Histology, embryology and biochem Flashcards
what are the 3 main functions of the kidneys and urinary tract
1) maintain water, electrolyte homeostasis, osmolarity and A-B balance 2) excrete toxic metabolic waste 3) endocrine gland
what are the 2 main metabolites excreted by the kidney
urea and creatinine
what are the 2 hormones the kidneys secrete
renin and erythropoietin
where are the kidneys located
upper retroperitoneal area
what covers the kidneys
thin, strong, collagen (fibrous) capsules
what is the hilum of the kidney
point of entry and exit for arteries, veins and ureters
what are the 2 main sections of the kidney
outer cortex and inner medulla
how many pyramids are their per kidney
8-18 - part of the medulla
what is in-between each pyramid
renal columns which are part of the cortex
what do pyramids drain into
renal papilla –> minor calyx –> major calico –> renal pelvis –> ureter
what is a nephron
basic functional unit of kidney
what are nephrons composed off
renal corpuscle and surrounded by renal tubules (blue)
what is the broad main function of the renal corpuscle
production and collection of glomerular filtrates
what is the broad main function of the proximal convoluted tubule
reabsorption of water, proteins, amino acids, carbs and glucose
what is the broad main function of the loop of Henle
creates hyper osmotic environment in medulla
what is the broad main function of the distal convoluted tubule
acid base and water balance - absorbs H2O Na and HCO3 - excretes K and H
what is the renal corpuscle made of
tuft of capillaries called the glomerulus and a cup of squamous cells enclosing to called bowman’s capsule
what blood supply do renal corpuscles have
afferent arteriole supplies and enters glomerular capillaries and efferent arteriole drains
what cells separate blood from the glomerular filtrate
capillary endothelium and podocytes
what connective tissue cells are present in renal corpuscles
mesangial cells that make connective core called mesangium
what are medullary rays
collecting duct, proximal and distal tubules all run perpendicular to the kidney surface
what effect does ADH have on the kidneys
increases permeability of collecting duct to water
what cells are found in the bladder
transitional epithelium / urothelium
what happens in metanophros of the kidney In embryology (3)
week 5 - becomes permanent - forms ureteric bud and metanephric blasteme
where do the kidneys originate form and when do they move to their final position
from pelvis -> L1 in weeks 6-9
where does the blood supply to the kidneys initially come from
common iliac arteries
what is a pelvic kidney
development abnormality where one kidney fails to ascend and is usually at the level of the common iliac
what is a horseshoe kidney
development abnormality where inferior poles of the kidney meet and fuse
what are 3 common bladder abnormalities
urachal fistula, urachal cyst, urachal sinus
what 4 criteria should be met to make an ideal marker for glomerular filtration rate (GFR)
appear at a constant rate / freely filtered by glomerulus / not be absorbed or secrete by tubules / not undergo extra renal elimination
what marker fits all of the GFR criteria but is not commonly used as impractical
inulin
what criteria does creatinine not meet as a GFR marker
constant rate - larger measures of creatinine when large reduction of GFR
what is clearance
volume of plasma cleared of a substance per minute
how would you measure clearance
([X]urine x urine volume) / ([X]blood x time)
what is clearance of creatine equal to
GFR
what 4 factors can affect levels of creatinine
age, sex, muscle mass, diet
what other methods can be used to measure GFR aside from creatine clearance
eGFR and Cr-EDTA
what defines proteinuria with glomerular damage
protein excretion >150 mg/ day = glomerular damage
what 4 broad causes can cause proteinuria
over flow / glomerular / tubular (not absorbed) / secreted
what is microalbuminuria
earliest sign of diabetic nephropathy - abnormal albumin excretion but undetectable by dipstick
what is the function of glomerular filtration
to selectively rid body waste and reabsorb important substances
