Urine Formation Flashcards
three main processes of urine formation
glomerular filtration
reabsorption
secretion
average amount of blood filtered by kidneys per minute
how much is it compared to blood pumped by each ventricle per minute
1100-1200 ml
1/5th
which three layers does this filtration take place
endothelium of glomerular blood vessels
basement membrane
epithelium of bowman’s capsule
epithelial cells of bowman’s capsule are called
podocytes
how are the podocytes arranged
with minute spaces in between called filtration slits or slit pores
blood is filtered so finely through the membranes that almost all constituents of plasma except __________ pass onto the lumen of bowman’s capsule
proteins
glomerular filtration is also known as
ultra filtration
amount of filtrate formed by kidneys per minute is called
glomerular filtration rate
GFR in a healthy individual
125 ml/minute
180 litres/day
regulation of glomerular filtration rate is carried out by
juxta glomerular apparatus
JGA is a special sensitive region formed by cellular modifications in the __________________________ and the _________________________ at the location of their contac
distal convulated tubule
afferent arteriole
a fall in GFR can activate the JGA to do what?
release renin which stimulates the glomerular blood flow which brings GFR back to normal
amount of urine released per day
1.5 litres
how much percent of filtrate is reabsorbed
99
reabsorption of glucose, amino acids, Na+, etc takes place by which type of transport
active
nitrogenous wastes are reabsorbed by which type of transport
passive
water is reabsorbed by which type of transport and in which segments of the nephron
passive
initial segments of nephron
during urine formation, which substances are secreted by tubular cells and for what?
H+, K+, NH4+
maintenance of ionic and acid-base balance of body fluids
