Physiology Flashcards
what makes up a nephron
renal corpuscle + renal tubules
what makes up the renal corpsucle
afferent arteriole –> bowen’s capsule (squamous cells) –> efferent arteriole
components of the renal tubule
proximal convoluted –> loop Henle –> distal convoluted –> collecting duct
function of proximal convoluted tubule
70% sodium + water // almost all glucose and amino acids
structure + function loop of Henle
thick –> thin limb descending (water permeable) –> thin –> thick limb ascending (NaCl permeable)
what is the vasa recta
loops of blood vessels that follow loops of Henle to reabsorb to blood stream
function distal tubule
collects rest of Na via aldosterone
function collecting duct
water reabsorption secondary to ADH action
what marker is most accurate for eGFR
inulin
what marker is commonly used to determine eGFR
creatine (rise = creatine shows poor GFR)
what is clearance
rate at which plasma is cleared from a toxin - measure by creatine
what measures renal plasma flow
PAH
what measures renal plasma flow
PAH
what triggers release of ADH
low BP –> decreased atrial stretch
function ADH
increases permability to water in collecting duct –> reabsorbed
when is ANP released and what is the function
released from atrium when increased stretch –> excrete Na (+water) –> decreased volume
what controls rate of flow into nephrons
macula densa in distal tubule
what cells secrete renin
granular cells in JXA
what stimulates renin release
decreased pressure in afferent arteriole (reduced NaCl, reduced volume) // increased sympathetic activity (in response to low BP)
RAAS system overview
renin converts angiotensinogen –> angiotensin I // ACE converts angiotensin I –> II // angiotensin II causes adrenal cortex to release aldosterone
function aldosterone
increased reabsorption of Na + increased secretion of K
what stimulates release of erythropoeitn
cellular hypoxia (lack of 02 in blood)
what is osmolarity
concentration of osmotic particles in a solution
what % of body water is ICF vs ECF
ICF = 66% // ECF = 33%
components ECF
plasma, interstitial, transcellular
maintenance fluid requirements (water, electroclytes, glucose)
water 25-30 ml/kg/day // na,K,cl = 1 mmol/kg/ day // glucose = 50-100g/day
what does NICE recommend prescribing for routine maintenance only fluid in the first 24 hours
NaCl 0.18 in 4% water + 27 mmol/l K
risks of too much 0.9% saline
risk of hyperchlorine met acidosis
