lecture 18 Flashcards

1
Q

what are the four main functions of the excretory system

A
  1. regulate volume of the fluid in the body 2. maintain individual solutes (CA2+, NA+, H+) at appropriate concentrations 3. regulate solute concentration in extracellular fluid (osmolarity) 4. eliminate nitrogenous waste
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

an excretory systems ability to change ECF composition depends on

A

its ability to make a dilute or concentrate urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

ALL vertebrates can make a urine

A

less concentrated than the ECF, therefore concentrate the ECF (U/P<1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

kidneys of mammals and birds ONLY can also make urine

A

more concentrated urine than the ECF there fore can dilute the ECF via the kidneys (U/P>1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what does u/p = 1 mean

A

150 mM, no net ECF concentration change, what you put in is what you take out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what does u/p > 1 mean

A

300 -> 150 mM ECF conc is decreased, more salt less water so you get rid of salt and keep h20

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what does u/p < 1 mean

A

50 -> 150 mM ECF conc is increased water is more salt is less, you take out water and keep salt

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what does the U and P stand for

A

urine and plasma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what i the functional unit of kidneys

A

nephrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what do nephrons consist of

A

renal tubules and surrounding blood vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how is urine produced

A

by filtering blood plasma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

where does ultrafiltration occur

A

glomerulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

after ultrafiltration, where does the plasma go

A

water and solutes are pushed into BOWMANS capsule by blood pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what do renal tubules do

A

they selectively secrete and reabsorb solutes and water to form urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what do the proximal segments of vertebrate tubules do

A

they reabsorb salt water and nutrients back into blood while leaving toxins in the tubules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

terrestrial animals that drink a lot of fresh water must produce

A

lots of volumes of dilute urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

the late tubules of ALL vertebrates can make urine with what ratio

18
Q

diuresis

A

a state in which dilute urine is made to eliminate excess water and conserve salts

19
Q

where does diuresis and antidiuresis occur

A

the distal/late tubules

20
Q

in diuresis what happens in the kidneys

A

osmosis of water doesnt happen (means that water isnt reabsorbed) but active trasport of NaCI yes!

21
Q

vertebrates in dry environments must conserve water by

A

producing very little urine that as very concentrated

22
Q

the most concentrated urine that fish and amphibians can make is

A

u/p is equal to one

23
Q

antidiuresis

A

the state in which concentrated urine is made to conserve water

24
Q

how is antidiuresis achieved

A

by increasing water permeability (osmosis of water) in the distal tubules

25
distal tubules can add or remove what
water channels of aquaporins to become more or less permeable to water
26
what hormone regulated these aquaporins
ADH or antidiuretic hormone
27
why does body do all of this renal stuff
homeostasis
28
ADH is how we regulate
water and salt levels in our bodies
29
what kind of feedback is this renal stuff
negative
30
what happens if water level drops
ADH is released and kidneys absorb more water
31
what happens if water level rises
ADH is released less and kidneys reabsorb less water
32
diuresis has
low ADH so few aquaporins, dilute urine u/p<1
33
antidiuresis has
high ADH so more aquaporins , more conc urin u/p=1
34
how do mammals and birds get a u/p>1 4 steps
1.they use the loop of henle to create a concentration gradient in the medulla of the kidney 2.the collecting ducts pass through tissue that is increasingly high conc 4. resulting urine is more conc than plasma
35
what is the toxic byproduct of amino acid and protein metabolism
ammonia
36
what do fish do with ammonia
they have a bunch of water to dissolve it in so they keep the ammonia
37
what do mammals do with ammonia
they change it to urea
38
what do reptiles and birds do with ammonia
they change it to uric acid
39
what nitrogenous compounds are more energetically costly (most to less)
uric acid, urea, and ammonia
40
what nitrogenous compounds need more water (most to less)
ammonia, urea, uric acid
41
urine that exits the proximal tubules is
lower volume and same conc as plasma
42
urine that exits distal tubules is
influenced by homeostatic mechanisms to be more dilute or conc