ch 19 Flashcards
sixth function of kidneys
Production of hormones: Name the hormones
Function 2 of kidneys
Regulation of osmolarity
urinary system
kidney and accessory structures
paired kidneys
modify and filter plasma into urine
paired ureters
pass urine from kidney to urinary bladder
urinary bladder
stores urine until micturition
Function 5
Excretion of wastes
Function 4
Homeostatic regulation of pH
Function 3
Maintenance of ion balance
function 1 of kidneys
Regulation of extracellular fluid volume and blood pressure
path of water droplet
bowmans capsule-> proximal convoluted tubule->descending loop of hence->thin ascending-> thick ascending-> distal convoluted -> collecting tube-> renal pelvis-> ureter-> bladder-> urethra
path of blood droplet
renal artery->afferent arteriole-> glomerulus->efferent arteriole-> vasa recta-> renal vein
vascular and tubular elements of nephron
see power point
3 processes of nephron
reabsorption, secretion, filtration
when is filtrate most concentrated
loop of henle
filtration fraction
% renal flow that filters into the tubule
renal corpuscle contains
barriers for filtration
where does filtration occur
renal corpuscle
what does the GCE contain for optimal absorption
fenestrated capillaries
glycocalyx
glomerular capillary endothelium
GCE
what is in the epithelium of bowman’s
podocytes
mesangial cells
net filtration pressure
renal blood flow and blood pressure
what 2 things does filtration coefficient depend on
surface areas of glomerular capillaries
permeability of filtration slits
is GFR constant or volatile
constant
INCREASED resistance in afferent arteriole
decreases GFR
INCREASED resistance in efferent arteriole
increases GFR
3 barriers from size and charge
radius<1.8nm filter freely
radius>3 nm do not filter(albumin)
1.8<radius<3 cations filtered anions not
3 pressures influence glomerular filtration
Capillary blood pressure
capillary colloid osmotic pressure
capsule fluid pressure
GFR
volume of fluid filtered per unit time
what influences GFR
Net filtration pressure
filtration coefficient
what is the myogenic response
Intrinsic ability of vascular smooth muscle to respond to pressure changes
(muscle can regulate blood flow)
what is myogenic response similar to?
autoregulatory response
what kind of control is tubuloglomerular feedback under
paracrine
what is the juxtaglomerular apparatus
macula densa and granular cells
macula densa
detect NaCl in the filtrate
granular cells
secrete enzyme renin
what influences GFR
hormones and autonomic neurons
how is GFR affected
changing arteriole resistance
altering filtration coefficient
reabsorption may be
active or passive
transepithelial transport
substances cross apical and basolateral membranes
paracellular pathway
substances pass through the cell-cell junction between two adjacent cells
active transport of Na+
creates electrical gradient
what follows Na+
anions to create osmotic gradient
why is Na+ important
establishes H2O gradient
secondary active transport of glucose
symport w/ Na+
what else can symport with Na
amino acids and organic molecules
passive reabsorption
urea can diffuse freely
endocytosis
plasma proteins
saturation
maximum rate of transport that occurs when all carriers are occupied by (are saturated with) substrate
transport maximum
the transport rate at saturation
renal threshold
the plasma concentration at which a substance first appears in the urine
excretion
filtration - reabsorption + secretion
clearance
a noninvasive way to measure GFR
clearance formula
excretion rate of X(mg/min)/ X
what is used to measure GFR
inulin and creatinine
creatinine
breakdown product of phosphocreatinine
where is inulin from
some plants like artichokes
inulin clearance
inulin excretion rate/[plasma inulin]
does composition of urine change after leaving collecting ducts
NOPE
micturition
process of urination
how many sphincters does the bladder have
internal and external
what sends signals in the spinal cord
stretch receptors in bladder walls
what induces bladder smooth muscle contraction
parasympathetic fibers
somatic neurons are inhibited to what
external sphincter
what is the primary route for excretion of ions and water
kidney
what products do lungs lose
H2O and HCO3
behavioral mechanisms for salt
thirst and craving
ECF osmolarity
affects cell volume
what is the rapid response to integrate fluid and electrolyte balance
respiratory and cardiovascular under neural control
what is the slow response to integrate fluid and electrolyte balance
kidney
how do we get water into the body
ingestion, normal metabolism, IV
how do we lose water
urine, feces, insensible water loss, pathological
low osmolarity
high water
high osmolarity
low water
diuresis
removing excess water in urine
where is water absorbed
descending loop of henle
thick ascending loop of henle
really thick cells, impermeable to water
where is fluid more dilute in loop of Henle
fluid leaving loop of Henle
cortical nephron
short loop of henle
peritubular capillaries
tiny blood vessels in the kidney
juxtamedullary nephron
long loop of henle
what percent of nephrons are Juxtamedullary
15%
bowman’s capsule
site of plasma filtration with the glomerulus
renal corpuscle parts
bowman’s capsule+glomerulus
collecting ducts
converge and drain into the renal pelvis
distal nephron
distal tubule and collecting ducts
filtration
Fluid from blood into the lumen of the nephron
filtrate
filtered plasma excreted unless absorbed
where does filtration occur
occurs at renal corpuscle
reabsorption
Materials in the filtrate are passed back into the blood
where does reabsorption occur
Occurs with peritubular capillaries
secretion
material from blood into lumen of tubule
where does secretion occur
occurs with peritubular capillaries
vasopressin
antidiuretic hormone
where does ADH act
collecting duct
where are ADH receptors
basolateral membrane
AQP2 channels
embedded on the apical membrane
graded effect
matches urine concentration to body’s need
when is more urine produced
at night
