Renal Physiology Overview Flashcards
3 components of glomerular filtration wall from inside to outside
visceral epithelial cells- podocytes
glomerular basement membrane
squamous epithelial cells- parietal epithelial cells
glomerular filtration barrier is composed of: (3)
capillary endothelium
podocytes
basement membrane
glucose renal threshold represents (160-180 mg/dL)
maximum range of glucose reabsorption in renal tubules
aldosterone is involved in _____ reabsorption and is released by the _____ of the adrenal cortex
sodium reabsorption
zona glomerulosa
order of cast degradation
cellular > granular > waxy
green brown urine would MC co-exist with physical exam finding of:
murphy’s sign (cholecystitis, gallbladder/bile duct destruction)
level of the kidneys
T11-L3 retroperitoneally
layers of adrenal gland
capsule, adrenal cortex, adrenal medulla
or specifically capsule, zona glomerolusa, zona fasciculata, zona reticularis, adrenal medulla
main functional unit of kidney
nephrons
location and # of nephrons
adrenal cortex and medulla, approx 1 million or more in each kidney
fxn of glomerulus
blood filtration
part of nephron that fxn is reabsorption and secretion
proximal convoluted tubules
loop of henele
distal convoluted tubules
______ nephrons are located mostly within cortex and have ____ length of loop of Henle
cortical
short
_____ nephrons are located deep in medulla and have ____ length of loop of Henle
juxtamedullary
long
blood passes through kidney at what rate
~ 1200 ml/min or 600 ml/min/kidney
Afferent arterioles form the capillary tuft called _____
glomerulus
Efferent arterioles form ______
peritubular capillaries (vasa recta)
_____ surrounds each glomerulus
bowman capsule
outer layer of bowman’s capsule is composed of ________, which lays on top thin ______
squamous epithelium (parietal epithelium) basal lamina (type IV collagen)
inside layer of bowman’s capsule is composed of _____
podocytes (visceral epithelial cells)
____ is key indicator of kidney function and is used to monitor kidney disease
glomerular filtration rate (GFR)
normal GFR is _____; older people have _____ rate
90-120 ml/min
lower (GFR decreases with age)
GFR tests how much kidneys are filtering ______
creatinine
waste which is a breakdown product of creatine phosphate in muscles
creatinine
_____ appears in the urine when plasma concentration exceeds 160 to 180 mg/dl
glucose
secretion of ____ & ____ occurs in PROXIMAL TUBULES
uric acid organic acids (antibiotics)
REABSORPTION of K, NaCl, H2O, AA, glucose, HCO3- occurs in ________ NO CREATININE REABSORPTION
proximal tubules
the only function of loop of henle is _____
reabsorption (NEVER secretion)
(4) things reabsorbed by loop of henle
H20
NaCl
Ca
Mg
____ limb of loop of henle is permeable to water
descending
____ limb of loop of henle is impermeable to water but, ________ of solute WITHOUT water occurs
ascending
active reabsorption
fluid leaving loop of henle has ____ osmolality than plasma because _____
lower
lost NaCl
during tubular reabsorption, hydrogen ion are exchanged for the sodium ions in _____
sodium bicarbonate
___% of glomerular filtrate is reabsorbed by the time it reaches the DISTAL tubule, ____ is also reabsorbed
90%
urea
(2) things that are ONLY reabsorbed in PROXIMAL tubules
glucose
AA
_____ accounts for removal of unneeded foreign waste substances that are not filtered by the glomerulus including toxins and medications
tubular secretion
____ ions are produced as waste from metabolism and generally secreted in kidney, _____ can also be secreted, but more often is is REABSORBED to help maintain __
hydrogen
bicarbonate
pH
main fxns of distal and collecting tubules (4)
- adjustment of pH, osmolality and electrolytes
- regulation of substances still present in filtrate
- secretion of potassium, ammonia and hydrogen ions
- reabsorption of sodium and bicarbonate
region in nephron that is important for regulating BP, body fluids and electrolytes; regulates the function of EACH NEPHRON
juxtaglomerular apparatus (JGA)
(3) components of juxtaglomerular apparatus
macula densa of distal convoluted tubule
smooth muscle cells of afferent arterioles (juxtaglomerular cells)
mesangial cells
mesangial cells secrete
erythropoietin
RENIN is an _____ that is secreted by _______ ; secreted and reacts with precursor _______ to be converted to ______ in blood
enzyme
juxtaglomerular cells
angiotensinogen
angiotensin I
angiotensin I passes through _____ where enzyme ______ changes it to _______
lungs
angiotensin converting enzyme
angiotensin II
angiotensin II results in:
systemic vasoconstriction (including afferent and efferent arterioles)
angiotensin II triggers release of _______ and ______
aldosterone (from adrenal glands)
antidiuretic hormone aka vasopressin (from pituitary gland)
aldosterone is secreted by _______ and fxn to _________, which in turn INCREASES blood volume as water follows salt –> ________
adrenal cortex (zona glomerulosa)
increase blood sodium reabsorption (in distal tubules)
RAISES BP
antidiuretic (vasopressin) hormone is synthesized in _____ and stored/released in ____
hypothalamus
vesicles in posterior pituitary gland
Diabetes Insipidus may be caused by (2)
insufficient ADH
abnormal kidney response to ADH (nephrogenic DI)
excessive release of ADH
syndrome of inappropriate ADH Secretion (SIADH- syndrome)
SIADH- syndrome is caused by _______ 80% of the time
small cell lung carcinoma
SIADH- syndrome results in: (5)
high plasma volume low serum osmolarity low plasma sodium (hyponatremia) high urine osmolarity higher than normal urine sodium
ADH causes _____ water retention without ______ fluid volume expansion or ______ or _____
increased
extracellular fluid volume expansion
edema
HTN
when hyponatremia is severe, may cause _____ symptoms to be more prominent
cerebral edema (irritability, confusion, seizures and coma)
cells that produce and secrete renin
juxtaglomerular cells
