M1U2: RENAL PHYSIOLOGY Flashcards
how can the concept of ADH control be summarized ?
^body hydration vADH ^urine volume
vbody hydration ^ADH vurine volume
How is aldosterone correlated to the body’s sodium concentration ?
production of aldosterone is controlled by the body’s sodium concentration
what is the production of ADH deteremined by ?
by the state of body hydration
what makes the osmotic gradient of the renal medulla unique ?
only tissue in the human body that is hypertonic with respect to normal plasma
this mechanism actively happens in the loops of henle
countercurrent multiplier mechanism
this mechanism passively happens and involves the vasa recta
countercurrent exchange mechanism
what is the main purpose of the countercurret multiplier mechanism ?
maintain the gradient hypertonicity of the medullary interstitium
what is the main purpose of the countercurrent exchange mechanism ?
providing nutrients to the medulla and remove water from the interstitium and distribute it to the rest of the body
consequently maintains tonicity of medullary interstitium
what are the three mechanisms by which the tubules participate in maintaining blood pH within the normal range ?
Bicarbonate Recovery
Excretion via Titrable Acids
Excretion via Ammoniuim Salt Formation
which mechanism used to maintain blood pH within normal range involves the secretion of H+ ions in the proximal tubular lumen ?
bicrbonate recovery
which mechanism used to maintain blood pH within normal range involves neutral phosphate salts present in the tubular lumen ?
Excretion via Titrable Acids
which mechanism used to maintain blood pH within normal range depends on ammonia secretion and subsequent exchange of sodium for ammonium ions ?
Excretion via Ammonium Salt Formation
which mechanism used to maintain blood pH within normal range directly removes acids from the body while reabsorbing sodium and bicarbonate ions via peritubular capillaries ?
Excretion via Titrable Acids
What is the difference between the ionized and non ionized form of ammonia in the extraction via ammonium salt formation mechanism ?
not ionized ammonia: lipid soluble, can readily diffuse through the cell membrane of tubular cells to the tubular lumen
ionized ammonia: cannot diffuse to the tubular cells, is excreted
Any deviation from __ pH-__ pH is considered pathologic
7.35 - 7.45
What happens to hydrogen ions in cases of alkalosis and acidosis ?
alkalosis: retained
acidosis: secreted
How is plasma sodium related with blood pressure ?
↓ plasma Na => ↓ retention of water in circulation => ↓ overall blood volume => ↓ blood pressure
what part of the juxtaglomerular apparatus detects a decrease in blood pressure ?
macula densa
what does aldosterone stimulate in the RAAS ?
sodium reabsorption in the DCT and collecting ducts
what does ADH stimulate in the RAAS ?
reabsorption of water in the DCT and collecting ducts
what is the specific gravity of plasma ultrafiltrate and why ?
1.010, due to the lack of protein
what makes plasma ultrafiltrate different from regular blood plasma ?
plasma ultrafiltrate is normally free of blood cells and protein
What is the normal glomerular filtration rate ?
90 - 120 mL/minute
how much ml of filtered plasma do the kidneys approximately process each day ? and the final urine volume ?
180,000 ml
600 - 1,800 mL
