Renal Physiology 1 Flashcards
What separates hte intracellular and extracellur fluid?
cell membrane
bilipid layer
proteins
cell membrane
Cell membrane component taht controls the entry of fluid and electrolyte
cell membrane
bilipid layer
proteins
bilipid layer
Cell membrane component taht acts as channels or transporters
cell membrane
bilipid layer
proteins
proteins
part of fluid compartment that :
- in between cells
- fluid in blood vessels
- in specific places like CSF, synovial joint , plueral
Intracellular Extracellular Intravascular Interstitila Trans cellular
Interstitial
Intravascular
Trans cellular
All other blood vessels have no movement of fluid except at the capillaries. Why?
Movement of fluid is only at the level of capillary, because it has at least 3 layers
Movement of fluid and other electrolytes are limited to capillaries where blood exchange happens by the process of diffusion
Capillaries are also known as interstitial exchanger
Capillaries also have pores and gaps which determine what can pass and what can’t
Capillaries also have pores and gaps which determine what can pass and what can’t
Movement of fluid is only at the level of capillary, because it has a single layer only, in contrast with other blood vessels which have at least 3 layers
Movement of fluid and other electrolytes are limited to capillaries where blood exchange happens by the process of diffusion
Capillaries are also known as exchange vessels
To measure total body water:
= use substance that will stay in the blood vessel and will not go out through the pores of the capillary (radioactive albumin) or a substance that binds proteins (Evans blue dye)
= use radioactive water or heavy water
= plasma/ 1 – hematocrit
= Uses inulin and radioactive Na or Cl
= causes differential distribution of ions due to the Na-K pump which makes the sodium goes out, because where the Na goes H2O will follow
= material that will pass through the blood compartment into the interstitial space but not pass through the cell membrane
Extracellular volume Inulin Radioactive Na or Cl Intracellular volume = TBW-ECF ; it can only be estimated Plasma Total blood volume Total body water
To measure total body water:
Total body water = use radioactive water or heavy water
Extracellular volume
o use inulin – material that will pass through the blood compartment into the interstitial space but not pass through the cell membrane
o Radioactive Na or Cl – causes differential distribution of ions due to the Na-K pump which makes the sodium goes out, because where the Na goes H2O will follow
Intracellular volume = TBW-ECF ; it can only be estimated
Plasma = use substance that will stay in the blood vessel and will not go out through the pores of the capillary (radioactive albumin) or a substance that binds proteins (Evans blue dye)
Total blood volume = plasma/ 1 – hematocrit
Movement of fluid across vascular endothelium and cell membrane
Cell membrane Na+K+ATPAse ____
___ is determined by Na+
Most cells are permeable to water which moves by ___
Osmolarity of ___
K+ intracellular Na+ extracellular intracellular fluid ECF volume osmosis
Movement of fluid across vascular endothelium and cell membrane
Cell membrane Na+K+ATPAse = K+ intracellular and Na+ extracellular
ECF volume is determined by Na+
Most cells are permeable to water which moves by osmosis
Osmolarity of intracellular fluid
- ____determines what’s in intravascular space vs.
interstitial space. - The movement of Na and Cl across the capillary is
based on ____ - H2O will also move via ___
- ____ that attracts H2O and depends on solute that is not
permeable or stays in particular compartment
diffusion
osmotic pressure
osmosis
capillary
Capillary determines what’s in intravascular space vs.
interstitial space. The movement of Na and Cl across the capillary is
based on diffusion; H2O will also move via osmosis (osmotic
pressure that attracts H2O and depends on solute that is not
permeable or stays in particular compartment).
Main cation in the plasma and interstitial fluid is
___, while in the intracellular fluid it’s ___.
Na
K
Main cation in the plasma and interstitial fluid is Na, while in the intracellular fluid it’s K.
o specific material inside cells that will never pass out
o proteins in plasma that will never get into the interstitium because they are very large and cannot pass through the pores
o except when pores are made large (histamine and
bradykinin -> ___), in which case the proteins can enter and eventually will cause ___
o There should be electrolyte neutrality; the total number of
positive and negative ions on each side of the compartment
must be equal because of ____
edema Gibbs Donnan equilibrium Albumin and plasma proteins Intracellular proteins increases permeability
Intracellular proteins
o specific material inside cells that will never pass out
Albumin and plasma proteins
o proteins in plasma that will never get into the
interstitium because they are very large and cannot
pass through the pores
o except when pores are made large (histamine and
bradykinin -> increases permeability), in which case
the proteins can enter and eventually will cause
edema
There should be electrolyte neutrality; the total number of
positive and negative ions on each side of the compartment
must be equal because of Gibbs Donnan equilibrium.
- cell will not shrink nor swell
- cell will swell
- cell will shrink
- higher concentration of impermeant solutes than cell
- lower concentration of impermeant solutes
- same concentration of impermeant solutes between cell and the solution
- ## e.g. 0.9% NaCl; 5% glucose solution
Hypotonic solution
o lower concentration of impermeant solutes (
What if you give hypotonic solution?
ECF volume
ICF volume
total volume
osmolality
increase
decrease
Q: What if you give hypotonic solution?
↑ ECF volume ↑ ICF volume = ↑ total volume
↓ osmolality
What happens to the ECF volume and osmolality and ICF volume
and osmolality when you give isotonic NaCl to a patient?
Osmolality will increase
total volume would decrease (due to decrease in ECF volume)
It will not go intracellularly so ICF volume would not
change unless the person is dehydrated
What happens to the ECF volume and osmolality and ICF volume
and osmolality when you give isotonic NaCl to a patient?
Osmolality will not change
total volume would increase (due to ↑ECF volume)
It will not go intracellularly so ICF volume would not
change unless the person is dehydrated
Production and secretion of hormones
- triggered by hypoxia (↓ O2)
- released when there is low blood flow to kidneys
- RAAS (see below) – for long term regulation of BP
- regulation of Ca2+
- Hydroxylation reactions (at position 1: kidney, at position 25: liver)
o Erythropoietin
o 1,25 hydroxyvitamin D3 (calcitriol)
o Renin
Production and secretion of hormones
o Erythropoietin – triggered by hypoxia (↓ O2)
o Renin
released when there is low blood flow to kidneys
RAAS (see below) – for long term regulation of
BP
o 1,25 hydroxyvitamin D3 (calcitriol)
regulation of Ca2+
Hydroxylation reactions (at position 1: kidney, at
position 25: liver)
MAIN FUNCTION of renal system
- maintaining balance
- Regulation of body fluid volume and osmolality –it can conserve
or regulate ions and electrolytes. - Regulation of electrolyte balance
- Excretion of waste products (urea, ammonia, drugs, toxins)
- Regulation of acid-base balance
Renal system
MAIN FUNCTION: Maintaining balance
Regulation of body fluid volume and osmolality –it can conserve
or regulate ions and electrolytes.
Regulation of electrolyte balance
Excretion of waste products (urea, ammonia, drugs, toxins)
Regulation of acid-base balance
Renin Angiotensin-Aldosterone System.
A decrease in BP will result to a decreased blood flow (GFR) to the kidneys, stimulating the macula densa (sensitive to Na concentration) of the DCT. The juxtaglomerular cells will release renin.
Renin catalyzes the conversion of angiotensinogen to angiotensin I. Angiotensin I will: a) vasoconstrict blood vessels increasing the TPR resulting to an increase in BP (corrected) b) be converted to angiotensin II by ACE (Angiotensin converting enzyme) which is from the lungs. Angiotensin II is the more potent vasoconstrictor. It will also stimulate the adrenal cortex to secrete aldosterone. Aldosterone promotes Na reabsorption thereby increasing the water retention resulting to an increased BP.
Renin Angiotensin-Aldosterone System. A decrease in BP will result to a decreased blood flow (GFR) to the kidneys, stimulating the macula densa (sensitive to Na concentration) of the DCT. The juxtaglomerular cells will release renin. Renin catalyzes the conversion of angiotensinogen to angiotensin I. Angiotensin I will: a) vasoconstrict blood vessels increasing the TPR resulting to an increase in BP (corrected) b) be converted to angiotensin II by ACE (Angiotensin converting enzyme) which is from the lungs. Angiotensin II is the more potent vasoconstrictor. It will also stimulate the adrenal cortex to secrete aldosterone. Aldosterone promotes Na reabsorption thereby increasing the water retention resulting to an increased BP.
Blood Flow to the kidneys = ___ in resting person
- 0 L/min
- 25 L/min
- 0 L/min
- 5 L/min
Blood Flow to the kidneys= 1.25L/min in resting person
The osmolality of the body is maintained at approximately ____
o except in the medulla which is hyperosmolar (responsible for conservation of water)
100 mOsm 200 mOsm 300 mOsm 400 mOsm 500 mOsm
The osmolality of the body is maintained at approximately 300 mOsm
o except in the medulla which is hyperosmolar (responsible for conservation of water)
