Urinary System
characteristic of the ascending limb of the nephron loop
1. osmolarity of filtrate decreases as it passes through 2. impermeable to water 3. permeable to solutes
characteristic of the descending limb of the nephron loop
1. osmolarity of filtrate increases as is passes through 2. permeable to water 3. impermeable to solutes
Place the segments of the renal tubule of a nephron in the correct order, with the region closest to the glomerulus at the top.
1. proximal tubule 2. nephron loop 3. distal tubule
A kidney is approximately ______ centimeters long, 6 centimeters wide, and 3 centimeters thick.
12
As filtrate passes through the renal tubule, __________ % of the filtrate is reabsorbed.
99
What makes up the renal lobe?
A renal pyramid and the cortex above
Which of the following forces oppose glomerular filtration? -Net filtration pressure (NFP) -Glomerular hydrostatic pressure (HPg) and capsular hydrostatic pressure (HPc) -Blood colloid osmotic pressure (OPg) and glomerular hydrostatic pressure (HPg) -Capsular hydrostatic pressure (HPc) and blood colloid osmotic pressure (OPg)
Capsular hydrostatic pressure (HPc) and blood colloid osmotic pressure (OPg)
Reabsorption of sodium, water, and secretion of hydrogen and potassium ions
Distal convoluted tubule
What is the definition of renal filtration?
Fluid leaves the glomerulus and enters the Bowman's (glomerular) capsule.
What describes the process of reabsorption in the kidneys?
Movement of substances from renal tubules into the peritubular capillaries
What describes the process of renal secretion?
Movement of substances from the peritubular capillaries to the nephron tubules
When the renal plasma threshold for glucose is reached, which of the following occurs?
Some glucose is secreted in the urine
Why is glucose found in the urine of diabetics?
The active transport mechanism in the renal tubule can't keep up with the amount of glucose in the tubular fluid.
What determines the composition of urine? Multiple choice question.
The ratio of water and solutes eliminated to maintain internal environment.
What is a glomerulus?
a tangled cluster of blood capillaries
This type of transport, with the help of ATP, allows a substance to be reabsorbed against its concentration gradient.
active
The __________ arteriole has a larger diameter, ensuring adequate pressure for filtration to occur within the renal corpuscle.
afferent
When systemic blood pressure decreases, the result is that the __________ arterioles change diameter by undergoing __________.
afferent; vasodilation
Describe the vasa recta
capillary beds within renal medulla
Glomerular filtrate collects in the ________ before entering the first portion of the renal tubule, called the __________
capsular space, proximal tubule
The rate at which the kidneys remove a substance from plasma is called renal _______
clearance
Tubular fluid leaves the nephron and flows into the __________. If the body needs to conserve water, the blood levels of the hormone ADH will ________ causing more water to be reabsorbed. The remaining filtrate is now called _______
collecting duct, increase, urine
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(n) __________ in the net filtration pressure.
decrease
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
Which limb of the nephron loop is permeable to water but not solutes?
descending limb
Reabsorption of only water
descending limb of the nephron loop
The proximal tubule reabsorbs ______ as the distal tubule.
different substances
Metabolism requires nutrients from the diet to be processed, which is done by the _________ system.
digestive
Fluid in the __________ would flow into a collecting duct.
distal tubule
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
Kidney transplantation is typically necessary for __________.
end stage renal failure
The kidneys serve additional functions, including the production of the hormone ______ that regulates red blood cell production.
erythropoietin
During the first step of urine formation, the material that enters the glomerular capsule is called glomerular ______.
filtrate
The fluid that leaves the glomerulus and enters the glomerular capsule is called glomerular _______
filtrate
The process by which blood pressure forces fluid through the glomerular capillary walls into the glomerular capsule is called glomerular ________
filtration
Three processes involved in urine formation are glomerular________ , tubular ______ , and ________ secretion.
filtration, reabsorption, tubular
In which direction do substances move during tubular reabsorption?
from the tubular fluid into the peritubular capillaries
Receives the plasma filtrate
glomerular capsule
If someone's renal clearance is abnormally low, it might indicate which type of condition?
glomerular damage
Fluid initially filtered from the blood and found in the glomerular capsule is called ______.
glomerular filtrate
The process by which the glomerular capillaries filter plasma is called
glomerular filtration
Urine formation begins with a process called ______, in which water and other small dissolved molecules and ions are moved from the glomerular capillary plasma into the glomerular capsule.
glomerular filtration
Which three processes are involved in the formation of urine?
glomerular filtration tubular reabsorption tubular secretion
Filtration of fluids and solutes from plasma
glomerulus
The renal corpuscle consists of a capillary bed called the _______ and a capsule of epithelial cells.
glomerulus
In glomerular filtration, substances move from the ______ into the ______.
glomerulus; nephron
The interstitial fluid within the medulla has a __________ osmolarity than the interstitial fluid within the cortex.
higher
The __________ of blood forces water and solutes out of the blood and into the capsule.
hydrostatic pressure
An increase in the net filtration pressure (NFP) would result in a(n) __________ in the GFR.
increase
Regulating the volume and composition of body fluids is the primary function of the ______.
kidneys
The bean-shaped organs that are reddish-brown in color and have a smooth surface are the _____
kidneys
The organs that function to regulate the removal of excess water, electrolytes, and metabolic wastes from body fluids are called the
kidneys
A substance that is freely reabsorbed down its concentration gradient must be ______-soluble.
lipid
If ADH levels are ______, less water will be reabsorbed and the volume of urine will ______.
low; increase
Urine flows from the ______ into the renal pelvis, and from there into the ureter.
major calyces
The major regions of the kidney are the renal _____ and the renal _____.
medulla, cortex
Urine passes from the collecting ducts into the ______ calyces, then into the ________ calyces before reaching the renal pelvis.
minor, major
If ADH levels are high, ______ water will be reabsorbed and ______ water will be excreted in the urine.
more; less
The structure that consists of a renal corpuscle and its associated renal tubule is called a(n)
nephron
what is the functional unit of the kidney
nephron
After flowing through the proximal tubule, fluid enters the _________ which extends toward the renal papilla.
nephron loop
Identify the three main parts of a renal tubule.
nephron loop, proximal tubule, and distal tubule
The functional units of the kidneys, responsible for filtration of the blood, are the
nephrons
Which is the term for the functional units of the kidneys, responsible for urine production?
nephrons
Where are the kidneys located in the human body?
on either side of the vertebral column
Filtration is a(n) __________ process that depends on a __________ gradient.
passive; pressure
The kidneys are on the ______ wall.
posterior abdominal
Inactivating the sodium-glucose symport SGLT2 inhibits the reabsorption of glucose by __________.
preventing glucose from entering the tubular cells
Consider the order of segments of the renal tubule. What is the first part of the renal tubule called?
proximal tubule
Leading away from the capsular space, glomerular filtrate first enters the ______.
proximal tubule
The process that returns substances to the internal environment, back into the extracellular fluid, is called tubular _________
reabsorption
Which are the two major components of a nephron?
renal corpuscle and renal tubule
The _______ is the layer that contains the capillary beds that function to filter the blood, called _____ Most renal tubules are also located in this layer.
renal cortex, glomeruli
The ________ is the layer that contains the descending and ascending limbs of the ______ that function in water and sodium reabsorption.
renal medulla, nephron loop
The ________ is the hollow portion of the kidney, filled with vessels, the renal calyces, and the renal pelvis.
renal sinus
The kidneys help in blood pressure regulation by altering the volume of urine produced and by producing the enzyme________ which catalyzes the production of angiotensin I.
renin
The kidneys are located __________.
retroperitoneally
Movement of certain substances from the peritubular capillaries into the renal tubules is called tubular ______
secretion
Renin is released in response to __________ stimulation.
sympathetic
ACE inhibitors are prescribed to control blood pressure. These drugs work by reducing __________.
the conversion of angiotensin I to angiontensin II
Glomerulosclerosis results in a __________ of the basement membrane.
thickening
What is the process by which substances move out of the peritubular capillary and move into the renal tubule?
tubular secretion
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
The byproduct of amino acid catabolism in the liver that is excreted in urine is ______.
urea
The body relies on the _________ system to remove the metabolic waste. This system will also keep the internal environment constant, which is known as _________
urinary, homeostasis.
The kidneys function to maintain normal body fluid composition and pH by adjusting the composition of the ____________ being produced.
urine
What type of capillary bed forms a relatively straight capillary loop in the renal medulla?
vasa recta
The kidneys activate________ which then helps in the absorption of calcium from the digestive tract.
vitamin D
The composition of urine reflects the ratio of solutes to ______ being eliminated by the kidneys.
water
List the urine-producing structures in the correct order.
1.Glomerular capsule 2.Proximal tubule 3.Nephron loop 4.Distal tubule 5.Collecting duct
Selective reabsorption of sodium, potassium, and chloride ions
Ascending limb of nephron loop
All substances filtered from the blood by the nephron are excreted in the urine. T/F
False
True or false: All segments of the renal tubule reabsorb the same substances.
False
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
Reabsorption of nutrients, glucose, various ions, and water
Proximal convoluted tubule
The process requires oxygen and produces carbon dioxide, which are exchanged with the atmosphere through the _______ system. But carbon dioxide is not the only waste product of these chemical processes.
respiratory
Water is able to leave the tubular fluid of _______ the segment of the nephron loop, following its osmotic gradient.
thin
As the fluid flows through the renal tubules, useful substances are removed and sent back to the blood. This is called _________, and largely takes place in the __________. Unwanted substances are moved from the blood of _________ into the renal tubule in a process called _________
tubular reabsorption, proximal tubules, peritubular capillaries, tubular secretion
The waste product produced by amino acid catabolism, and excreted from the body through urine, is
urea
Urine formation begins with the process of ________, in which substances are forced out of capillaries called a(n) ________ and into the nephron at the ________. This fluid, called filtrate, has the same composition as blood plasma, except for larger molecules, such as ________, which cannotfit through the glomerular pores.
filtration, glomerulus, glomerular capsule, proteins
Inhibiting the sodium-glucose symport SGLT2 is expected to cause a(n) __________ in the osmolarity of the tubular filtrate, and would thus __________ the risk of dehydration.
increase; increase