Ch. 18 HW Urinary System

Most solutes that are reabsorbed in the proximal convoluted tubule use which of the following pathways? transcellular paracellular

transcellular Yes, most substances are reabsorbed first through the luminal and then through the basolateral membranes of the proximal convoluted tubule.

Calculate the net filtration pressure if capillary hydrostatic pressure is 60 mm Hg, capillary osmotic pressure is 25 mm Hg, and capsular hydrostatic pressure is 10 mm Hg. 50 mm Hg 60 mm Hg 25 mm Hg 35 mm Hg

25 mm Hg Yes, 60 - (25 + 10) = 25 mm Hg. The two pressures that oppose filtration must be subtracted from the force favoring filtration.

The process of filtration involves movement of fluid and solutes from __________ to __________. afferent arteriole; glomerular capillaries glomerular capillaries; peritubular capillaries glomerular capillaries; Bowman's capsule peritubular capillaries; Bowman's capsule

glomerular capillaries; Bowman's capsule

Which of the following is NOT a secondary function of the kidneys? production of renin secretion of erythropoietin gluconeogenesis glycogenolysis

glycogenolysis

Each kidney contains over one million __________, the functional units of the kidney. renal corpuscles renal tubules nephrons peritubular capillaries

nephrons

Which of the following is the inner region of the kidney, which is darker with a striped appearance? renal pelvis cortex medulla nephrons

medulla

The process of eliminating urine from the body is called __________. reabsorption filtration micturition secretion

micturition

The active transport of which ion out of proximal convoluted tubule cells causes the reabsorption of both water and solutes? chloride sodium potassium

sodium Yes, the active transport of sodium out of the cell, across the basolateral membrane into the interstitium, provides the driving force for reabsorption of both water and solutes.

The decreased intracellular concentration of sodium in tubular cells during active transport is caused by which of the following mechanisms? passive sodium channels sodium-glucose cotransporter the sodium-potassium ATPase pump in the basolateral membrane the sodium-potassium ATPase pump in the luminal membrane

the sodium-potassium ATPase pump in the basolateral membrane Yes, this pump moves sodium out of the cell into the interstitium, thus decreasing intracellular sodium.

Of the 800 millimoles of glucose that is filtered by the kidneys each day, what percentage is reabsorbed? 100% 99.2% 99.4% 98.1%

100%

About __________ liters of fluid is filtered by the kidneys each day. 180 125 5 1.5

180

Why is inulin, an exogenous substance, useful in determining glomerular filtration rate (GFR)? Inulin's filtered load is greater than its excretion rate. Inulin is reabsorbed. Inulin is secreted from the peritubular fluid into the lumen of the renal tubule. Inulin is freely filtered and not reabsorbed or secreted.

Inulin is freely filtered and not reabsorbed or secreted.

Which of the following transporters in the luminal membrane results in secretion? potassium ion channel Na+-glucose cotransporter glucose carrier transporter Na+-H+ countertransport

Na+-H+ countertransport Yes, because this is a countertransporter, Na+ is transported into the cell and H+ is transported out of the cell into the lumen.

During reabsorption of water in the proximal convoluted tubule, what causes water to osmose from the lumen into the interstitial space? active transport of water a decrease in the osmolarity of the interstitium an increase in the osmolarity of the interstitium

an increase in the osmolarity of the interstitium Yes, the increase in osmolarity causes the water to move into the interstitium.

Which of the following substances is not normally found in filtrate? water and small solutes ions, such as sodium and potassium nitrogenous waste particles, such as urea blood cells and large particles

blood cells and large particles Yes, both blood cells and large particles, such as proteins, are not allowed to filter through a healthy glomerular membrane.

Which of the following conditions might lead to glucose levels exceeding the transport maximum in the proximal tubules? diabetes insipidus dehydration diabetes mellitus kidney stones

diabetes mellitus

What is the primary driving force (pressure) that produces glomerular filtration? gravity colloid osmotic pressure of blood hydrostatic pressure of blood (blood pressure)

hydrostatic pressure of blood (blood pressure) Yes, the hydrostatic pressure of blood forces fluid out of the glomerular capillaries.

Which of the following events does NOT take place during the process of micturition? increased parasympathetic activity decreased somatic neuron activity relaxation of the internal urethral sphincter increased sympathetic activity

increased sympathetic activity

If the osmotic pressure in the glomerular capillaries increased from 28 mm Hg to 35 mm Hg, would net filtration increase or decrease? net filtration would not be altered net filtration would decrease net filtration would increase

net filtration would decrease Yes, because osmotic pressure opposes filtration, increasing osmotic pressure would decrease net filtration.

What is the limiting factor for the reabsorption of most actively transported solutes in the proximal tubule? number of transport carriers in the luminal membrane number of transport carriers in the basolateral membrane number of sodium-potassium ATPase pumps in the basolateral membrane

number of transport carriers in the luminal membrane Yes, the number of carriers is the rate-limiting factor. For example, in Diabetes Mellitus, plasma glucose levels are very high, and the sodium-glucose transporter cannot transport (reabsorb) all the glucose passing through the proximal tubule. Glucose is therefore found in the urine.

Which substance would be found in higher concentration if the membrane were damaged? glucose chloride protein creatinine

protein Yes, large proteins are not normally filtered by a healthy glomerular membrane.

As the glomerular filtrate is formed, it flows from the Bowman's capsule into the __________. connecting tubule proximal convoluted tubule descending limb of the loop of Henle distal convoluted tubule

proximal convoluted tubule

The transport of solutes and fluid from the renal tubule into the peritubular capillaries is the process of __________. secretion filtration osmosis reabsorption

reabsorption

Which of the following is NOT a primary function of the urinary system? regulation of plasma osmolarity regulation of plasma ionic composition regulation of plasma volume regulation of insulin secretion

regulation of insulin secretion