephrons –> basic …. of the kidney
A
1 million; functional unit
19
Q
nephrons produce
A
urine
20
Q
structure of nephrons: … –> …. –> … –> … –> … (this then goes to ….)
A
glomerular capsule; proximal convoluted tubule; loop of Henle; distal convoluted tubule; collecting duct; renal pelvis
21
Q
each nephron has its own blood supply –> …. branching from …
A
arterioles; renal artery
22
Q
arterioles (afferent arterioles) divide to form a capillary bed called the …. which drains into an efferent arteriole which branches into a second capillary bed around tubular parts of nephron (….)
A
glomerulus; peritubular capillaries
23
Q
fundamental process of urine formation: initially … large amount of … and … out of the blood, and then …. much of the materials
A
filtering; water; solutes; reabsorbing
24
Q
urine production involves 3 distinct processes:
- ….
- tubular … at convoluted tubules
- tubular …. at convoluted tubules
A
glomerular filtration; reabsorption; secretion
25
glomerular filtration: movement of small molecules across glomerular wall into .... due to ....
includes: ..., ..., ..., and ....
bowman's capsule; blood pressure; water; nutrients; salts; wastes
26
glomerular walls are ... more permeable than walls of most capillaries in the body
100x
27
molecules that enter the bowman's capsule --> ....
| DOES NOT include: .... and ....
glomerular filtrate; plasma proteins; red blood cells
28
Total blood volume averages about .... liters and this is filtered every ... minutes --> ... liters of filtrate produced daily
5; 40; 180
29
osmolarity: measure of the potential for ....; water tends to move from a solution with ... osmolarity into a solution with ... osmolarity
osmosis; low; high
30
initially, osmolarity of filtrate and blood are nearly equal, so osmosis does not occur. Sodium ions are actively pumped into .... and chloride follows .... --> adjusts blood osmolarity, such that water passively moves ....
... to ... % of salt and water is reabsorbed in the ...
peritubular capillary; passively; into blood; 60; 70
31
At PCV, nutrients (e.g. ... and ....) return to the .... --> only molecules recognized by carrier proteins are actively ...
glucose; amino acids; blood; reabsorbed
32
cells of PCV have many microvilli to increase .... and many mitochondria to supply ... needed for active transport
surface area; energy
33
glucose is ordinarily completely reabsorbed: BUT, if there is more glucose than be handled by carriers (as in diabetics), it appears in ...., which results in .... being reabsorbed
urine; less water
34
Urea .... reabsorbed (about ...% of that filtered)
passively; 50
35
tubular secretion: a 2nd way by which substances are removed from ... and added to ....
blood; tubular fluid
36
substances eliminated by tubular secretion: ..., ...., ...., ...., ..., ....
uric acid; H+, NH3 (ammonia), creatinine, histamine, penicillin
37
tubular secretion helps rid the body of harmful compounds that weren't
filtered into the glomerulus
38
kidneys maintain homeostasis in 4 ways:
1. excrete .... such as ....
2. maintain ...-... balance, which affects ... and ...
3. maintain ...-..., and thus, ..., balance
4. secrete .... (e.g. erythroprotein, which stimulates stem cells in bone marrow to produce more red blood cells)
metabolic wastes; urea; water-salt; blood volume; blood pressure; acid-base; pH; hormones
39
excretion of hypertonic urine is dependent on reabsorption of ... from .... and ....
water; loop of Henle; collecting duct
40
during water reabsorption process, water passes through channels called ...
aquaporins
41
Loop of Henle: penetrates deep into ... and has ... and .... loops
medulla; descending; ascending
42
in thin part of ascending loop, NaCl ... diffuses out into .... But, the thick portion of this loop ... transports salt out into the medulla
passively; interstitial fluid; actively
43
As fluid moves up thick portion of the ascending loop, ....salt is available for transport --> creates ....
less; osmotic gradient
44
gradient: concentration of salt is greater in direction of ....; because of this gradient, water leaves the ....
inner medulla; descending limb
45
countercurrent mechanism in loop of Henle: As water diffuses out of descending loop, the remaining fluid in the loop continually encounters a greater ... in the medulla and continues to ....
solute concentration; leave the descending loop
46
filtrate in collecting duct faces the same gradient, causing the urine in the collecting duct to become .... to ....
hypertonic; blood plasma
47
Antidiuretic hormone (ADH): released by posterior lobe of pituitary in response to .... in the blood
increased concentration
48
ADH presence causes more water to be ... and decreased amount of more ... urine is produced; this can occur through the insertion of more ... into epithelial cells of ... and ....
reabsorbed; concentrated; aquaporins; distal tubule; collecting duct
49
ADH is useful during
dehydration
50
more than ... of sodium ions is reabsorbed, ...% reabsorbed at PCT, ...% at ascending loop, and remaining at DCT & ....
99%; 67; 25; collecting duct
51
salt reabsorption regulates ... and ...
blood volume; pressure
52
when blood pressure is insufficient to promote ...., a cluster of cells near glomerulus (juxtaglomerular apparatus) secretes ...
filtration; renin
53
renin: enzyme that converts angiotensinogen into angiotensinogen I, which is later converted to angiotensinogen II to release ...
aldosterone
54
aldosterone: hormone that promotes excretion of ... and reabsorption of ... at .... Reabsorption of ... leads to reabsorption of ..., thereby increasing ... and ....
potassium ions; sodium ions; DCT; sodium ions; water; blood volume; blood pressure
55
Atrial Natriuretic Hormone (ANH): hormone secreted when cardiac cells are stretched due to .... --> inhibits secretion of .... and promotes excretion of ... (....), which consequently decreases .... and ... by simultaneously excreting ...
increased blood volume; renin; sodium ions; natriuresis; blood volume; pressure; water
56
only kidneys can rid body of wide range of .../... substances: slower than buffer/breathing mechanism, but more powerful impact on pH
acidic; basic
57
kidneys reabsorb ... and excrete ... to maintain normal ... if blood is .... (if blood is basic, ... is not excreted and .... is not reabsorbed)
bicarbonate; H+; blood pH; acidic; H+; bicarbonate
58
urine is typically .... --> usually an excess of ... is excreted (... and .... buffer these in the urine)
acidic; H+; ammonia; phosphate
59
negative feedback: outcome ... what is happening
| e.g. in case of .... during ..., there is negative feedback
reverses; ADH release; dehydration
60
positive feedback: outcome ... what's already happening
enhances
61
glomerulus: tuft of blood capillaries located within the ..., a sac at the end of the nephron
bowman's capsule
62
(glomerulus) is is between arterioles which deliver the blood to the glomerulus. When blood enters, pressure moves small molecules (e.g. ...., ..., ..., ..., ..., ..., ..., ..., ... & ..., ... - these end up going into urine) from the glomerulus into the lumen of the bowman's capsule to achieve filtration
sodium; chloride; potassium; bicarbonate; water; glucose; amino acids; ammonia; toxins; drugs; urea;
63
glomerulus maintains a constant rate of
filtration
64
bowman's capsule: ... the filtrate. Consists of two layers of cells: one that closely covers the ..., and another that is continuous with the inner layer
absorbs; glomerulus
65
proximal convoluted tubule: this is where ... of fluids from the nephron back to the ... occurs, which therefore recovers much of the ....
tubular reabsorption; blood; glomerular filtrate
66
the pct is lined by cells with many .... and ....
mitochondria and microvilli
67
With carrier proteins and ion exchangers, solutes are reabsorbed in the pct. This is essential to ensure that an individual does not lose most of their
extracellular bodily fluids
68
Things that are reabsorbed in PCT: active- ..., ..., ..., ....
passive: ... (....), ..., .... (....)
both active and passive, respectively: ...
hydrogen; urea; potassium; amino acids; glucose; facilitated diffusion; water; bicarbonate; facilitated diffusion; sodium & chlorine
69
secretory product of PCT: .... --> counters ... in interstitial fluid
ammonia; hydrogen reabsorption
70
90% of bicarbonate reabsorbed because it acts as a ... --> moved through .... transport using ....
buffer; passive; channels
71
ions that are reabsorbed at pct get pushed into the ...
medulla
72
descending & ascending loops of henle: countercurrent multiplication here creates the osmotic gradient that ....
concentrates urine
73
as a whole, the loop of henle recovers ... and .... from the urine
water; salt
74
countercurrent exchange in loop of henle increases
osmolarity
75
Vasa recta carry blood in opposite directions, and absorb ... on one hand and ... on the other, thus enabling the countercurrent mechanism to be sustained
water; solute
76
vasa recta: ... in medulla --> interacts with ..., mostly associated with ...
capillaries; peritubular capillaries; thin part of loop of henle
77
peritubular capillaries are more responsible for
bringing blood to kidney
78
water moved out of the descending loop is carried away by the ..., which then maintains the countercurrent multiplier
vasa recta
79
sodium chloride int he ascending loop is permeable initially, therefore moving out .... but then active transport becomes necessary as changes in ... occurs, which happens in the ... region of the ascending tube
passively; interstitial fluid; thicker
80
descending loop of henle: ... reabsorbed ere, tons of .... to maximize water transport
water; aquaporins
81
blood in vasa recta is travelling countercurrent to filtrate in descending loop, there is also countercurrent exchange between the
ascending and descending loops
82
in ascending loop, ... is reabsorbed (both active and passive)
countercurrent exchange takes place with the ..., ...., and with the ....
sodium chloride; descending loop; collecting tubules; vasa recta
83
distal convoluted tubule: impermeable to ...., reabsorbs ..., ... and ... and then regulates the pH of urine by secreting ... and absorbing ....
water; calcium; sodium; chloride; protons; bicarbonate
84
DCT regulates .... and ... homeostasis, permeable to many different ...
extracellular fluid volume; electrolyte; solutes
85
```
DCT: bicarbonate reabsorption is ... because 90% was already reabsorbed
other reabsorbed things:
passive- ..., ...
active- ... & ..., ...., ..., ...
... is reabsorbed as well
```
active; glucose; water; sodium; chloride; amino acids; potassium; hydrogen; ammonia
86
secretory product of DCT: ... (...) again maintaining pH
hydrogen; active
87
potassium reabsorption in DCT allows for proper reabsorption of
sodium chloride
88
collecting duct: fluid leaving the DCT flows into these which collect .... It channels the urine into the ... for drainage into ...
urine; renal pelvis; ureters
89
collecting duct also adjusts the .... of the urine by ....
salinity; reabsorbing water
90
collecting duct leading into urine is where .... stops--> rest of the process from here on out is simply ...
countercurrent exchange; transport
91
reabsorption at collecting ducts:
passive: ..., ....,
active: ....
urea; water; sodium chloride
92
permeability of water at collecting ducts is under hormonal control --> ....
antidiuretic hormone (ADH)
93
ADH decreases ... into urine
water output
94
nephron: unit of ... and ... of the kidney
structure; function
95
peritubular capillaries: (peri- around, tubular- tube) interacts with/surrounds: ....
convoluted tubules
96
peritubular capillaries involved in countercurrent exchange:
- 2 tubes: ... and ...
going in opposite directions
- fluid; ... and ....
nephron; capillaries; blood; filtrate
97
glands on top of the kidney:
adrenal glands
98
80 km of convoluted tubules suggests lots of
folding
99
epithelial wall in capillaries allows for ... and indicates ...
exchange; permeability
100
reabsorption because absorption of materials into blood first done in
digestive system (all of these materials go into the kidney)
101
what does the ADH actually regulate?
| ADH regulates .... --> looking for concentration of ...., ..., and ...
osmolarity; salt; glucose; urea
102
How is osmolarity detected? And where is the detector located in the human body?
Detected by ..., located in the .... (detects the amount of .... in the .... -- controls how much ... is secreted because it makes ...)
osmoreceptors; hypothalamus; water; blood; ADH; ADH
103
osmoreceptors bind to ... (e.g. ..., ..., ...)
ligand (a molecule that binds to other - larger, molecules); glucose; sodium; urea
104
ADH goes to ..., goes to ..., and then interacts with ...., changes .... of .... --> water is ... and then goes back to ....
posterior pituitary gland; blood; collecting duct; gene expression; aquaporins; reabsorbed; peritubular capillaries
105
what is normal range of osmolarity?
| ... mOsm/L --> anything above this is too ...
300; high
106
When would ADH be released? Describe red blood cell/ blood plasma.
- At ... mOsm/L --> suggests ..., due to ...
- Red blood cell has ... solute (...), blood plasma is ...., thus causing water to move ... of the cell and into the ...
300; dehydration; breathing; less; hypotonic; hypertonic; out; blood plasma
107
what would count as triggering the opposite (of ADH release)? Describe blood/cell?
- Decrease in ... --> ... (....- needing to release more ...)
- Cells would be ..., blood plasma would by ... and cells could ... (would cause ....)
blood osmolarity; overhydrated; diuresis; water; hypertonic; hypotonic; burst; death
108
Things that could cause urine dilution (diuretics): ..., ..., ... (due to large amounts of ...), overconsumption of ...
alcohol; caffeine; soda; sugar; water
109
Hypo-osmotic: ... mOsm/L
70
110
increase rate of ..., but no .... in diuresis situation
filtration; hormonal control
