Renal Flashcards
kidney function
-excrete excess/harmful substances
-maintain constant volume and composition of fluid
-endocrine function- secrete renin, erythropoietin (stimulate RBC production), and 1,25-dihydroxycholescalciferol (vitamin D for calcium homeostasis)
medulla
-outer medulla- has outer and inner stripe
-inner medulla
-papilla- innermost tip of inner medulla -> minor and major calyces
nephron
-afferent arterioles -> filter blood in glomerulus -> ultrafiltration -> efferent arterioles -> peritubular capillaries
-function unit of the kidney
-efferent arteriole then loops down along the loop of henle (becomes the vasa recta) -> allows for reabsorption from loop to vasa recta -> goes into venous system
-afferent and efferent arteriole before and after allow for regulation
filtration
-we dont filter out proteins, RBC, glucose
-any glucose that does filter gets reabsorbed in a healthy individual
diabetes
-transporters are saturated
-excrete glucose
-with glucose comes water
-diabetics c/o thirst and frequent urination
parts of nephron
-glomerulus- filters out plasma
-proximal convoluted tubule- reabsorption
-loop on henle- filtrate/concentrated urine
-distal convoluted tubule- acid base regulation and water reabsorption
-collecting duct- absorbs water, concentrates urine
-ureter
-each part has different epithelial cell based on its function -> each part has different transport membranes and permeability
juxtamedullary nephron
-peritubular capillaries have specialization -> VASA RECTA -> follow same course as loop of henle
-vasa recta reabsorbs from loop of henle -> goes into venous
-vasa recta serve as osmotic exchanges for production of concentrated urine
-longer loop on henle
-filters a lot more blood
-greater concentrating ability
-removes water to concentrate urine
-higher GFR
superficial nephrons
-peritubular capillaries branch off efferent arterioles and deliver nutrients to epithelial cells
-peritubular capillaries also serve as blood supply for reabsorption and secretion
-reabsorption and secretion
total body water
-total body water is inversely proportional to body fat
-60% total body water/weight -> ICF (40%) and ECF (20%)
-1/3- ECF -> Na, Cl, HCO3-
-2/3- ICF -> K, Mg, anions (Proteins and organic phosphates)
-ECF is made up of interstitial fluid (around cells 3/4) and plasma (blood 1/4)
-plasma and interstitial fluid is separated by capillary wall
gibbs-donnan effect
-small differences in concentrations of small cation and anions between interstitial fluid and plasma
-plasma contains slightly negative plasma proteins -> slight retention of Na and slight repellant of Cl -> goes into interstitial fluid
dilution method
-use substance that will only stay in
transcellular compartment
-small
-CSF, pleural, peritoneal, digestive fluids
plasma
-aqueous blood
-55% of blood
-hematocrit- % of blood volume occupied by RBCs
-plasma protein- 7%
-93%- plasma water
osmolarity
-from ICF to ECF (vice versa) based on osmolarity
-disturbances- diarrhea, dehydration, adrenal insufficiency, infusion of isotonic saline, NaCl intake, syndrome of inappropriate antidiuretic hormone (SIADH)
-hyperosmolic - water shifts in
-osmotically active solutes- depends on Na, Cl, and HCO3-
-plasma osmolarity determined by Na, glucose, BUN
-plasma osmolarity is the one we can alter - give fluids
-steady state- all osmolarity is equal
volume contraction and volume expansion
-volume contraction- decrease in ECF volume
-volume expansion- increase in ECF volume
-influenced by hypo, hyper, iso osmotic state
isosmotic disturbance
-diarrhea
-isosmotic change
-losing water, Na, Cl
-volume we are losing is isosmotic to plasma
-osmolarity between ECF and ICF stay the same
-losing NaCl and water from ECF at the same proportion of ICF*
-ECF volume decreases*
-ICF volume remains the same
-tx- infusion isotonic fluid into plasma -> increase ECF volume without changing osmolarity
hyperosmotic volume contraction
-dehydration
-not drinking water, sweating
-1. losing pure water from ECF
-2. ECF higher in osmolarity (hyperosmotic) -> sucks fluid out of ICF
-3. reduction of volume is both ICF and ECF in order to maintain a equal osmolarity between each
-each reduce volume and increase osmolarity
-hyperosmotic volume contraction!!
hypoosmotic volume contraction
-adrenal insufficiency
-not enough aldosterone (holds onto sodium)
-1. loss of Na in ECF
-2. ECF becomes hypoosmotic
-3. water sucked into ICF from ECF (bc ICF is hyperosmotic to ECF)
-overall- ECF decreases volume and ICF increases volume AND both reduce osmolarity
isotonic volume expansion
-infusion of isotonic NaCl
-adding into ECF straight into plasma
-increases ECF volume
-no water shift bc substance added is the same osmolarity
hyperosmolar volume expansion
-high salt diet- increase NaCl intake
-1. increases the osmolarity of ECF (hyperosmotic)
-2. ECF sucks fluid from ICF
-overall both compartments increase osmolarity and ECF increases volume and ICF loses volume