The Urinary System: Renal Function Filtration, Reabsorption, Secretion, and Excretion

Which part of the nephron always has low permeability to water, regardless of hormone levels? Ascending loop of Henle Collecting duct Descending loop of Henle Proximal tubule

Ascending loop of Henle

Put the following in the appropriate sequence to indicate the pathway a substance must travel to be reabsorbed: (a) basolateral membrane of the tubular epithelial cells (b) peritubular space (c) luminal membrane of the tubular epithelial cell (d) capillary pore of the peritubular capillary

c, a, b, d

Factors that favor filtration at the glomerulus include __________.

capillary blood pressure and the concentration of proteins in Bowman's capsule

Filtrate becomes urine at the end of the __________.

collecting duct

Which of the following would not result in an increase in GFR? increased resistance in the afferent arteriole increased resistance in the efferent arteriole relaxation of mesangial cells increased glomerular pressure

increased resistance in the afferent arteriole

In a normal kidney in a healthy individual, glucose __________.

is freely filtered at the glomerulus

By the end of the proximal tubule, approximately 70% of the water and solutes have been reabsorbed. However, the fluid in the tubule is still iso-osmotic to plasma. This is because within the proximal tubule __________.

many solutes are actively transported, and water follows the solutes by passive diffusion

If clearance of a substance is greater than GFR, the substance is __________.

net secreted by the kidney

Tubular reabsorption __________.

permits reclamation of filtered items from the plasma, occurs in the loop of Henle, and is responsible for the movement of amino acids, CA2+, Cl- and water at the proximal convoluted tubule

The urine of an individual will contain glucose when __________.

plasma glucose concentration has reached renal threshold

The renal corpuscle is the site where __________.

plasma is filtered from the glomerulus into Bowman's capsule

The renal filtrate is formed in the kidney's outer shell, called the __________.

renal cortex

Secretion differs from filtration in that __________.

secretion is selective because it is carrier-mediated

Glucose reabsorption from the renal filtrate is due to __________.

sequential active transport and facilitated diffusion by the cells of the proximal tubule

In order to measure the clearance of a substance, one would need to know which of the following? the concentration of the substance in the plasma, the concentration of the substance in the urine, and the urine flow rate all answers are needed the glomerular filtration rate (GFR) the concentration of the substance in the urine the concentration of the substance in the plasma the urine flow rate

the concentration of the substance in the plasma, the concentration of the substance in the urine, and the urine flow rate

The nephron is the functional unit of the kidney because __________.

the nephron filters the plasma, reabsorbs critical molecules, and excretes the rest

The proximal and distal tubules differ in that __________.

the proximal tubule is "leakier" than the distal tubule, distal tubule cells possess a higher concentration of hormone receptors compared to proximal tubule cells, and proximal tubule cells have larger numbers of mitochondria

The proximal tubule is where_____________.

the reabsorption of the majority of ions, organic molecules, and vitamins takes place

Which is unlikely to be a consequence of kidney disease? Anemia Hyperglycemia Electrolyte imbalance Edema

Hyperglycemia

Urine is carried from the collecting duct to what structure next?

Renal pelvis

Which of the following substances is not secreted into the filtrate in the distal convoluted tubule? Protons Bicarbonate Water Potassium ions

Water

Para-aminohippuric acid (PAH) is used under clinical conditions to estimate and assess healthy kidney clearance function because __________. it is freely filtered at the glomerulus the remnants of PAH in renal capillaries are completely secreted it is not freely reabsorbed by any segment of the nephron all answers are correct PAH clearance rate equals the renal flow rate of the kidney

all answers are correct

Poisoning the Na-K-ATPase in the proximal tubule would likely __________.

decrease the amount of glucose reabsorption in this segment

In and around the urinary bladder, skeletal muscle can be found in the __________.

external urethral sphincter

In kidney renal tubules, all of the following substances normally are excreted into urine as it forms except __________. potassium ions glucose all answers are incorrect hydrogen ions

glucose

The ability of the nephron to filter substances based on size and charge is not due to the __________.

hydrostatic pressure