urinary sustem final 2

A patient has an abnormally high concentration of protein in their urine. What does this most likely indicate?

Increased glomerular permeability due to damage

Which of the following would be the least likely consequence of removing one kidney in a healthy adult?

Decreased urine output

A blockage in the efferent arteriole of a nephron would most likely result in:

Increased pressure and filtration rate within the glomerulus

The ability of the kidneys to produce concentrated urine is primarily dependent on:

The juxtamedullary nephrons and their long loops of Henle

If the peritubular capillaries were damaged, which of the following functions would be most impaired?

Reabsorption of water and solutes

A patient presents with abnormally alkaline urine. Which of the following is a possible explanation?

Bacterial infection of the urinary tract

In a state of severe dehydration, which of the following responses is expected?

Increased permeability of the collecting duct to water

If a patient had damage to the renal medulla, which function might be most impaired?

Production of concentrated urine

Which of the following is NOT part of the filtration membrane in the glomerulus?

Peritubular capillary wall

Which change would most likely lead to an increase in glomerular filtration rate (GFR)?

Constriction of the efferent arteriole

Which of the following best explains what happens when perirenal fat is significantly depleted?

Risk of nephroptosis due to lack of kidney support

Which structure receives blood directly from the afferent arteriole?

Glomerulus

Which is TRUE regarding the role of the juxtaglomerular apparatus (JGA)?

It senses blood pressure and sodium levels, stimulating renin release.

Which feature allows podocytes in the glomerulus to contribute to filtration?

Filtration slits between foot processes

The vasa recta is important primarily for:

Maintaining osmotic gradient in the renal medulla

What is the best explanation for why the kidney receives about 25% of cardiac output?

It continuously filters a large volume of blood plasma.

Which intrinsic mechanism allows the nephron to maintain constant GFR despite changes in blood pressure?

Myogenic response in afferent arteriole smooth muscle

Which cells in the nephron regulate acid-base balance and are located in the collecting duct?

Intercalated cells

What occurs if GFR is too high?

Needed substances are lost in the urine.

Which portion of the nephron is responsible for reabsorbing the majority of filtered sodium and water?

Proximal convoluted tubule (PCT)

Which is an example of secondary active transport in the nephron?

Sodium-glucose cotransport in the proximal tubule

A patient has a renal clearance of a substance measured at 150 mL/min. What does this most likely indicate?

The substance is secreted.

When is urine considered acidic?

During prolonged fasting or high-protein diets

What mechanism primarily helps the kidney concentrate urine by maintaining a gradient in the medulla?

Countercurrent multiplication

Which structure reabsorbs water in response to ADH, but only when it is present?

Collecting duct

Which of the following is NOT a function of the kidney?

Produces bile

Which condition can occur when perirenal fat is depleted?

Nephroptosis

What is the correct order of renal blood flow starting from the renal artery?

Renal artery → Afferent arteriole → Glomerulus → Efferent arteriole

Constriction of the afferent arteriole causes:

Decreased GFR

Which nephron type has a long loop of Henle and concentrates urine?

Juxtamedullary nephron

Podocytes are located in which part of the nephron?

Bowman’s capsule

Which cells are responsible for reabsorbing water and sodium in the collecting duct?

Principal cells

Why does the kidney receive a large fraction of the cardiac output?

To filter large volumes of blood

Where does filtration occur in the nephron?

Bowman’s capsule

What is the role of the juxtaglomerular apparatus?

Regulates blood pressure and filtration

Which part of the nephron reabsorbs about 65% of sodium and water?

Proximal tubule

What force drives filtration across the glomerular membrane?

Hydrostatic pressure

Which mechanism describes the kidney’s ability to regulate its own GFR in response to blood pressure changes?

Myogenic mechanism

Which hormone increases water reabsorption in the collecting ducts?

ADH

Which part of the nephron is impermeable to water and actively transports sodium?

Ascending limb

What does a renal clearance <125 mL/min suggest?

Substance is reabsorbed

Which of the following is NOT a function of the kidney?

Secretes insulin into blood

Where are the kidneys located

Retroperitoneally along the posterior abdominal wall

What could happen if perirenal fat is lost?

Kidney drop and dysfunction (nephroptosis)

What is the function of the hilum of the kidney?

Where nerves, blood vessels, and ureters enter/exit

Which region is the outer portion of the kidney responsible for filtration?

Renal cortex

What is the difference between afferent and efferent arterioles?

Afferent enters the glomerulus; efferent exits

What effect does constriction of the afferent arteriole have?

Decreased GFR and reduced filtration pressure

What are vasa recta?

Long, straight capillaries near juxtamedullary nephrons

What distinguishes cortical from juxtamedullary nephrons?

Juxtamedullary nephrons have long loops for concentrated urine

What are podocytes and where are they located?

Cells that wrap glomerular capillaries to help filtration

Which cells are found in the collecting duct and help with pH balance?

Intercalated cells

Why is the nephron structure important to mineral and pH regulation?

Different segments regulate ion transport and acid-base balance

Why is the kidney a sensor of hypoxia?

It detects low oxygen and releases erythropoietin

What are the 3 major steps of urine formation?

Filtration, Reabsorption, Secretion

Where does filtration occur in the nephron?

Bowman’s capsule

What is the function of the juxtaglomerular apparatus (JGA)?

Detect blood sodium and pressure; regulate GFR

What is the intrinsic myogenic mechanism of GFR control?

Afferent arteriole stretches and constricts in response to BP

What is tubuloglomerular feedback?

Macula densa senses high NaCl and lowers GFR

Which hormone is not involved in extrinsic control of GFR?

Insulin

What forms the filtration membrane?

Podocytes, capillary endothelium, and basement membrane

Which force dominates filtration at the glomerulus?

Hydrostatic pressure

Why do we only excrete about 1–2 liters of urine when we filter 150–180 liters of plasma per day?

Kidneys reabsorb most filtered water

What is the main role of the ascending limb of the loop of Henle?

Actively pumps sodium out and is impermeable to water

What is reabsorbed in the proximal convoluted tubule (PCT)?

Water, Na+, glucose, amino acids, bicarbonate

What gets reabsorbed in the descending limb of the loop of Henle?

Water

What gets reabsorbed in the distal convoluted tubule (DCT)?

Na+ and Ca2+ (regulated by hormones)

What hormone increases reabsorption of Na+ in the DCT and collecting duct?

Aldosterone

What is secreted in the nephron during tubular secretion

H+, K+, creatinine, drugs

When is urine acidic?

During high protein intake or acidosis

How is urine osmolality linked to blood osmolality?

Blood and filtrate move in opposite directions to concentrate urine

How does the kidney respond to overhydration?

Dilutes urine and reduces ADH

What does a renal clearance of <125 mL/min indicate?

Substance is reabsorbed

What does a renal clearance >125 mL/min indicate?

Substance is secreted

Substance is secreted

Clear to pale yellow, slight odor, pH 4.5–8