Ch 25 HW

Focus your attention on the "key players" outlined in the first part of Focus Figure 25.1. Drag and drop the terms to the appropriate blanks in the sentences. Terms may be used once, more than once, or not at all.

1. The long nephron loops of the juxtamedullary nephrons are located in the renal medulla. 2. The long nephron loops create the medullary osmotic gradient and act as countercurrent multipliers. 3. The vasa recta preserve the medullary osmotic gradient and act as countercurrent exchangers. 4. The collecting ducts use the medullary osmotic gradient to concentrate urine.

Through the tubuloglomerular feedback mechanism, how would an increase in filtrate NaCl concentration affect afferent arteriole diameter?

Afferent arteriole diameter would decrease.

Which of the following processes would be considered as a secretory rather than an excretory activity?

Aldosterone release by the adrenal glands

Match these vocabulary terms to their meanings.

An elevated level of urea in the blood is uremia. Renin is released by cells of the juxtaglomerular apparatus in response to afferent arteriole pressure and the degree of stretch of the arteriole wall. The structural and functional unit of the kidney is a nephron. The specialized capillary bed responsible for the pressure that drives filtration is the glomerulus.

Why do you have to carefully monitor certain patients who are on "loop diuretics" to lower their blood pressure?

Certain diuretics are not specific and in addition to getting rid of excess water, additional ions like potassium will be secreted. Submit

The lab results of a newly admitted patient indicate renal impairment. How might this affect the dosing regimen of drugs that are excreted by the kidney?

The dosage or the dosage interval may need to be reduced.

Match these prefixes to their meanings.

The prefix ur- means urine, urinary tract, or urea. The prefix nephr- means kidney. The prefix juxta- means situated near. The prefix glomerul(o)- means glomerulus of the kidney.

The myogenic mechanism of renal autoregulation primarily involves smooth muscle in which blood vessels?

afferent arterioles

Upon reaching what point in the nephron is reabsorption (1) dependent upon the body's needs at the time and (2) regulated by hormones?

distal convoluted tubule

In what part of the renal tubule does parathyroid hormone (PTH) promote the reabsorption of calcium ions?

distal convoluted tubule (DCT)

GFR regulation mechanisms primarily affect which of the following?

glomerular hydrostatic pressure (HPg)

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

glomerulus

What does a high concentration of NaCl in the renal tubule at the juxtaglomerular apparatus (JGA) most likely indicate?

insufficient NaCl reabsorption due to high GFR

Which of the following are mechanisms of intrinsic control of glomerular filtration (renal autoregulation)?

myogenic mechanism and tubuloglomerular feedback

What area of the nephron is responsible for the reabsorption of most of the water from the filtrate as well as most nutrients?

proximal convoluted tubule

Granular cells of the juxtaglomerular apparatus (JGA) regulate GFR indirectly through which mechanism?

renin-angiotensin mechanism

Approximately 80% of the energy used for active transport is devoted to the reabsorption of __________.

sodium

Focus your attention on Focus Figure 25.1. Which of the following is NOT a property used to establish the medullary osmotic gradient?

the blood flow through the ascending and descending portions of the vasa recta Submit

Which of the following best describes glomerular filtration rate (GFR)?

the volume of filtrate created by the kidneys per minute

Macula densa cells of the juxtaglomerular apparatus (JGA) regulate GFR through which intrinsic mechanism?

tubuloglomerular feedback