renal - lecture 1 Flashcards
describe 4 functions of kidney
regulation of water, inorganic ion balance and acid base balance = sodium, potassium, hydrogen, chloride, bicarbonate ion, water
removal of metabolic waste products and their excretion in urine
removal of foreign chemicals from blood and excretion in urine - drugs like antibiotics, some metabolized in liver
production of hormones/enzymes
name and describe 3 hormones/enzymes kidney produces
epo = most important, hormone that controls erythrocyte production in bone marrow
renin = enzyme that controls formation of angiotensin and influences bp and sodium balance
1,25-dihydroxy vit d = active vitamine that influences calcium balance - needs to be hydroxylated at 1 in kidney
describe gross anatomy of kidney
paired organs = 150g each
behind peritoneum on either side of vertebral column against posterior abdominal wall = small of back
renal = pertaining to kidneys
name parts of kidney
renal cortex
renal medulla = pyramid shaped
renal pelvis = cortex and medulla make urine and urine sits in renal pelvis and then goes to ureter to bladder
ureter = connects kidney to bladder
urethra = bladder to outside of body
describe blood supply of kidneys
renal artery = direct branch of descending aorta = in
renal vein = directly back to inferior vena cava = out
renal artery = between medulla –> interlobar artery –> arcuate artery (in arch between medulla and cortex, branches out perpendicular towards surface of kidney) –> interlobular artery –> afferent arteriole (blood supply to nephron)
venous = arterial system going backwards
what is a nephron
each kidney has ~ 1mil subunits called nephrons
what does nephron consist of
renal corpuscle = glomerulus (capillary loops), continuation of afferent arteriole and bowmans capsule
tubule
describe parts and structures of kidney - all
proximal tubule
loop of henle
distal convoluted tubule
collecting duct system
hollow tube surrounded by monolayer epithelial cells from here down
(cortex) efferent arteriole –> pct –> (medulla) descending thin limb of henles loop –> descending thick limb of henles loop –> ascending thin limb of henles loop –> ascending thick limb of henles loop –> (cortex) dct – cortical collecting down –> (medulla) medullary collecting duct –> medullary collecting ducts from other nephrons
describe renal corpuscle
entangled capillary loops around glomerulus surrounded by bowmans space
Bowman space = lined by monolayer epithelial cells
bownmans capsule = parietal layer not touching glomerulus, visceral layer = podocytes and middle = bowmans space
describe glomerulus
distal tubule = end of ascending limb of loop of henle
begining of macula densa
describe glomerular capillary wall
filtration barrier
foot processed interdigitate with other podocytes = v tightly surround capillary
describe glomerular capillary wall - filtration barrier
3 layers =
visceral glomerular epithelial cells - podocytes =
glomerular basement membrane
endothelial cells
things go through fenestration except cells and large proteins
connected by membrane = filtration slit
some size selection by foot processes = glomerular filtration
what is function of glomerulus
filters blood to make urine
describe vascular supply of nephron
peritubular capillaries provide blood to rest of system
blood composition becomes venous and then merges with vein
name and describe the 3 processes of urine formation
glomerular filtration
tubular secretion
tubular reabsorption
describe glomerular filtration
urine formation begins with filtration of plasma from glomerular capillaries into bowmans space
describe glomerular filtrate
fluid in bowmans space = cell free (no rbcs/wbcs) and except for proteins (albumins, iggs) contains all same substances and same concentrations as plasma
describe tubular secretion/reabsorption
as glomerular filtrate passes through tubules composition altered by movements of substances
what is difference between reabsorption and secretion
Reabsorption = filtered into bowmans space and get reabsorbed back to peritubular cap = tubules –> peritubular cap
secretion = from peritubular cap to tubular lumen = peritubular cap –> tubules
describe formation of urine
Movement of something from glomerulus to bowmans space then tubular secretion and reabsorption
describe how to find amount excreted
amount excreted = amount filtered + amount secreted - amount reabsorbed
differs from substance = amount and location
describe PAH excretion
para amino hippurate
bulk remains then all goes to urine
chemical
describe sodium and water excretion
lot reabsorbed but small amount excreted
99% kept
describe glucose excretion
body need all of it so takes everything back
if sick = like high blood sugar = not perfect and urine has glucose in it
describe rate of filtration, reabsorption or secretion
subject to physiological control
describe physiological control
when body content of substance goes above or below normal = homeostatic mechanisms can regulate substances bodily balance by changes these rates
what is juxtaglomerular apparatus
macula densa = tall columnar shaped cells
juxtagolmerular cells fill space and secrete renin
describe physiological control- ex
normal person drinks lots of water = reasborption of water decreased and excess water excreted in urine
drink a lot so pee alot
