Renal Physiology Flashcards
what does urine volume and output depend on
glomerular filtration
tubular secretion
tubular reabsorption
what is filtered through the GFR
HCO3
Amino Acids
Creatinine
what should always be 100% reabsorbed back into the body
glucose
what can be used as a measure of the GFR due to it never being reabsorbed back into the body
creatinine
what hormone causes the reabsorption of water
ADH
what can the measure of creatinine give us
constant filtration rate
what should never be getting filtered through the GFR
RBCs
Albumin
what is secreted back into the urinary system along the descending tubule
urea
what hormone drives the reabsorption of Na Cl in the collecting tubule
aldosterone
what is secreted in the proximal and collecting tubules
H
what is secreted in the descending loop of henle
urea
what two analytes are the ‘basics/normals’ when analyzing kidney function
glucose
creatinine
what can be seen in the urine in cases of DM
acetoacetate
B-hydroxybutyrate
what 3 analytes might be seen in the urine in cases of RBC breakdown
bilirubin
hemoglobin dimers
myoglobin
what unnatural analyte can often be seen in horse urine if their diet is rich of it
Calcium
what is the concentration of a solution expressed as the total number of solute particle / kg solvent
osmolality
what can osmolality be used to ‘analyze’
expression of renal concentration ability
true or false:
resorption of water is dependent on osmotic gradients
true
what 3 analytes are used to calculate osmolality
Na
glucose
urea
what is the range for an ultrafiltrate
1.007-1.013
what would a USG within the range of 1.007-1.013 indicate
Isosthenuria
in what part of the tubules does an isosthenuric issue occur
proximal tubule
what is the range ofr an eusthenuric dog
> 1.030
what is the USG range for an eusthenuric cat
1.035
what is the USG range for an eusthenuric horse or cow
1.025
what is isosthenuria
state when urine osmolality = plasma osmolality
what USG range can be used to determine a hyposthenuria
<1.007
what can cause a hypersthenuric state
dehydration
what does hypersthenuria mean
excessive concentration of the urine
what can cause a hyposthenuria
too much water
(dilution of the concentration of urine )
what are the 6 main requirement for kidney to concentrate urine
functional nephrons (>33%)
concentration gradient in the medullary interstitium
ADH presence
Epithelium response to ADH
Aldosterone
Atrial naturetic peptide
what can trigger the release of ADH
hyperosmolality to increase the amount the H2O into circulation
what is the body system outcome from the release of ADH
constrict arterioles to increase BP
how does aldosterone become stimulated from the adrenals
due to the renin-angiotensin system
what is the outcome of the release of aldosterone
causes increased Na/Cl resorption
K excretion through distal tubules
what are the 3 things needed to produce concentrated urine
ADH
response to ADH
concentration gradient
what occurs when an hyposthenuric urine is produced
functional loop of henle (remove solutes but no water)
No ADH activity
which species naturally has the higher USG
cats
what is the normal USG range for a dog
1.001 - 1.060
what is the normal USG range for a cat
1.001-1080
what is the normal USG range for a horse
1.001 - 1.055
why is it important to recognize what is all included when using a refractometer to get a USG
total solutes will include proteins and glucose which can falsely increase the USG and needs correction
true or false:
a single ‘low’ USG may be normal if the animal is well hydrated
true
what can a repeatable lowered USG possibly signal before signs of azotemia
early renal disease
what analytes are increased in an azotemic state
urea
creatinine
in what part of the tubule tract is there damage or disfunction if the USG is increased
prerenal
in what disorder does polyuria occur because there are too few functional nephrons to respond to ADH
chronic renal failure
in what disorder does polyuria occur because the tubules are not responding to ADH / solute diuretic
post-obstructive diuresis
in what disorder does polyuria occur because theres a solute diuresis and a possible decrease in medullary tonicity
diabetes mellitus
in what disorder does polyuria occur because of decreased medullary tonicity, plasma osmolality and a decrease in release of ADH
psychogenic polydipsia
in what disorder does polydipsia occur because there is a lack of medullary tonicity caused by a lack of aldosterone
hypoadrenocorticism (Addison’s Disease)
in what disorder does polydipsia occur because of a lack of release of ADH
central diabetes insipidus
in what disorder does polydipsia occur because of an increase in cortisol which decreases the release of ADH
hyperadrenocorticism (Cushing’s)
