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