1) The mechanism that establishes the medullary osmotic gradient depends most on the permeability properties of the ________.
A) loop of Henle
An increase in the permeability of the cells of the collecting tubule to water is due to ________.
an increase in the production of ADH
The glomerulus differs from other capillaries in the body in that it ________.
C) is drained by an efferent arteriole
The descending limb of the loop of Henle ________.
D) contains fluid that becomes more concentrated as it moves down into the medulla
Select the correct statement about the ureters.
C) The ureters are capable of peristalsis like that of the gastrointestinal tract.
The fatty tissue surrounding the kidneys is important because ________.
B) it stabilizes the position of the kidneys by holding them in their normal position
The juxtaglomerular apparatus is responsible for ________.
D) regulating the rate of filtrate formation and controlling systemic blood pressure
The chief force pushing water and solutes out of the blood across the filtration membrane is ________.
C) glomerular hydrostatic pressure (glomerular blood pressure)
Which of the following statements describes the histology of the ureters?
A) They are trilayered
(mucosa, muscularis, and adventitia).
Which of the following acts as the trigger for the initiation of micturition (voiding)?
A) The stretching of the bladder wall serves as the trigger.
Most electrolyte reabsorption by the renal tubules ________.
C) is hormonally controlled in distal tubule segments
The fluid in the glomerular (Bowmanʹs) capsule is similar to plasma except that it does not contain a significant amount of ________.
D) plasma protein
A disease caused by inadequate secretion of antidiuretic hormone (ADH) by the pituitary gland with symptoms of polyuria is ________.
B) diabetes insipidus
An important characteristic of urine is its specific gravity or density, which is ________.
Place the following in correct sequence from the formation of a drop of urine to its elimination from the body.
1. major calyx
2. minor calyx
6. collecting duct
Select the correct statement about the nephrons.
A) The parietal layer of the glomerular capsule is simple squamous epithelium.
What would happen if the capsular hydrostatic pressure were increased above normal?
B) Net filtration would decrease.
Tubular reabsorption ________.
B) by active mechanisms usually involves movement against an electrical and/or chemical gradient
Reabsorption of high levels of glucose and amino acids in the filtrate is accomplished by ________.
D) secondary active transport
While the kidneys process about 180 L of blood-derived fluids daily, the amount that actually leaves the body is ________.
C) 1%, or 1.8 L
Fetal kidneys do not have to work very hard because ________.
C) the placenta allows the motherʹs urinary system to clear the waste from fetal blood
Which of the following best describes kidney function in older adults (70 years or older)?
D) Kidney function decreases due to kidney atrophy.
The factor favoring filtrate formation at the glomerulus is ________.
B) the glomerular hydrostatic pressure
If the Tm for a particular amino acid is 120 mg/100 ml and the concentration of that amino acid in the blood is 230 mg/100 ml, the amino acid ________.
C) will appear in the urine
If one says that the clearance value of glucose is zero, what does this mean?
C) Normally all the glucose is reabsorbed.
As the renal artery approaches the kidney, it branches to supply the renal tissue. Place the following in correct sequence starting from the renal artery.
2. cortical radiate
In the ascending limb of the loop of Henle ________.
D) the thick segment moves ions out into interstitial spaces for reabsorption
Select the correct statement about urinary system development.
A) Kidneys develop from urogenital ridges.
The disruption in homeostasis known as pyelitis is ________.
C) an infection of the renal pelvis and calyces
The capillary bed that surrounds the descending and ascending loop of Henle is called the ________.
Answer: vasa recta
The ________ mechanism is the general tendency of vascular smooth muscle to contract when stretched.
Sodium-linked water flow across a membrane is called ________ water reabsorption.
Explain the path of the blood vessels in the kidney.
The renal artery divides into smaller
segmental arteries, which in turn branch into lobar arteries.
Lobararteries branch and enter the columns as interlobar, then turn and follow the
cortex-medulla boundary as arcuate arteries. Cortical radiate arteries travel up into the cortex and branch into afferent arterioles, which enter the Bowmanʹs capsule as glomerular capillaries and exit as efferent arterioles branching further into peritubular capillaries and the vasa recta. These capillaries return via the
cortical radiate, arcuate, interlobar, lobar, segmental, and renal veins.
Explain how filtration works in the glomerular capillaries.
The glomerular capillaries are fenestrated, allowing fairly large molecules to pass through. The substances must pass through the basement membrane, where they are further selected for size by the
filtration slits of the podocytes.
List 3 substances that are abnormal urinary constituents and provide the proper clinical term for such abnormalities.
Abnormal urinary constituents include the following (the clinical term for each is listed in parentheses):
proteins (proteinuria or albuminuria),
ketone bodies (ketonuria),
bile pigments (bilirubinuria),
and leukocytes (pyuria).
Explain the role of aldosterone in sodium and water balance.
Aldosterone targets the distal tubule and collecting duct and enhances sodium-ion reabsorption so that very little leaves the body in urine.
Aldosterone also causes increased water reabsorption because, as sodium is reabsorbed, water follows it back into the blood.
List and describe 3 pressures operating at the filtration membrane, and explain how each influences net filtration pressure.
Glomerular hydrostatic pressure is the chief force pushing water and solutes across the filtration membrane.
The higher the glomerular hydrostatic pressure, the MORE filtrate is pushed across the membrane.
Colloid osmotic pressure of plasma proteins in the glomerular blood, and capsular hydrostatic pressure exerted by fluids in the glomerular capsule, drive fluids back into the glomerular capillaries.
The net filtration pressure equals glomerular hydrostatic pressure minus colloid osmotic pressure of glomerular blood plus capsular hydrostatic pressure.
In addition to the renin-angiotensin mechanism, the renal cells produce other chemicals. Name five, and briefly give the main function of each
Answer: Renal cells also produce chemicals, some of which act locally as signaling molecules. These chemicals include prostaglandins (vasodilators and vasoconstrictors), which probably regulate GFR; nitric oxide, a potent vasodilator produced by the vascular endothelium;
adenosine, which constricts renal vasculature; and
endothelin, a vasoconstrictor that inhibits renin release.
where does the Filtration and monitoring of blood plasma take place and what does it form?
happens in kidneys; forms urine
how is the composition of urine and blood plasma different?
plasma has protein, urine contains wastes and ions
what are the next two places urine goes upon leaving the kidneys
ureters (muscular tubes) and urinary bladder (for temporary storage)
what are the functions of the urinary system?
1. responsible for water/electrolyte balance, excretion of toxic compounds,
2. reabsorption of important nutrients,
3. stimulation of rbc,
4. conversion of vitamin d to active form,
5. production of urine
what happens in reabsorbtion?
the filtrate flows through a series of tubules and 99% is returned to the blood
what happens in secretion?
as the filtrate passes through the tubules, additional substances pass into it from the blood.
where is the bladder located?
men-anterior to rectum.
women-anterior to the vagina and anteroinferior to the uterus
If the GFR is too low, needed substances may pass so quickly through the renal tubules that they are not absorbed and instead are lost in the urine.
In the kidneys, the countercurrent mechanism involves the interaction between the flow of filtrate through the loop of Henle 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.
Water reabsorption through the proximal convoluted tubule is termed obligatory water reabsorption, whereas water reabsorption through the distal convoluted tubule is termed facultative water reabsorption.
In the absence of hormones, the distal tubule and collecting ducts are relatively impermeable to water.
The "tube" that carries urine from the urinary bladder to the outside world is the ____________ and the "tube" that carries urine from the kidney to the urinary bladder is the _____________.
The urinary bladder is made up of ________ smooth muscle layers and may contain _______ milliliters of __________ when moderately full.
ndicate the correct order in which the filtrate flows through the following structures of the nephron.
-loop of Henle
Starting at the apex of a medullary pyramid, which is the correct sequence of structures through which urine flows to reach the exterior of the body?
The filtrate forced through the capillary walls in the kidneys enters which of the following structures first?
The bladder wall contains three layers of smooth muscle, collectively known as the ____, and its mucosa consists of ____.
detrusor muscle; transitional epithelium
The regulation of blood pH, by the elimination of excess acids or alkaline substances from the body, is accomplished by the:
Which of the following is normally present in the filtrate forced from the glomerular capillaries but does not normally appear in the urine?
Which of the following substances enters the renal tubule by both filtration and secretion?
Which of the following substances is not normally found in urine, and thus, if present, suggests a problem?
Red blood cells.