lecture 2 - renal function and kidney disease Flashcards
what does the kidney do
produce urine
what does the ureter do
transports urine toward bladder
what does the bladder do
temporarily store urine
what does the urethra do
Let’s urine come out
what is excretion and elimination
removal of organic wastes products from body fluids e.g urea creatine uric acid
what is the main function of the kidney
maintain homeostasis for a number solutes and water
what ions need controlling of concentration in the kidneys
Na, K, Cl, Mg, Ca, H, HCO3
when can the kidney produce glucose
via gluconeogenesis during fasting
what is the kidney responsible for
elimination of many medication which changes the kidneys function which changes plasma concentration of these drugs
what’s the renal threshold for a substance
is the concentration of a substance in blood which is prevented from passing through the kidneys into the urine
what is the renal threshold for glucose
180mg/dL
what is tubular maximum
maximum capacity of the kidneys to absorb a particular substance (Tm)
what is the Tm for glucose
350mg/min
what does neutral balance refer to
the state in which dietary intake plus endogenous production equals excretion rate of the kidney
total body contents remains stable
what is positive balance
intake plus endogenous production >renal excretion rate, leading to increased total body content
what is negative balance
intake plus endogenous production <renal excretion rate, leading to decreased total body content
what are the key parts of the kidney
renal cortex
renal medulla
renal pelvis
renal pyramids
ureter
what are nephrons
the functional units of the kidney
where do the nephrons traverse
between the cortex and the medulla
what do the collecting ducts produce in the medulla
visible striations
what are the two classes of nephrons
cortical nephrons
juxtamedullary nephrons
what is the filtrate
blood plasma minus proteins
how is the filtrate produced
by glomerular filtration
what does the urine contain
metabolic wastes and unneeded substances
what are the three phases of urine formation
glomerular filtration
selective and passive reabsorption
secretion
where does glomerular filtration take place (specific)
through the semipermeable walls of the glomerular capillaries
how is the glomerular filtrate pushed through
by the driving hydrostatic pressure created by the arterial pressure
where does reabsorption occur
in the proximal and distal tubule
what happens to the filtrate during reabsorption
becomes highly concentrated due to water removal
what is reabsorbed by active transport?
low molecular weight constituents e.g glucose, organic/inorganic ions
what happens to substances during secretion
released into the urine in the kidney by active transport
e.g H+, K+, urea, creatinine and drugs
what is erythropoietin
polypeptide hormone that is formed by the kidney and liver
what does erythropoietin control
the differentiation of bone marrow cells
what stimulates release of erythropoietin
hypoxia (low pO2)
what does erythropoietin ensure the bone marrow cells do
they’re converted to erythrocytes, so their concentration in the blood increases
what are ways of investigating renal disease
physical exam, history
blood labs
urinalysis
renal biopsy
what should urine be?
sterile
clear
amber color
slightly acidic
characteristic odour
what is proteinuria
elevated protein in the urine
what could proteinuria be a risk factor for
deterioration of renal function, of cardiovascular morbidity and mortality
how is proteinuria detected
by a dipstick
only detects albumin
when is urine collected
early morning sample
quantitative measurement
what is pre renal proteinuria
excess formation of a low molecular weight protein that is freely filtered
How does glomerular proteinuria come about
damaged glomerular filtration barrier or increased hydrostatic pressure.
what is tubular proteinuria caused by
proteins with high conc in tubular cells aren’t be reabsorbed
what
