Renal Physiology I (Exam 5) Flashcards
1
Q
What other organ systems are involved in renal physiology?
A
- nervous system
- endocrine system
- musculoskeletal system
- cardiovascular system
- respiratory system
- digestive system
2
Q
____% of patients with renal insufficiency show oral signs and symptoms in soft and hard tissues.
A
90%
3
Q
___ & ____ of body fluid compartments are essential for homeostasis
A
constant volume and stable composition
4
Q
In order to maintain body fluid homeostasis _____ & _____ in must equal ___ & ____ out
A
water and electrolytes in must = water and electrolytes out
5
Q
Fluid distribution in the body influences:
A
electrolyte concentrations
6
Q
Electrolyte concentrations influence:
A
fluid distribution in the body
7
Q
What causes water gain?
A
- food and drink
- metabolism
8
Q
where can water be lossed?
A
- skin
- lungs
- urine
- feces
9
Q
Sweat and evaporation leading to water loss occur:
A
in the skin and lungs
10
Q
What is insensible water loss?
A
sweat and evaporation (can’t be controlled)
11
Q
Urine output is typically ____ but varies to create ____.
A
1.5 liters per day; balance
12
Q
How much insensible water loss occurs each day (70kg man)
A
0.9 liters per day
13
Q
How much water loss occurs through feces each day (70kg man)
A
0.1 liters/ day but varies
14
Q
What is the water gain due to food and drinks per day? (70 kg man)
A
2.2 liters per day
15
Q
How much water gain does metabolism bring in per day? (70kg man)
A
0.3 liters per day
16
Q
we want the extracellular fluid and intracellular fluid volumes to be:
A
constant
17
Q
Imbalances changes vascular and total body volumes:
A
Na+
18
Q
The primary determinant of extracellular fluid osmolarity and tonicity:
A
Na+
19
Q
Any changes in sodium will change water distribution in the body because:
A
Where the salt goes, water follows
20
Q
Imbalance alters cardiac and neural functions:
A
K+
21
Q
Potassium plays a great role in our:
A
excitable tissues
22
Q
Imbalance alters skeletal muscle, cardiac, neural function, and bone structure:
A
Ca++
23
Q
Necessary for synaptic transmission for skeletal and cardiac and smooth muscle contractions and one of the primary components making up the bone:
A
Ca++
24
Q
H+ comes in mainly from:
A
metabolism
25
Imbalances alter multiple systems:
H+
26
Imbalances in pH will alter multiple systems because pH impacts:
protein function
27
ECF = ___% of the body weight in kg
ICF= ___% of the body weight in kg
ECF= 20%
ICF= 40%
28
ECF breaks down into:
Plasma and Interstital fluid
29
ECF found within the blood vessels:
plasma
30
ECF found outside blood vessels and cells:
interstitial fluid
31
When we consume substances, those substances get added to the:
plasma
32
Once substances are consumed and added to the plasma, the capillaries immediately exchange that substance with the ____ through the capillary wall.
interstitial fluid
33
What fluid makes up 4-5% of our body weight in kg?
plasma
34
Our body is comprised of:
____ L of Intracellular fluid
_____ L of extracellular fluid
which breaks down into
_____ L of interstitial fluid
_____ L of plasma
28.0 intracellular fluid
14.0 extracellular fluid
11.0 interstitial fluid
3.0 plasma
35
Plasma and interstitial fluid are extremely similar in composition, the only thing that cannot move back and forth between these 2 compartments are:
proteins
36
The ____ is impermeable to proteins
capillary membrane
37
In a 70kg adult, the total body water volume is ____ liters making up ~ ____% body weight (kg)
42 liters; 60%
38
What is the barrier between the ECF and ICF?
plasma membrane
39
What ions are in a higher composition in the ECF?
1. Na+
2. Ca++
3. Cl-
4. HCO3-
5. glucose
40
What ions are in a higher composition in the ICF?
1. K+
2. Mg++
3. H+
4. Amino acids
41
Describe the amount of protein on the inside of the cell relative to the amount of protein on the outside of the cell:
A lot more protein inside than outside, but almost all protein on the outside is found in the PLASMA
42
Hypervolemia:
Hypovolemia:
Normovolemia/Euvolemia:
Hypervolemia= high blood volume
Hypovolemia= low blood volume
Normovolemia/euvolemia= normal amount of blood volume
43
Hypernatremia:
Hyponatremia:
Normonatremia/eunatremia:
high sodium levels in blood
Low sodium levels in blood
normal amount of sodium in blood
44
Hyperkalemia:
Hypokalemia:
Normo/eunatremia:
high potassium levels in blood
low potassium levels in blood
normal potassium levels in blood
45
Hypercalcemia:
Hypocalcemia:
Normo/eucalcemia:
high blood calcium
low blood calcium
normal blood calcium
46
because the capillary wall is a very leaky barrier, ____ & ___ mix rapidly excepting for ___.
plasma & interstitial fluid; proteins
47
What causes the mixing of the plasma and interstitial fluids?
hydrostatic and colloid osmotic pressure via capillary pores & bulk flow
48
Hydrostatic and colloid osmotic pressure via capillary pore is the main force governing:
bulk flow
49
movement of substance between plasma and interstitial fluid occurs via:
bulk flow
50
Fluid distribution between ICF & ECF is determined by ____ of ____ acting across the cell membrane
osmotic effect of small solutes
51
Water will move down a free water gradient and this free water gradient is determined by the concentration of:
impermeable substances
52
What adds up to equal ~90% of total ECF osmolarity?
Na+ and Cl- (and other anions)
53
Anytime we have a change in ECF osmolarity, what effect will this have on tonicity? Why?
we will also have a change in tonicity; because these substances are impermeable (Na + Cl- and other anions)
54
What adds up to equal ~90% of total ICF osmolarity?
K+ and other ions
55
The cell membrane may also be referred to as:
plasma membrane
56
Describe the cell membranes permeability to water:
high permeability to H20 dependent of location of cell in body
57
Describe the cell membrane permeability to Na+, Cl- & other electrolytes:
relatively impermeably to small solutes such as these
58
Why would changes in the concentration of Na+, Cl- & other electrolytes change the tonicity and water distribution in the body?
because the cell membrane is relatively impermeable to these small solutes
59
Cell volume is at the mercy of:
ECF tonicity
60
If a cell is placed in a hypertonic bathing solution, what will happen to the volume of the cell?
cell will shrink
61
The concentration of impermeable substances in the bathing solution is greater than the the concentration of impermeable substances inside the cell:
How would you describe this bathing solution?
Hypertonic
62
If a cell is placed in an isotonic bathing solution, what will happen to the volume of the cell?
No change in cell volume
63
Concentration of impermeable substances in the bathing solution is equal to the concentration of impermeable substances inside the cell:
How would you describe this bathing solution?
isotonic
64
Is their movement of water between the bathing solution and cell in an isotonic situation?
Yes there is movement but no NET movement
65
The concentration of impermeable substances in the bathing solution is less than the the concentration of impermeable substances inside the cell:
How would you describe this bathing solution?
Hypotonic
66
If a cell is placed in a hypotonic bathing solution, what will happen to the volume of the cell?
Cell swells
67
Composition and volume of ECF change determine composition and volume of:
fluid replacement
68
_____ & ____ are constantly being challenged in the body
ECF osmolarity & volume
69
Why can the skin being burned cause such extensive body water loss?
because the skin is a major waterproofing organ
70
If a ____ solution is added into a normal individual, the ECF volume is increased, the ECF osmolarity is unchanged, and the ICF osmolarity and volume are both unchanged:
Isotonic
71
If a ____ solution is added into a normal individual, the volume and osmolarity will expand creating an osmotic gradient for water to move out of the cells into the ECF further expanding, and reducing the volume in the ICF, raising the ICF osmolarity:
Hypertonic
72
If a ____ solution is added into a normal individual, we will lower the ECF osmolarity and raise the ECF volume. As the osmolarity is lowered, this creates a gradient to cause water to move to the ICF via osmosis:
hypotonic
73
The kidneys regulate body fluid and composition by controlling:
ECF volume and composition
74
Too much water in tissues:
edema
75
What are the two types of edema?
intracellular and extracellular edema
76
____ edema is much more common
extracellular
77
What are the 3 causes of intracellular edema?
1. hyponatremia
2. Decreased metabolism (blood flow)
3. Inflammation (infection & burns)
78
____ is the primary determinant of ECF osmolarity and tonicity
Na+
79
Explain why hyponatremia can cause intracellular edema:
sodium is in a higher concentration in the ECF, if you don't have enough sodium, you will lower the osmolarity of the ECF causing water to rush into the cells causing intracellular edema
80
Decreased metabolism (blood flow) that causes intracellular edema is due to:
Na+/K+ pump failure
81
Explain how Na+/K+ pump failure leading to decreased blood flow will lead to intracellular edema:
The Na+/K+ ATPase pumps potassium into the cell and sodium out of the cell. If this pump is inhibited, it will cause more sodium to build up in the cell and water will flow into the cell because of this causing intracellular edema
82
Explain how inflammation (infection & burns) can lead to intracellular edema:
inflammation causes increased membrane permeability and leakage which causes lots of extra ions to build up inside the cell, and water would follow them in.
83
What do we look at when determining water balance?
sodium
84
____ is the most important cation in the body
sodium
85
Na+ salts make up greater than _____ in the ECF
90% of osmotically active solute in ECF
86
Na+ (and hence ECF volume) is highly:
regulated
87
Too little ECF leads to: (3)
1. volume contraction
2. hypotension
3. organ hypoperfusion
88
Too much ECF leads to: (4)
1. edema
2. ascites
3. pleural effusions
4. hypertension
89
In hyponatremia, the concentration of sodium in the ____ is below normal.
Give value:
ECF; Less than 142 mOsm/L
90
In hyponatremia:
Na+ input _____ Na+ output
H2O input ____ H2O output
Na+ Input < Na+ output
H2O input > H2O output
91
Na+ Input < Na+ output
H2O input > H2O output
This leads to:
drop in Na+ concentration (hyponatremia)
92
What are the 3 types (causes) of hyponatremia?
1. Hyponatremia-dehydration
2. Hyponatremia-overhydration
3. Hyponatremia-low solute intake
93
What is the cause of hyponatremia dehydration?
- Caused by _____.
- Which is caused by:
- Increased NaCl loss
- committing, diarrhea, renal disease, diuretics, Addison's deficiency
94
How does Addison's disease cause increased NaCl loss? What does this ultimately cause?
Someone with Addisons disease produces insufficient levels of cortisol, but also aldosterone.
Aldosterone stimulates sodium reabsorption in the kidneys, so not enough aldosterone = not enough sodium brought back into the body
95
What hormone involved in Addison's disease can cause increased loss of NaCl?
Aldosterone
96
What is the function of aldosterone?
stimulates sodium reabsorption in the kidneys (brings sodium back into the body)
97
Most common electrolyte disorder in clinical practice:
hyponatremia
98
Hyponatremia may account for ____% of hospitalized patients
20-25%
99
Hyponatremia-overhydration is caused by _____ which is caused by ____.
Excess H2O retention; Inappropriate ADH secretion & H2O toxicity
100
What is the function of ADH?
Causes water retention
101
How might too much ADH cause hyponatremia-overhydration?
Too much ADH causes too much water to be retained which dilutes the ECF leading to hyponatremia
102
H2O toxicity is caused by:
drinking too much water too quickly
103
Hyponatremia-low solute intake is caused by ____ which is caused by ___.
Decreased NaCl intake; extreme diets
104
If someone has hyponatremia due to NaCl loss this would be considered:
hyponatremia-dehydration
105
If someone has hyponatremia due to excess H2O retention, this would be considered:
Hyponatremia-overhydration
106
If someone has hyponatremia due to decreased NaCl coming in this would be considered:
Hyponatremia-low solute intake
107
The main consequence of hyponatremia is:
cell swelling
108
Gradual decrease in the concentration of Na+ in the ECF over months:
chronic hyponatremia
109
A gradual decrease in the concentration of Na+ in the ECF over months stimulates:
transport of Na+,K+, and organic solutes out of cells
110
A gradual decrease in the concentration of Na+ in the ECF over months stimulates transport of Na+,K+, and organic solutes out of cells which causes:
water diffusion out of the cells
111
With chronic hyponatremia, the brain swelling is attenuated by:
transport of solutes from the cells
112
Why must we correct the concentration of Na+ in the ECF slowly when treating chronic hyponatremia?
to avoid osmotic demyelination
113
What is osmotic demyelination?
Rapid loss of H2O from neurons cause axons in the CNS to become demyelinated
114
Acute hyponatremia may be caused by:
water toxicity
115
A rapid decrease in the concentration of Na+ in the ECF:
acute hyponatremia
116
What are the causes of acute hyponatremia? (2)
1. loss of Na+
2. Excessive H2O
117
Where is the movement of water in acute hyponatremia?
Into the cells
118
What occurs with the brain in acute hyponatremia?
swelling of brain tissue
119
What type of hyponatremia is characteristic with a marathon runner?
acute hyponatremia
120
Increased interstitial fluid volume would cause:
extracellular edema
121
What are the causes of increased interstitial fluid volume leading to extracellular edema?
1. increased capillary filtration
2. failure of lymphatics to return interstitial fluid to circulation (lymphedema)
122
Failure of lymphatics to return interstitial fluid to circulation is called ____ and is a common cause of ____.
lymphedema; extracellular edema
123
Increased capillary filtration causing extracellular edema is most commonly associated with:
congestive heart failure
124
~3 liters of fluid is filtered out of the systemic capillaries everyday and that fluid gets returned by:
lymphatics
125
What are the two main determinants of bulk flow?
Capillary pressure (Pc) & Plasma colloid osmotic pressure (Pi-c)
126
What are the filtration forces?
Capillary pressure (Pc) & Interstitial colloid osmotic pressure (Pi-isf)
127
What re the absorptive forces?
Plasma colloid osmotic pressure (Pi-c) & Interstitial hydrostatic fluid pressure (Pisf)
128
What determinant of capillary filtration is due to blood pressure?
Capillary pressure (Pc)
129
What determinant of capillary filtration is due to impermeable plasma proteins?
Plasma Colloid Osmotic pressure (Pi-c)
130
What are the minor determinants for bulk flow?
Interstitial fluid hydrostatic pressure (Pisf) & Interstitial colloid osmotic pressure (Pi-isf)
131
The difference between the filtration pressure and the absorptive pressures:
Filtration rate
132
If the filtration rate is positive this means:
overall net filtration out of capillaries
133
If the filtration rate is negative this means:
overall net absorption into the capillaries
134
Equation for filtration rate:
Filtration rate= Kf ((Pc + Pi-if) - (Pif + Pi-c))
135
Kf is a constant for ____. It is a fxn of the ___ & _____
membrane permeability; SA & membrane permeability
136
List the 3 common causes for extracellular edema:
1. increased capillary permeability
2. increased capillary hydrostatic pressure
3. decreased capillary osmotic pressure
137
What are some reasons the capillary may have increased permeability?
1. inflammation (infection & immune reactions)
2. Burns
3. Ischemia
138
Anything that increases capillary permeability will allow more water and maybe even more proteins to escape into the ____.
If proteins except into the ___ this raises the ___ of the ____, drawing more water out and leading to extracellular edema
interstitial fluid
interstitial fluid; colloid osmotic pressure of the interstitial fluid
139
Increased capillary hydrostatic pressure may be caused by: (2)
1. heart failure
2. renal disease
140
Left heart failure would cause edema _____; versus generalized heart failure would cause edema ____.
left: edema in pulmonary circulation
generalized: edema all over body
141
Decreased capillary colloid osmotic pressure can be caused by (2):
1. renal loss (nephrotic syndrome)
2. Live disease
142
Liver disease causes decreased capillary colloid osmotic pressure by:
lack of production of plasma proteins
143
Renal loss (nephrotic syndrome) causes deceased capillary colloid osmotic pressure by:
more loss of proteins in the urine with decreases the colloid osmotic pressure
144
Edema by another name:
effusions
145
build up of fluid in potential spaces:
effusions
146
Potential spaces that effusions may occur in: (4)
1. pleural cavity
2. pericardial cavity
3. peritoneal cavity
4. synovial cavities
147
Lining membranes are:
highly permeable
148
____ is important for clearing fluid and proteins
lymphatic drainage
149
Build up of fluid in the peritoneal space:
ascites
150
What are the changes in the following variables after giving 2.0 liters of water i.v.?
1. ECF Volume:
2. ECF Osmolarity:
3. ICF Volume:
4. ICF Osmolarity:
1. increase
2. decrease
3. increase
4. decrease
151
152
through the skin, lungs, urine, and feces
