Urine Formation by the Kidneys: II. Tubular Reabsorption and Secretion

What is the fundamental equation that describes the sum of the three basic renal processes leading to the final composition of urine?

If the plasma glucose concentration is 1 gram per liter and the glomerular filtration rate is 180 liters per day, what is the total amount of glucose filtered by the kidneys each day?

What is the average transport maximum for glucose in an adult human?

At what approximate plasma glucose concentration does glucose first begin to appear in the urine, a point known as the threshold?

What percentage of the filtered load of sodium and water is normally reabsorbed by the proximal tubule?

What is the primary mechanism for the reabsorption of glucose by the renal tubule?

Which sodium-glucose co-transporter is responsible for reabsorbing approximately 90 percent of the filtered glucose in the early part of the proximal tubule?

What is the primary function of pinocytosis in the proximal tubule?

What is the approximate normal net reabsorptive force that moves fluid and solutes from the renal interstitium into the peritubular capillaries?

What is the term for the intrinsic ability of the renal tubules to increase their reabsorption rate in response to an increased tubular load?

Which hormone is described as perhaps the body’s most powerful sodium-retaining hormone?

What is the most important renal action of antidiuretic hormone (ADH)?

Loop diuretics such as furosemide, ethacrynic acid, and bumetanide exert their powerful diuretic effect by inhibiting which transporter?

Thiazide diuretics, widely used to treat hypertension, primarily inhibit which transport mechanism in the early distal tubule?

What is the primary function of Type A intercalated cells in the late distal tubules and collecting tubules?

What is the primary function of the principal cells located in the late distal tubules and cortical collecting tubules?

Potassium-sparing diuretics like spironolactone and eplerenone exert their effect by which mechanism?

Approximately what percentage of the filtered loads of sodium, chloride, and potassium are reabsorbed in the loop of Henle, mostly in the thick ascending limb?

Which polysaccharide, not produced in the body, is used to measure the GFR because it is freely filtered but not reabsorbed or secreted by the renal tubules?

Why does creatinine clearance provide a reasonable, though not perfect, estimate of GFR in clinical settings?

How is the filtration fraction calculated?

If the clearance rate of a substance is found to be greater than the clearance of inulin, what does this indicate about the renal handling of that substance?

What is the approximate average extraction ratio for para-aminohippuric acid (PAH) in normal kidneys?

By what process is water always reabsorbed passively across the tubular epithelial membrane?

Which part of the loop of Henle is described as being virtually impermeable to water, a characteristic important for concentrating the urine?

What is the approximate transport maximum for actively secreted para-aminohippuric acid (PAH)?

According to the table of transport maximums for actively secreted substances, what is the value for creatinine?

What percentage of the urea filtered by the glomerular capillaries is typically reabsorbed from the tubules?

What happens to the concentration of creatinine in the tubular fluid relative to its concentration in the plasma as it moves along the proximal tubule?

What is the major renal tubular site of action for the hormone aldosterone?

Which water channel protein is responsible for the high water permeability of the proximal tubule?

In the first half of the proximal tubule, sodium is primarily reabsorbed by which mechanism?

How does the concentration of sodium in the tubular fluid change as the fluid passes along the proximal tubule?

What is the function of the sodium-hydrogen exchanger in the luminal membrane of the proximal tubule?

What is the approximate transport maximum for lactate reabsorption?

In the basic mechanism for active sodium transport, which pump on the basolateral membrane is responsible for creating a low intracellular sodium concentration?

What is the term for transport that is coupled indirectly to an energy source, such as being driven by an ion gradient?

What approximate percentage of the filtered glucose is reabsorbed by the SGLT1 transporter in the latter segments of the proximal tubule?

What is the approximate transport maximum for urate reabsorption by the tubules?

The transport maximum for amino acids that are actively reabsorbed by the tubules is approximately what value?

The transport of some substances, like sodium in the proximal tubule, depends on the electrochemical gradient and the time the substance remains in the tubule. What is this type of transport referred to as?

In the more distal parts of the nephron where sodium reabsorption exhibits a transport maximum, which hormone can increase this transport maximum?

How does activation of the sympathetic nervous system affect sodium reabsorption?

What is the primary effect of Atrial Natriuretic Peptide (ANP) on renal tubular reabsorption?

What are the primary effects of Parathyroid Hormone (PTH) on the renal tubules?

What is the approximate normal colloid osmotic pressure of the peritubular capillary plasma (πc)?

What is the approximate normal hydrostatic pressure inside the peritubular capillaries (Pc), which opposes reabsorption?

According to Table 27-5, which summarizes conditions influencing renal function, what is the early effect of a high dietary protein intake on Renal Blood Flow (RBF) and Glomerular Filtration Rate (GFR)?

The late distal tubule and subsequent cortical collecting tubule are composed of which two distinct cell types?

What is the approximate clearance rate for glucose in a healthy individual under normal conditions?