renal function Flashcards
what are the functions of the kidney?
- maintain a stable internal environment (homeostasis)
- endocrine functions (secrete hormones)
- gluconeogenesis
- form urine
what is maintained in homeostasis within the functions of the kidney?
solutes + water
acids + base
nutrients
waste
what hormones are secreted within the functions of the kidney?
renin
EPO
vitamin d3 (calcium metabolism)
what is gluconeogensis?
create glucose from things such as amino acids
what is contained in the kidney function of forming urine?
filtration
reabsorption
secretion
storage
removal (waste)
what force favors filtration?
capillary hydrostatic pressure
BHP, CHP
how much do the kidneys filter in a healthy individual?
120mL/minute
in a healthy individual, how much of the content that os filtered is reabsorbed and returned to the body by the tubules?
99%
what effect does vasoconstriction of the afferent renal arteriole have on GFR and body fluid conservation?
GFR decreases
BFC increases
what effect does vasoconstriction of the efferent renal arteriole have on GFR and body fluid conservation?
GFR increases
BFC decreases
what effect does severe malnutrition (without dehydration) have on GFR and body fluid conservation?
GFR decreases
BFC increases
what effect does obstruction to the outflow of urine have on GFR and body fluid conservation?
GFR decreases
BFC increases
what does the PCT reabsorb?
glucose
sodium
H2O
what does the DCT reabsorb?
H2O directly stimulated by ADH
Which hormone leads to increased reabsorption of Na?
aldosterone
How does tubular secretion occur in the nephron?
-Movement of substances from the peritubular capillaries to the tubular lumen
-Proximal tubule and CD receive secretions of H +
-Distal tubule and CD receive secretions of K + (aldosterone)
what ways do we access renal function?
urine output
plasma creatine-PCR
blood urea nitrogen-BUN
How do PCR levels help to access renal function?
Creatinine is a product of muscle metabolism (breakdown of macromolecules), and is filtered by the glomerulus
How do BUN levels help to access renal function?
Urea is filtered by the glomerulus
what is urea?
The molecule urea is formed from protein and amino acid degradation
when GFR is low, what happens to PCR and BUN?
they are high
when protein malnuturton occurs, what happens to PCR and BUN?
they are decreased INITIALLY
how do we classify kidney disfunction?
acute or chronic
reversible or irreversible
how is considered decreased renal reserve?
less than 25% kidney function
-require increased demands of kidneys