Organisms categorized as osmoconformers are most likely
1. found in fresh water lakes and streams
3. found in arid terrestrial environments
4. found in arid terrestrial environments with adequate moisture.
The advantage of excreting wastes as urea rather than as ammonia is that
1. urea can be exchanged for Na+.
2. urea is less toxic than ammonia.
3. urea requires more water for excretion than ammonia
4. urea does not affect the osmolar gradient.
What substance is secreted by the proximal-tubule cells and prevents the pH of urine from becoming too acidic?
If these active transport mechanisms for sodium ions in the human kidney were to stop completely, how would urine production be affected?
1. A less-than-normal volume of hypoosmotic urine would be produced.
2. A greater-than-normal volume of isoosmotic urine would be produced.
3. A greater-than-normal volume of hyperosmotic urine would be produced.
4. A less-than-normal volume of isoosmotic urine would be produced.
Processing of filtrate in the proximal and distal tubules accomplishes what important function?
1. sorting plasma proteins according to size
2. converting toxic ammonia to less toxic urea
3. maintaining a constant pH in body fluids
4. reabsorbing urea to maintain osmotic balance
What is unique about transport epithelial cells in the ascending loop of Henle in humans?
1. Their membranes are impermeable to water.
2. They are not in contact with interstitial fluid.
3. 50% of their cell mass is comprised of the smooth endoplasmic reticulum.
4. They are not affected by high levels of nitrogenous wastes.
Which one of the following, if present in a urine sample, would likely be caused by trauma?
1. amino acids
In a laboratory experiment with three groups, one group of people drinks pure water, a second group drinks an equal amount of beer, and a third group drinks an equal amount of concentrated salt solution all during the same time period. Their urine production is monitored for several hours. At the end of the measurement period, which group will have produced the greatest volume of urine, and which group the least?
1. beer the most, salt solution the least
2. salt solution the most, water the least
3. water the most, beer the least
4. beer the most, water the least
What will happen to glomerular filtration rate (GFR) if efferent arteriole smooth muscle is contracted?
1. GFR will increase
2. GFR will decrease
3. GFR will remain constant
4. GFR can either increase or decrease
Carbonic anhydrase inhibitors act primarily on the
1. collecting duct
2. distal convoluted tubule
3. loop of Henle
4. proximal convoluted tubule
Glomerular filtration rate can be determined by calculating renal clearance of
3. para-amino hippuric acid.
During the processing of the glomerular ultrafiltrate
1. compounds present in excess of the transport maximum for the transport protein will appear in the urine.
2. the majority of glucose is reabsorbed by the distal convoluted tubule.
3. ADH alters the permeability of all portions of the tubule to water.
4. the fluid volume is reduced to 1/2 of its original volume by the proximal convoluted tubule.
The mucosa of the bladder is comprised of:
1. smooth muscle
2. squamous epithelium
3. transitional epithelium
4. simple columnar epithelium
What causes urine to flow from the kidneys to the bladder?
2. hydrostatic pressure
4. osmotic pressure
Which of the following statements about the urinary system is INCORRECT?
1. It produces renin, which helps regulate blood pressure.
2. It metabolizes vitamin D to its active form.
3. It carries out the majority of gluconeogenesis in the body.
4. It produces erythropoietin, which stimulates red blood cell formation.
Peristaltic muscular contractions are important for conveying urine through the excretory system, much like peristalsis in the digestive tract. Peristalsis of the detrusor muscle of the urinary bladder is controlled by:
1. conscious control of the skeletal muscle
2. sympathetic nervous impulses
3. parasympathetic nervous impulses
4. impulses from the cerebral cortex
1. is the major mineralocorticoid hormone secreted by the kidney
2. promotes the secretion of Na+ in the late distal convoluted tubule and the cortical region of the collecting duct
3. stimulates the secretion of K+ from the peritubular blood into the distal convoluted tubule
4. is a protein hormone secreted by the adrenal cortex
Which of the following statements regarding renal handling of water by the kidneys is correct?
1, In the absence of vasopressin, urine is isoosmotic with plasma.
2. In the absence of vasopressin, water cannot be reabsorbed in the proximal tubules.
3. In the absence of vasopressin, the cortical collecting ducts have very low permeability to water.
4. In the absence of vasopressin, the distal tubules secrete water.
If the pH of the blood decreases, the pH of the urine will
3. be unaffected.
4. first increase then decrease
A blockage in a glomerulus would directly obstruct blood flow into which vessel?
1. afferent arteriole
2. efferent arteriole
3. interlobular artery
4. interlobar artery