Renal (10-11) Flashcards
How does the GFR change with age?
Decreases -partly due to reduction in number of nephrons
How does GFR in fetal life compare to that of the adult?
Low- homeostatic functions performed by the placenta
What are the two types of nephrons in birds?
Reptilian -type nephron ( no loop of Henule)
Mammalian-type nephrons (with loops of Henle)
How can birds regulate osmolaity after the kidney?
Altered in the cloaca
Antiperistaltic contractions move cloaca content to intestine
What additional way can birds regulate salt balance
Salt glands
Birds that drink sea water
In what form is nitrogen excreted in birds?
Uric acid
Under normal conditions our kidneys produce (hypotonic /hypertonic) urine
Hypertonic
Produce concentrated urine
If there is a high water load in the body, will the kidney produce hyper or hypotonic urine?
Hypotonic
Where does water reabsorption NOT occur in the nephron?
Ascending limb
What is the pressure in the peritubular capillaries compared to the glomerular capillaries?
More oncotic pressure
Pull water in from the interstitial fluid that is reabsorbed in the PT
Very low hydrostatic pressure in peritubular capillaries
The medullary intersitium is hyper-/iso-/hypo-tonic to the tubule lumen??
Hypertonic
The high concentration of the interstitium draws water out of the nephron lumen
What is required form formation of concentrated urine?
Hypertonic medullary interstitium
High water permeability in thin descending limb and collecting ducts
Reabsorption of water by vasa recta
What are the three main solutes responsible for the hypertonicity of the medulla?
Na+, Cl-, and urea
In the descending thin limb ______ is reabsorbed, which (increase/decrease) the osmolaity of the tubular fluid
Water
Increases
In the thin ascending limb, ______ is reabsorbed
NaCl
