Ion and Water Balance 1 Flashcards
(78 cards)
1
Q
animal environment
A
- external world outside the whole animal
2
Q
cell environment (2)
A
- extracellular fluid for a cell
- plasma and interstitial fluid
3
Q
intracellular enzyme environment (2)
A
- cytoplasm
- intracellular fluid
4
Q
how do animals control ion and water balance in internal/external environments
A
- use different combinations of tissues
5
Q
what is the general combination of tissues used to control ion/water balance in animals (5)
A
- mucus
- apical membrane
- basolateral membrane surrounded by interstitial fluid
- endothelium
- plasma and blood cells
6
Q
homeostatic processes (3)
A
- osmotic regulation
- ionic regulation
- nitrogenous waste excretion
7
Q
homeostatic processes: osmotic regulation
A
- osmotic pressure of body fluids
8
Q
homeostatic processes: ionic regulation
A
- concentrations of specific ions
9
Q
homeostatic processes: nitrogenous waste excretion
A
- excretion of end-products of protein metabolism
10
Q
how do solutes move through water
A
- by diffusion
11
Q
rate of diffusion
A
dQs/dt
12
Q
Fick Equation for the rate of diffusion
A
dQs/dt = Ds x A x (dC/dX)
13
Q
diffusion coefficient
A
- takes into account the size of the molecule and hydration shell
14
Q
Ds
A
- diffusion coefficient
15
Q
A
A
- diffusion area
16
Q
dC/dX (2)
A
- size of the concentration gradient
- X is the distance
17
Q
what does the direction of diffusion depend on
A
- the concentration gradient
18
Q
what forces will affect the movement of water across a semipermeable membrane (2)
A
- osmotic pressure pushing water toward an area of higher solute concentration
- gravity pushing water down
19
Q
hyperosmotic
A
- solution with higher osmolarity
20
Q
hypoosmotic
A
- solution with lower osmolarity
21
Q
isosmotic
A
- when the osmolarities of two solutions are the same
22
Q
what kind of solution does water diffuse from/into
A
- water diffuses from a hypoosmotic solution to a hyperosmotic solution
23
Q
tonicity
A
- the affect of a solution on cell volume
24
Q
hypertonic solution
A
- solution outside the cell has higher concentrations of solute
25
hypotonic solution
- solution outside the cell has lower concentrations of solute
26
isotonic solution
- solution outside the cell has the same concentrations of solute as inside the cell
27
how does the cell behave in hypertonic solutions (2)
- cell shrinks
- water leaves the cell by osmosis
28
how does the cell behave in hypotonic solutions (2)
- cell swells
- water enters the cell by osmosis
29
how does the cell behave in isotonic solutions (2)
- cell neither shrinks nor swells
- no net osmosis
30
what can occur when RBCs are in hypertonic solutions (2)
- cell shrinks
- Hb can crystallize due to high concentrations inside RBC
31
why is it important to regulate cell osmolarity (2)
- increased intracellular osmolarity can directly **interfere with cellular processes**
- result in water movement across membrane, **changing cell volume**
32
what cellular processes can be interfered during increased intracellular osmolarity (2)
- protein-protein interactions
- cellular fluidity for diffusion
33
what cell implications occur after moderate swelling
- disruption of membrane
34
what cell implications occur after excessive swelling
- cell lysis (pops)
35
what cell implications occur after excessive cell shrinking
- macromolecular crowding
36
what can macromolecular crowding result in
- less efficient and impaired cell functioning
37
how do cells control their volume (2)
- transport solutes in and out of extracelullar fluid (ECF)
- water follows solutes by osmosis
38
how do animals regulate their cells' volumes (2)
- regulate the composition of the ECF
- provides cells with a constant external solution that allows them to maintain appropriate cell volume
39
what structures do animals use to regulate their ECF (2)
- mammals use kidneys
- fish use gills
40
what ions do cell move to regulate ions/water when ECF isn't constant (4)
- sodium (Na+)
- potassium (K+)
- chloride (Cl-)
- calcium (Ca2+)
41
what transporters are used to regulate sodium (2)
- 3 Na+/2 K+ ATPase
- Na+/H+ exchanger
42
what transporters are used to regulate potassium
- 3 Na+/2 K+ ATPase
43
what transporters are used to regulate chloride
- generally distributed passively according to the Goldman equation
44
what transporters are used to regulate calcium (2)
- Na+/Ca+ antiporter
- Ca2+ ATPase
45
what is the NKCC transporter
- Na+/K+/2Cl- cotransporter
46
active increase of cell volume by import of ion
- regulatory volume increase (RVI)
47
regulatory volume increase process (2)
1. cells actively import ions
2. water follows ions passively
48
RVI transporters (4)
- usually achieved by activating NKCC cotransporter
- Na+ channels
- Cl- channels
- Na+/H+ exchangers
49
active decrease of cell volume by exporting ions
- regulatory volume decrease (RVD)
50
regulatory volume decrease process (2)
1. cells actively export ions
2. water follows ions passively
51
what is the usual mechanism of RVD (5)
1. opening of K+ channels
2. K+ leaves cell down electrochemical gradient
3. water follows passively
4. inside becomes too negative
5. Cl- channels open and Cl- leaves due to hyperpolarizing effects of K+ movement
52
RVD transporters
- K+ channels
- Cl- channels
- K+/Cl- co-transporters
- Na+/Ca2+ exchanger
- Ca2+ ATPase
- Na+/K+ ATPase
53
how is water regulated for cell volume
- passively regulated in response to changes in ions and osmolarity
54
porins
- like ion channels, but for transport of larger molecules
55
aquaporins
- membrane transporters specific to water molecules
56
ionic and osmotic challenges: marine environments (2)
- gain of salts
- loss of water
57
ionic and osmotic challenges: freshwater environments (2)
- loss of salts
- gain of water
58
ionic and osmotic challenges: terrestrial environments
- loss of water
59
ionic and osmotic challenges: movement between environments
- ability to alter homeostatic processes to meet demands of each environment
60
what are the strategies used to meet ionic challenges (4)
- ionoconformer
- ionoregulator
- osmoconformer
- osmoregulator
61
ionoconformers
- exert little control over ion profile within extracellular space
62
what type of animals are ionoconformers
- exclusively found in marine animals
63
ionoregulator
- control ion profile of extracellular space
64
what type of animals are ionoregulators
- most vertebrates
65
osmolarity of surroundings vs plasma: ionoconformer + osmoconformer (2)
- same osmolarity
- same ion concentrations/composition
66
osmolarity of surroundings vs plasma: ionoregulator + osmoconformer (2)
- same osmolarity
- different ion concentrations/composition
67
osmolarity of surroundings vs plasma: ionoregulator + osmoregulatory (2)
- different osmolarity
- different ion concentrations/composition
68
osmoregulator
- osmolarity is constant regardless of external environment
69
what types of animals are osmoregulators
- most vertebrates
70
osmoconformer
- internal and external osmolarity are similar
71
what types of animals are osmoregulators
- marine invertebrates
72
what terms describe the abilities of animals to cope with external salinities (2)
- stenohaline
- euryhaline
73
stenohaline
- can tolerate only narrow range of salinities
74
euryhaline
- can tolerate wide range of salinities
75
euryhaline osmoconformer
- osmolarity can decrease/increase in parallel with water until death
76
stenohaline osmoconformer
- dies after minimal osmotic disruptions
77
euryhaline osmoregulator
- maintains a nearly constant internal state throughout various major osmolarity changes, but eventually succumbs
78
stenohaline osmoregulator
- maintains internal osmolarity over narrow range of external osmolarities
