BIO169 Chapter 26 Assessment
Click and drag each word or phrase on the left to complete the sentences on the right.
Production of urine by the (kidneys) begins to fill the urinary bladder. The fullness of the (urinary bladder) is detected by (stretch receptors) Sensory nerve impulses travel along the (pelvic nerve) to the (sacral) spinal cord. Efferent impulses excite the (detrusor muscle) and relax the (internal urethral sphincter.) Voiding of the bladder is delayed by the (voluntary) control of the (external urethral sphincter.)
Match the region of the kidney tubule with its description.
Site where the majority of reabsorption takes place.= proximal convoluted tubule Contains simple squamous epithelium in the thin segments.= loop of henle Permeability to water and solutes in this region varies based on hormone regulation.= distal convoluted tubule Amino acids are reabsorbed in this region.= proximal convoluted tubule
Indicate whether each of the following is a characteristic of the ascending limb or the descending limb of the nephron loop.
ascending limb= filtrate osmolarity decreases as it passes through, more permeable to solutes, and impermeable to water descending limb=filtrate osmolarity increases as it passes through and permeable to water
Which of the following forces oppose glomerular filtration?
capsular hydrostatic pressure (HPc) and blood colloid osmotic pressure (OPg)
Angiotensin II triggers the __________________________ of the intraglomerular mesangial cells which results in a/an _______________________________ of the filtration surface area.
contraction; decrease
If both the glomerular and capsular hydrostatic pressures remain unchanged, an increase in the blood colloid osmotic pressure results in a/an _____________ in the net filtration pressure.
decrease
The nephron loop is responsible for approximately 25% of the reabsorption of sodium. Loop diuretics cause an overall __________________ in the reabsorption of sodium in this region resulting in a/n ________________________ in the osmolarity of the tubular filtrate.
decrease; increase
Proteinuria occurs when the filtration membrane becomes leaky, allowing proteins to cross. This impacts the blood colloid osmotic pressure by ____________________ the osmolarity gradient between the blood and filtrate, thereby ________________ the strength of this pressure.
decreasing; reducing
The vasa recta is a specialized capillary that branches from the ___________ arteriole. The blood flow in the vasa recta runs _______________ to the flow of tubular filtrate within the nephron loop.
efferent; parallel, but in the opposite direction
Check all that are a function of the kidneys.
excretion, regulation of the concentration of solutes in the blood, regulation of blood volume and pressure, regulation of vitamin D synthesis, regulation of extracellular fluid pH, and regulation of red blood cell synthesis
Place the list of urinary system structures in order from the fewest to most numerous.
fewest to most numerous= 1. urinary bladder 2. kidney 3. major calyces 4. renal pyramids 5. collecting ducts 6. glomeruli 7. podocytes 8. tubular epithelial cells
Indicate the relative strength (highest to lowest, regardless of direction) for each of the pressures that contribute to the net filtration rate. Assume normal conditions.
highest=glomerular hydrostatic pressure mid=blood colloid osmotic pressure lowest=capsular hydrostatic pressure
An increase in the NFP would result in a(n) _______________ in the GFR.
increase
Indicate whether each of the following would increase or decrease filtration.
increase filtration=relaxation of the afferent arteriole, constriction of the efferent arteriole, and increase in blood volume decrease filtration=an increase in capsular pressure, an increase in plasma protein concentration, an obstruction in the proximal tubule, and severe dehydration
Inhibiting the sodium-glucose symport SGLT2 is expected to cause a/an __________________________ in the osmolarity of the tubular filtrate, and would thus _____________________ the risk of dehydration
increase; increase
Treatment with Probenecid® results in _________________ levels of uric acid in the urine and __________________ levels of uric acid in the blood.
increased; decreased
Select all that are characteristics of inulin, a substance used for renal function tests.
it freely passes through the filtration membrane, it is not metabolized or produced by the kidneys, and it is a polysaccharide.
Individuals with Bartter syndrome have a defective gene coding for Na+/K+/2Cl- symport (NKCC2) that disables it from functioning. These individuals are expected to have ___________ than normal blood potassium levels. This response is the ___________ what is expected from individuals taking prescribed loop diuretics.
lower; same as
Decreased Na+ and water reabsorption due to the use of loop diuretics and thiazides __________ the concentration gradient of the interstitial fluid, thereby _____________ the osmotic force at the collecting tubule and duct.
lowers; reducing
The majority of sodium reabsorption occurs at the proximal convoluted tubule. During this process sodium enters the tubule cells at the ___________________ and exits the tubule cells at the ____________________.
luminal membrane by facilitated diffusion; basolateral membrane through the sodium potassium pump
Which of the following substances utilizes paracellular transport in order to cross the basolateral membrane of the tubule cell during the process of reabsorption?
potassium
Inactivating the sodium-glucose symport SGLT2 inhibits the reabsorption of glucose by
preventing glucose from entering the tubular cells.
Under normal conditions, the majority of uric acid reabsorption occurs at the _______________________.
proximal convoluted tubule
Antidiuretic hormone enhances water ______________ by _______________ the number of aquaporins at the tubular cell membrane.
reabsorption; increasing
List the tissue layers of the urinary bladder from the most interior cell type or tissue layer to the final exterior layer.
1=transitional epithelium 2=lamina propria 3=detrusor muscle 4=adventitia
Indicate whether each of the following substances is reabsorbed from the filtrate or secreted into the filtrate.
secreted=NH4, penicillin, H+ reabsorbed=glucose, water, Mg2, HCO3, and amino acids
In addition to enhancing the reabsorption of sodium, aldosterone also enhances the __________________ of potassium.
secretion
Classify the following activities with regard to whether they are major functions that are directly performed by the urinary system.
function=elimination of toxins, regulation of blood volume, regulation of pH levels, regulation of vitamin D synthesis, regulation of blood ion concentrations, regulation of red blood cell synthesis, and secretion of erythropoietin not a function=removal of unwanted proteins, production of bile, and storage of nutrients such as glucose
The interstitial fluid within the medulla has a __________________ osmolarity than the interstitial fluid within the cortex.
higher
Place each of the labels in the proper position to denote whether they would pass through the filtration membrane or not.
pass through filtration membrane=sodium, water, glucose, creatinine, and urea cannot pass through=a protein 4 nm in diameter, red blood cells, large amounts of albumin, antibodies (12 nm in diameter), and hormone bound to transport protein
Filtration is a/an __________ process that depends on a __________ gradient.
passive; pressure
Renin is released in response to ________________________ stimulation
sympathetic
Indicate whether each statement is true or false regarding the regulation of the glomerular filtration rate.
1. Regulation is achieved through autoregulation.= true 2. The myogenic mechanism involves smooth muscles in the arterioles acting as stretch receptors, thus dilating or constricting the arteriole in response to changes in blood pressure.= true 3. The myogenic mechanism involves macula densa cells sending signals to the juxtaglomerular cells to either constrict or dilate the arteriole.= false 4. The tubuloglomerular feedback mechanism involves smooth muscles in the arterioles acting as stretch receptors, thus dilating or constricting the arteriole in response to changes in blood pressure.= false 5. The tubuloglomerular mechanism involves macula densa cells sending signals to the juxtaglomerular cells to either constrict or dilate the arteriole.= true
Place the statements in the correct order to illustrate the role of ADH in regulating extracellular volume.
1. blood pressure greatly increases 2. ADH secretion is inhibited 3. reabsorption of water in kidney tubules is decreased 4. urine volume is increased 5. blood pressure and extracellular fluid volume is decreased
Correctly complete the sentences below by choosing the appropriate terms.
Aging causes the kidneys to gradually decrease in (size), apparently in association with (blood vessel) changes. Blood flowing through the kidneys gradually decreases by about 10% decrease per year as (arterioles) become irregular and twisted and glomeruli are lost. By age 80, 40% of the glomeruli are not functioning. Some lack blood flow, and others become impermeable. Ducts also become thicker, shorter, and more irregular in structure, and there are losses in secretion and (reabsorption.) Water retention by (urine concentration) declines, increasing risk for dehydration. The ability to eliminate wastes and toxins from the blood also decreases. The kidney decreases renin secretion, and has a reduced ability to participate in vitamin D synthesis, which contributes to (Ca²⁺ deficiency,) osteoporosis, and bone fractures. Recall that (one-third) of one kidney is required to maintain homeostasis, and additional kidney tissue constitutes a (reserve capacity.) Therefore, the age-related changes in the kidney reduce the kidney's (reserve capacity.)
Select the correct word to complete each sentence.
Most water and NaCl reabsorption takes place in the (proximal convoluted tubule) In the thin segment of the descending loop of Henle, filtrate concentration is (equal) to interstitial fluid concentration. The ascending loop of Henle is (impermeable) to water. Solutes pass (out of) the ascending loop of Henle via diffusion or transport mechanisms. Water and NaCl are (reabsorbed) at the distal convoluted tubules and collecting ducts. As the filtrate travels through the ascending loop of Henle, its concentration is (reduced)
Complete each statement by using the appropriate word or phrase from the list.
Negatively charged proteoglycans found in the (basement membrane) prevent most proteins in the blood from exiting the glomerular capillaries. Filtrations slits are formed by (podocytes.) Small openings in the capillary endothelium called (fenestrae) are too small to allow cells to leave the glomerulus. The volume of blood that enters the afferent arteriole is not equal to the volume of blood that travels through the efferent arteriole due to the process termed (glomerular filtration.) A kidney infection or injury that results in damage to the (filtration membrane) may result in proteinuria (protein in the urine).
Indicate the pathway of urine formation to urine output by placing each of the structures in the correct sequential order from left to right.
Nephron, collecting tubule, collecting duct, papillary duct, minor calyx, major calyx, renal pelvis, ureters, bladder, then urethra
Correctly label the following components of the urinary system.
ON DESKTOP AND SCREENSHOTS
Select all that are true regarding the use of PAH to determine renal plasma flow.
PAH can pass through the filtration membrane and PAH is efficiently secreted into the kidney tubules, leaving little of it left in the blood
Correctly label the following anatomical structures of the female urinary system and associated structures.
PICTURE ON PHONE
Glomerulosclerosis results in a ____________________ of the basement membrane.
thickening
The total amount of a substance that passes through the filtration membrane into the nephrons each minute is called the __________.
tubular load
Tubular reabsorption and tubular secretion differ in that
tubular secretion adds materials to the tubular filtrate while tubular reabsorption removes materials from the tubular filtrate.
Pendrin is found in __________ intercalated cells where it allows for the ________________ of bicarbonate.
type B; secretion
The expected response to metabolic alkalosis is the ___________________ of Pendrin. Type _____________ also assist in buffering the alkaline blood through its transport of H+.
upregulation; B
Insert the correct word to complete each sentence.
Filtration involves the movement of materials across the filtration membrane into the (Bowman capsule.) Solutes are reabsorbed across the wall of the nephron by (transport processes.) Water is reabsorbed across the wall of the nephron by (osmosis.) Water and solutes that are reabsorbed across the wall of the nephron enter the (peritubular capillaries.) Tubular secretion involves the secretion of water and solutes across the wall of the nephron (into) the filtrate.
Complete each statement by using the appropriate word or phrase from the list.
The countercurrent multiplier is a phenomenon that occurs in the (nephron loop) Countercurrent exchange occurs as both solutes and water move freely in and out of the (vasa recta.) The increase in filtrate osmolarity as it flows down the descending limb is due to (water) moving out of the tubule. The decrease in osmolarity of the filtrate as it flows up the ascending limb is due to (solutes) moving out of the tubule. The osmolarity of the filtrate is virtually the same at the entrance and exit of the (vasa recta.) The osmolarity of the filtrate is approximately 100 mOsm/L at the end of the (ascending limb) and around 1200 mOsm/L at the end of the (descending limb.) The recycling of (urea) out of the collecting duct and back into the nephron loop contributes significantly to the medullary osmotic gradient.
Complete each statement by using the appropriate word or phrase from the list
The process of (renal autoregulation) is the ability of the kidneys to maintain a relatively constant GFR. The process whereby the flow of filtrate through the distal tubule results in changes in GFR is termed (tubuloglomerular feedback.) The three components of the (juxtaglomerular apparatus) are the JG cells, the macula densa, and the mesangial cells. Epithelial cells found where the distal tubule passes between the afferent and efferent arterioles comprise the (macula densa) The afferent arteriole contains cells called (juxtaglomerular cells) that secrete the enzyme renin. The afferent arteriole reflexively contracts in response to a rise in blood pressure, thus preventing a rise in GFR. This form of regulation is called the (myogenic mechanism) An increase in the rate of filtrate flow through the distal tubule results in contraction of the (afferent arteriole) and a decrease in GFR. When blood pressure drops, renin is released into the blood, resulting in an increase in the hormone (angiotensin II), which acts to decrease GFR while simultaneously raising blood pressure.
Complete each sentence regarding urine formation.
There are four major stages in the (formation) of urine. The first stage involves creating a filtrate in the (glomerulus.) Second, the filtrate flows through the tubules and useful substances are (reabsorbed.) Additionally, waste products are (secreted) by the tubules. If blood volume or blood pressure is low, the last stage of urine formation includes water (conservation) in the collecting duct.
When systemic blood pressure decreases, the result is that the __________ arterioles change diameter by undergoing __________.
afferent; vasodilation
Glucose that is reabsorbed into tubular cells travels __________ its concentration gradient through sodium-glucose symport channels at the luminal membrane. Glucose in tubular cells exits the basolateral membrane into interstitial fluid through the process of ______________________.
against; facilitated diffusion
Aldosterone enhances the reabsorption of sodium through the upregulation of the sodium-potassium pump found at the ________________.
basolateral membrane
ACE inhibitors are prescribed to control blood pressure. These drugs work by reducing
the conversion of angiotensin I to angiotensin II
Check all that occur to the kidneys as a result of aging.
the kidneys decrease in size, blood flow through the kidneys decrease, and the kidneys become less responsive to ADH and aldosterone
Indicate whether each of the following would result in a more dilute urine or a more concentrated urine.
would result in a more concentrated urine=working outside on a hot day without access to drinking water, overexpression of aquaporins, and increasing the permeability of the collecting duct to water. would result in a more dilute urine= drinking a larger volume of water on a day when you rested and stayed inside, overdosing on losartan, overproduction of aldosterone, and a new virus that attacks, damages the pituitary gland, and drinking beverages containing alcohol or caffeine.
