Renal System SEM2 Flashcards
What is the main function of the kidneys
Where filtrate is processed; either reclaimed or excreted as urine
What is the role of the renal cortex
Filtration and bulk processing
What is the role of the renal medulla
Fine tuning for body homeostasis
What is the papilla of the kidney
Where urine is collected
What does the cortex of the kidney consist of
-all glomeruli
-convoluted tubules
-cortical collecting ducts
What does the medulla of the kidney consist of
-loops of Henle
-medulla collecting ducts
What do the renal lobes consist of
-cortex and medulla
-urine drains into cavity (calyx)
What is the role of the calyx
Collects urine - peristalsis to bladder
What are the two nephron groups in the kidney and their starting position
Short-looped nephron and long-looped nephron - start in cortex
Characteristics of short looped nephrons
-thick limb of henle
-in cortex/outer medulla
Characteristics of long-looped nephrons
-thick limb is deep
-helps to concentrate urine
What is the meaning of autoregulatory in regards to kidneys
Stability of perfusion and of GFR over physiological blood pressure
How is circulation in the kidneys protected
By autoregulation of renal blood flow
What is the first capillary bed in the blood circulation of kidneys
1st capillary bed = glomerulus = filtration
What is the second capillary bed in the blood circulation of the kidneys
2nd capillary bed = peritubular = reabsorption and secretion
What does high blood flow support
High glomerular filtration rate
What are starling forces
Movement of fluids out and back into capillaries
What does P mean in the darling force equation
P = hydrostatic pressure (pushing pressure)
What does pi mean in the darling force equation
Pi = colloid oncotic pressure
(Pulling pressure)
Is net push or net pull greater in the glomerular capillary
The net push is greater than the net pull
What does PGC indicate
Pushing pressure progressively falls
What does piGC indicate
Pulling pressure progressively rises
How is GFR decreased
By ANGII(2); noradrenalin, ET-1
How is GFR increased
By nitric oxide;prostaglandins
What is the balance of afferent and efferent constriction measured by
Change in PGC
What does increased afferent result in
-reduced blood flow into capillary
-reduced hydrostatic pressure in capillary
What does increased efferent result in
-reduced flow out of capillary
-sustains hydrostatic pressure in capillary
What are the 3 layers of the filtration barrier
1)capillary endothelium (-ive charge)
2)basement membrane (-ive charge)
3)podocytes (epithelium) slit diaphragm
what does the brush border result in
high surface area for transport
what are characteristics of the proximal tube
-high capacity
-geared for bulk transport
-lots of mito (oxidative phosphorylation)
-leaky epithelial (permeable tight junctions)
is water reabsorption present in the thick ascending limb (TAL) in the loop of henle
no water reabsorption - TAL sometimes called diluting segment
is water reabsorption present in the distal convoluted tubule
limited water reabsorption- no AQP2
what occurs at the collecting ducts
final chance to process urine - another nephron joins and drains to calyx
what transcriptional factor activates the mineralocorticoid receptor in the principal cell of the collecting ducts
aldosterone
what does the hypertonic medulla create the potential to excrete
-dilute urine (100mOsm)
-concentrated urine (1200 mOsm)
