Urinary Homework

You've counseled Mr. Boulard about how to prevent recurrence of his hypokalemia. Which of the statements he makes indicates a need for further instruction?

"There's lots of potassium in regular table salt, so I'll just use more."

Match the following terms to their definitions. Drag the appropriate labels to their respective targets. 1 Site of filtrate formation. 2 Site that drains the distal convoluted tubule. 3 Blood supply that directly receives substances from the tubular cells. 4 Site at which most of the tubular reabsorption occurs

1 Glomerulus 2 Collecting duct 3 Peritubular capillaries 4 Proximal convoluted tubule

1. Low pressure, porous vessels that reabsorb solutes and water from the tubule cells 2. High pressure vessel that forces fluid and solutes into the glomerular capsule. 3. May form meandering vessels or bundles of long straight vessels. 4. Play a role in urine concentration. 5. Fenestrated vessels that allow passage of all plasma elements but not blood cells.

1. Peritubular capillaries 2. Afferent arterioles 3. Efferent arterioles 4. Vasa recta 5. Glomerular capillaries

Secondary active transport of solutes requires the presence of all of the following except __________.

ATP *NEEDS* transcellular movement concentration gradients membrane transport proteins

Explain how an angiotensin converting enzyme inhibitor (ACE inhibitor) such as captopril would be effective as an antihypertensive.

Ace inhibitors interrupt the production of angiotensin II (which normally constrict the blood vessels) allowing your blood vessels to relax and lower blood pressure

Cortical nephrons are responsible for producing concentrated urine. T/F

False

High blood pressure triggers granular cells of the juxtaglomerular complex to release renin T/F

False

The myogenic mechanism reflects the tendency of vascular smooth muscle to stretch. T/F

False

Suppose that a patient has a failing liver and is unable to make normal levels of albumin for the blood plasma. If all other factors remain the same, what would be the effect on the amount of filtrate produced?

Filtrate production would increase. (the blood's osmotic pressure would drop, leading to a rise in filtrate production.)

If blood pressure drops very low (MAP is below 80mmHg) renin enzyme will be secreted by granular cells. Which of the following is NOT likely to occur?

Kidney perfusion will increase.

What would happen if the capsular hydrostatic pressure were increased above normal?

Net filtration would decrease.

The relatively long half-life of lipid-soluble hormones (steroid hormones) compared to water-soluble hormones is due in part to the way that these hormones are passed into the filtrate from the glomerular capillaries. From the list below select the best explanation for why lipid-soluble (steroid) hormones have a relatively long half-life.

Steroid hormones travel in the plasma on large transport proteins that cannot pass through the filtration membrane.

If the diameter of the afferent arterioles leading to the glomerulus decreases (vasoconstriction), which of the following is NOT likely to occur?

Systemic blood pressure will decrease. *Will occur* Glomerular filtration rate will decrease. Net filtration pressure will decrease. Urine output will decrease.

If the diameter of the efferent arterioles leading away from the glomerulus increases (vasodilation), which of the following is NOT likely to occur?

Systemic blood pressure will decrease. *Will occur:* Net filtration pressure will decrease. Glomerular filtration rate will decrease. Urine output will decrease.

If the diameter of the afferent arterioles leading to the glomerulus increases (vasodilation), which of the following is NOT likely to occur?

Systemic blood pressure will go up.

If the diameter of the efferent arterioles leading away from the glomerulus decreases (vasoconstriction), which of the following is NOT likely to occur?

Systemic blood pressure will go up. *Will occur* Glomerular filtration rate will increase. Net filtration pressure will increase. Urine output will increase.

Which of the following is incorrect?

The concentration of urine is lower when urine volume is reduced. *TRUE* Urine concentration and volume are determined by countercurrent mechanisms The kidneys produce a large volume of dilute urine when overhydrated. The kidneys produce a small volume of concentrated urine when dehydrated.

Mr. Boulard's blood pressure is quite high. How would this affect his nephron function? Choose the statement below that is most accurate.

The heart releases atrial natriuretic peptide that reduces sodium reabsorption at the kidney when blood pressure increases.

Select the correct statement about the nephrons.

The parietal layer of the glomerular capsule is simple squamous epithelium. *False* Podocytes are the branching epithelial cells that line the tubules of the nephron. The glomerulus is correctly described as the proximal end of the proximal convoluted tubule. Filtration slits are the pores that give fenestrated capillaries their name.

Which of the following is NOT one of the things that must happen for micturition to occur?

The pontine storage center must be activated.

Select the correct statement about the ureters.

The ureters are capable of peristalsis like that of the gastrointestinal tract. *false* The ureter is innervated by parasympathetic nerve endings only. Ureters contain sphincters at the entrance to the bladder to prevent the backflow of urine. The epithelium is stratified squamous like the skin, which allows a great deal of stretch.

Hydrostatic pressure is the primary driving force of plasma through the filtration membrane into the capsular space. All but one of the following statements reflects why hydrostatic pressure is so high in the glomerular capillaries. Select the one statement that does NOT explain the high pressure within the glomerular capillaries.

The volume of plasma in the efferent arteriole is higher when compared to the afferent arteriole.

In the kidneys, the countercurrent mechanism involves the interaction between the flow of filtrate through the nephron loop of the juxtamedullary nephrons (the countercurrent multiplier) and the flow of blood through the limbs of adjacent blood vessels (the countercurrent exchanger). This relationship establishes and maintains an osmotic gradient extending from the cortex through the depths of the medulla that allows the kidneys to vary urine concentration dramatically. T/F

True

Salt is actively transported out of the filtrate in the nephron loop. T/F

True

Which of the following hormones acting on the collecting duct is most responsible for retaining sodium ions in the blood?

aldosterone

Urinary incontinence may occur if a person has ______.

an overactive detrusor muscle

Reabsorption of sodium in the medulla by active transport is undertaken by cells that compose which of the following?

ascending nephron loop

Which of the choices below is NOT a method by which the cells of the renal tubules can raise blood pH?

by secreting sodium ions

What is the effect of antidiuretic hormone on the cells of the collecting duct?

causes aquaporins to be inserted into the apical membranes

The presence of protein in the urine indicates which of the following?

damage to the filtration membrane

Which of the following would NOT inhibit micturition?

detrusor contraction *would* increase in sympathetic activity decrease in parasympathetic activity increase in somatic muscle activity

Which of the choices below is NOT a function of the urinary system?

eliminates solid, undigested wastes and excretes carbon dioxide, water, salts, and heat *DO:* helps maintain homeostasis by controlling the composition, volume, and pressure of blood maintains blood osmolarity regulates blood glucose levels and produces hormones

The glomerular capsular space contains ________.

filtrate

Which of the choices below is a function of the nephron loop?

form a large volume of very dilute urine or a small volume of very concentrated urine

Glomerular filtration rate can be controlled by manipulating one major variable, which is ________.

glomerular hydrostatic pressure

Your patient's urinalysis shows a large amount of protein in the urine. This suggests a problem in the ____________

glomerulus

Which cells of the juxtaglomerular apparatus secrete renin?

granular cells

Excretion of dilute urine requires ________.

impermeability of the collecting tubule to water

Cells and transport proteins are physically prevented from passing through the filtration membrane. This has the following effect on filtration.

increasing osmotic pressure in the glomerular capillaries that reduces the amount of filtration

Which of the choices below is the salt level-monitoring part of the nephron?

macula densa

The mechanism that establishes the medullary osmotic gradient depends most on the permeability properties of the ________.

nephron loop

Which of the following is NOT a part of the juxtaglomerular complex?

podocyte cells

Which of the following is NOT a function of the kidneys?

regulate body fluid by controlling excretion from sweat glands

What structure receives blood from the efferent arteriole of a juxtamedullary nephron?

vasa recta