Glomerular Filtration rate Flashcards
Glomerular Filtration Rate
the amount of filtrate formed in all renal corpuscles of both kidneys per minute.
GFR is directly related to
NFP
Two ways GFR is regulated
adjusting the blood flow in and out of glomerulus
altering surface area of the glomerulus capillaries
when does GFR increase
when blood flow in capillaries increase
Regulates Glomerulus blood flow
Control of the diameters of Afferent and Efferent arterioles
Decreases blood flow into glomerulus
Constriction of Afferent arteriole
Increases blood flow into glomerulus
Dilation of Afferent arteriole
3 mechanisms that control GFR
Renal Autoregulation, Neural Regulation and Hormonal regulation
Two components of renal autoregulation
Myogenic Mechanism
Tubuloglomerular feedback
Myogenic Mechanism
High BP causes arterioles to stretch
High BP causes High GFR
When arterioles stretch, they contract
Contraction slows down blood flow, decreases GFR
Tubuloglomerular feedback utilizes what cells to have negative feedback regulation
Macula Densa
Tubuloglomerular feedback
Increase GFR causes increase filtration fluid of renal tubule
the increased fluid doesn’t allow for much reabsorption of water, sodium and chloride ions.
Macula densa senses increase delivery of ions and inhibit NO, a vasodilator.
Afferent arterioles constrict allowing for flow to decrease, decreasing GFR.
Neural Regulation of GFR
NE is released which causes vasoconstriction
two consequences of the lowering of renal blood flow
reduces urine output
permits greater blood flow to other body tissues
two hormones that contribute towards regulation of GFR
Angiotensin II and ANP
