The glomerulus together with the cup-shaped capsule that surrounds it forms which structure?
Renal corpuscle
✓
Renal pyramid
Renal column
Renal calyx
Correct Answer
Renal corpuscle
The renal corpuscle is the filtering part of the nephron, made of the glomerular capillary tuft and Bowman's capsule. Renal pyramid describes a cone of medullary tissue that holds tubules and collecting ducts. Renal column is cortical tissue that extends between pyramids. Renal calyx is a cup-shaped space that collects urine draining from the pyramids.
Category: Nephron and Filtration
Question 2
Which cells of the inner capsule layer wrap the glomerular capillaries with foot processes that form filtration slits?
Mesangial cells
Podocytes
✓
Macula densa cells
Juxtaglomerular cells
Correct Answer
Podocytes
Podocytes extend foot processes around the capillaries, and the slits between them are the last barrier that keeps plasma proteins out of the filtrate. Mesangial cells sit between capillaries and change the filtering surface area. Macula densa cells line the distal tubule and sense sodium chloride. Juxtaglomerular cells in the arteriole walls release renin.
Category: Nephron and Filtration
Question 3
Which nephron segment has a brush border of microvilli that greatly enlarges its surface for reabsorption?
Descending limb of the loop
Distal convoluted tubule
Proximal convoluted tubule
✓
Collecting duct
Correct Answer
Proximal convoluted tubule
The proximal convoluted tubule is the longest nephron segment, and its microvilli give it the surface needed to reclaim most of the filtered water, sodium and nutrients. Descending limb of the loop is thin and lined with flat cells that mainly let water out. Distal convoluted tubule cells lack microvilli. Collecting duct fine-tunes water and sodium under hormonal control.
Category: Nephron and Filtration
Question 4
Which group of tubule cells senses the amount of sodium chloride arriving at the start of the distal tubule and helps adjust GFR?
Podocyte layer
Vasa recta
Renal papilla
Macula densa
✓
Correct Answer
Macula densa
Macula densa cells, part of the juxtaglomerular apparatus, detect sodium chloride delivery and signal the afferent arteriole and the renin-releasing cells. Podocyte layer forms filtration slits in the capsule. Vasa recta are capillaries around the loops of juxtamedullary nephrons. Renal papilla is the tip of a pyramid where urine drains into a calyx.
Category: Renal Regulation
Question 5
A patient with advanced chronic kidney disease develops anemia. Loss of which kidney hormone best explains it?
Erythropoietin
✓
Renin
Aldosterone
Calcitonin
Correct Answer
Erythropoietin
Cells in the renal cortex release erythropoietin when tissue oxygen falls, and it stimulates the bone marrow to make red blood cells, so diseased kidneys that make too little lead to anemia. Renin starts the renin-angiotensin system and does not drive red cell production. Aldosterone comes from the adrenal cortex and controls sodium. Calcitonin is a thyroid hormone that lowers blood calcium.
Category: Renal Regulation
Question 6
When systemic blood pressure rises, how does the myogenic response keep GFR steady?
The afferent arteriole dilates
The afferent arteriole constricts
✓
The efferent arteriole dilates
The glomerular capillaries leak protein
Correct Answer
The afferent arteriole constricts
Stretch of the smooth muscle in the afferent arteriole makes it constrict, which limits the rise in glomerular pressure and holds filtration near normal. The afferent arteriole dilates when pressure falls, not when it rises. The efferent arteriole dilating would lower glomerular pressure but is not the myogenic mechanism. The glomerular capillaries leak protein only when the filter is damaged.
Category: Renal Regulation
Question 7
Which hormone, released when the atrial walls are stretched by excess blood volume, increases GFR and sodium excretion?
Antidiuretic hormone
Angiotensin II
Atrial natriuretic peptide
✓
Aldosterone
Correct Answer
Atrial natriuretic peptide
Atrial natriuretic peptide dilates the afferent arteriole and opposes sodium retention, so urine output rises and blood pressure falls. Antidiuretic hormone conserves water. Angiotensin II constricts arterioles and promotes sodium retention. Aldosterone increases sodium reabsorption in the distal nephron.
Category: Renal Regulation
Question 8
Acute kidney injury caused by severe hemorrhage that reduces blood flow to otherwise healthy kidneys is classified as which type?
Intrarenal
Postrenal
Congenital
Prerenal
✓
Correct Answer
Prerenal
Prerenal injury starts before the kidney, when poor perfusion from hemorrhage, shock, burns or heart failure starves the tubules of oxygen. Intrarenal injury starts within kidney tissue, such as damage from nephrotoxic drugs or glomerulonephritis. Postrenal injury comes from obstruction of urine flow below the kidney. Congenital describes a defect present from birth.
Category: Renal Disorders
Question 9
Which laboratory change is expected in fluid volume excess because the extra plasma dilutes the blood?
Decreased hematocrit
✓
Increased hematocrit
Increased serum osmolality
Increased urine specific gravity
Correct Answer
Decreased hematocrit
Extra plasma water spreads the same number of red cells through a larger volume, so the hematocrit falls; sodium, BUN and serum osmolality tend to fall as well. Increased hematocrit is the pattern seen with dehydration. Increased serum osmolality reflects concentrated blood, also typical of fluid deficit. Increased urine specific gravity reflects concentrated urine, while the urine in fluid excess is dilute.
Category: Fluid Volume Excess
Question 10
Which organism is the usual cause of pyelonephritis?
Staphylococcus aureus
Escherichia coli
✓
Candida albicans
Streptococcus pyogenes
Correct Answer
Escherichia coli
Escherichia coli from the bowel is the usual cause of urinary tract infections, including pyelonephritis, which typically climbs from the bladder up the ureter to the kidney. Staphylococcus aureus is a common cause of skin and wound infections. Candida albicans is a yeast that occasionally infects the urinary tract, usually in catheterized or immunosuppressed patients. Streptococcus pyogenes causes strep throat and skin infections.
Category: Renal Disorders
Question 11
Which cancer of the kidney is the most common kidney cancer in children and is typically first noticed as a painless swelling or mass in the abdomen?
Renal cell carcinoma
Neuroblastoma
Wilms tumor
✓
Transitional cell carcinoma
Correct Answer
Wilms tumor
Wilms tumor, or nephroblastoma, arises from embryonic kidney tissue and is the typical childhood kidney cancer; a parent often finds the painless abdominal mass, and some children also have hypertension. Renal cell carcinoma is the usual kidney cancer of adults. Neuroblastoma is a childhood tumor of nerve tissue that often starts in the adrenal gland. Transitional cell carcinoma arises in the lining of the renal pelvis, ureter or bladder, mainly in adults.
Category: Renal Disorders
Question 12
Which region of the brain contains the center that coordinates detrusor contraction with relaxation of the urinary sphincters during voiding?
Medulla oblongata
Hypothalamus
Cerebellum
Pons
✓
Correct Answer
Pons
The pontine micturition center in the pons coordinates bladder contraction with sphincter relaxation, while the cerebral cortex provides voluntary control over when voiding happens. Medulla oblongata controls breathing and heart rate. Hypothalamus regulates thirst, temperature and hormone release. Cerebellum coordinates movement and balance.
Category: Lower Urinary Tract
Question 13
Which description fits the internal urethral sphincter?
Smooth muscle under involuntary control
✓
Skeletal muscle under voluntary control
Skeletal muscle under involuntary control
Smooth muscle under voluntary control
Correct Answer
Smooth muscle under involuntary control
The internal urethral sphincter is a ring of smooth muscle where the urethra leaves the bladder, and it is controlled by the autonomic nervous system. Skeletal muscle under voluntary control describes the external urethral sphincter, supplied by the pudendal nerves. Skeletal muscle under involuntary control and smooth muscle under voluntary control do not describe either urethral sphincter.
Category: Lower Urinary Tract
Question 14
A woman reports leaking small amounts of urine whenever she coughs, sneezes or lifts something heavy. Which type of incontinence does this describe?
Urge
Stress
✓
Overflow
Functional
Correct Answer
Stress
Stress incontinence is leakage with a sudden rise in abdominal pressure when pelvic floor support is weak, as after childbirth, with obesity or with estrogen loss. Urge incontinence is a sudden strong need to void with leakage, caused by an overactive bladder muscle. Overflow incontinence is dribbling from a bladder that cannot empty because of obstruction. Functional incontinence occurs when the urinary tract works but the person cannot reach the toilet in time.
Category: Incontinence and UTI
Question 15
An older adult with severe arthritis and an intact urinary tract cannot get to the bathroom in time and has episodes of wetting. Which type of incontinence is this?
Stress
Urge
Functional
✓
Overflow
Correct Answer
Functional
Functional incontinence comes from a problem outside the urinary system, such as limited mobility or cognitive impairment, while bladder and urethral function are normal. Stress describes leakage with coughing or sneezing from weak pelvic support. Urge describes leakage after a sudden strong need to void from an overactive bladder. Overflow describes dribbling from a bladder that cannot empty completely.
Category: Incontinence and UTI
Question 16
Which assessment tool records a patient's fluid intake, urine output and episodes of leakage over several days to help identify the type of incontinence?
Urodynamic study
Postvoid bladder scan
Urine culture
Voiding diary
✓
Correct Answer
Voiding diary
A voiding diary kept by the patient is one of the most useful tools for sorting out incontinence, because it shows the pattern of intake, voiding and leakage. Urodynamic study measures bladder pressure and flow in a testing lab. Postvoid bladder scan measures the urine left after voiding at one point in time. Urine culture identifies bacteria in an infection.
Category: Incontinence and UTI
Question 17
Most kidney stones are composed mainly of which substance?
Calcium
✓
Uric acid
Cystine
Struvite
Correct Answer
Calcium
Calcium stones, usually calcium oxalate, are the most common type, and risk rises with dehydration, hyperparathyroidism, immobility and a family history. Uric acid stones are less common and are linked to gout and high purine intake. Cystine stones are rare and result from an inherited amino acid disorder. Struvite stones are linked to certain urinary tract infections.
Category: Renal Disorders
Question 18
What is the backflow of urine from the bladder up into a ureter called?
Urinary retention
Vesicoureteral reflux
✓
Hydronephrosis
Overflow incontinence
Correct Answer
Vesicoureteral reflux
Vesicoureteral reflux lets bladder urine move back toward the kidney, which raises the risk of pyelonephritis; normally the way each ureter tunnels through the bladder wall acts as a valve. Urinary retention is inability to empty the bladder. Hydronephrosis is swelling of the renal pelvis from urine that cannot drain. Overflow incontinence is leakage from an overfilled bladder.
Category: Lower Urinary Tract
Question 19
Through which medial indentation do the renal artery, renal vein and ureter enter or leave the kidney?
Cortex
Capsule
Hilum
✓
Papilla
Correct Answer
Hilum
The hilum is the notch on the medial border of each kidney where blood vessels, lymphatics, nerves and the ureter pass. Cortex is the outer region of kidney tissue that holds the renal corpuscles. Capsule is the fibrous covering around the whole kidney. Papilla is the tip of a renal pyramid that drains urine into a calyx.
Category: Kidney Structure
Question 20
Low blood levels of which plasma protein, as in nephrotic syndrome, let fluid shift out of the vessels and worsen edema?
Fibrinogen
Hemoglobin
Myoglobin
Albumin
✓
Correct Answer
Albumin
Albumin creates most of the plasma oncotic pressure that holds water inside the capillaries, so heavy urinary loss of albumin lets fluid move into the tissues. Fibrinogen is a clotting protein with little role in oncotic pressure. Hemoglobin is carried inside red blood cells, not dissolved in plasma. Myoglobin is a muscle protein that appears in the blood after muscle injury.
Category: Fluid Volume Excess