Q.1 Which of the following is the functional unit of the kidney?
Neuron
Nephron
Glomerulus
Lobule
Explanation - The nephron is the structural and functional unit of the kidney responsible for urine formation.
Correct answer is: Nephron
Q.2 Where are the kidneys located in the body?
Thoracic cavity
Pelvic cavity
Retroperitoneal space
Peritoneal cavity
Explanation - The kidneys are located retroperitoneally on either side of the vertebral column.
Correct answer is: Retroperitoneal space
Q.3 Which blood vessel supplies blood to the kidneys?
Renal artery
Hepatic artery
Aortic arch
Mesenteric artery
Explanation - The renal arteries branch off the abdominal aorta to supply blood to the kidneys.
Correct answer is: Renal artery
Q.4 Which structure collects urine from the renal pyramids?
Renal pelvis
Minor calyx
Ureter
Loop of Henle
Explanation - Urine from the renal pyramids drains into the minor calyces, then major calyces, and finally the renal pelvis.
Correct answer is: Minor calyx
Q.5 What is the primary function of the urinary system?
Hormone production
Excretion of waste products
Digestion of proteins
Oxygen transport
Explanation - The urinary system removes nitrogenous wastes and maintains fluid and electrolyte balance.
Correct answer is: Excretion of waste products
Q.6 Which part of the nephron is primarily responsible for filtration?
Loop of Henle
Glomerulus
Collecting duct
Distal tubule
Explanation - Filtration of blood occurs in the glomerulus, forming the filtrate that enters the renal tubule.
Correct answer is: Glomerulus
Q.7 Which structure connects the kidney to the urinary bladder?
Urethra
Ureter
Renal pelvis
Renal vein
Explanation - The ureters are muscular tubes that transport urine from the kidneys to the bladder.
Correct answer is: Ureter
Q.8 What type of epithelium lines the urinary bladder?
Simple squamous
Stratified squamous
Transitional
Cuboidal
Explanation - Transitional epithelium allows the bladder to stretch and recoil as it fills and empties.
Correct answer is: Transitional
Q.9 Which hormone regulates water reabsorption in the kidneys?
ADH
Insulin
Aldosterone
Glucagon
Explanation - Antidiuretic hormone (ADH) increases water reabsorption in the collecting ducts.
Correct answer is: ADH
Q.10 What is the outermost layer of the kidney called?
Renal medulla
Renal cortex
Renal capsule
Renal pelvis
Explanation - The renal capsule is the fibrous outer covering of the kidney.
Correct answer is: Renal capsule
Q.11 Where does urine formation begin in the nephron?
Collecting duct
Bowman's capsule
Loop of Henle
Distal tubule
Explanation - Urine formation begins with filtration in Bowman's capsule, surrounding the glomerulus.
Correct answer is: Bowman's capsule
Q.12 Which of the following is NOT a function of the kidneys?
Excretion of urea
Regulation of blood pressure
Production of erythropoietin
Production of insulin
Explanation - Insulin is produced by the pancreas, not the kidneys.
Correct answer is: Production of insulin
Q.13 The renal pyramids are located in which part of the kidney?
Cortex
Medulla
Pelvis
Capsule
Explanation - Renal pyramids are cone-shaped structures found in the medulla of the kidney.
Correct answer is: Medulla
Q.14 Which vessel carries filtered blood away from the glomerulus?
Afferent arteriole
Efferent arteriole
Renal vein
Peritubular capillary
Explanation - Blood exits the glomerulus via the efferent arteriole.
Correct answer is: Efferent arteriole
Q.15 Which muscle controls urination?
Detrusor muscle
Psoas major
Diaphragm
Rectus abdominis
Explanation - The detrusor muscle contracts to empty the bladder during urination.
Correct answer is: Detrusor muscle
Q.16 Which vein drains blood from the kidney?
Renal vein
Hepatic vein
Inferior mesenteric vein
Portal vein
Explanation - The renal veins drain blood from the kidneys into the inferior vena cava.
Correct answer is: Renal vein
Q.17 What structure prevents backflow of urine from the bladder to the ureters?
Sphincter muscle
Valves at ureter-bladder junction
Detrusor muscle
Pelvic diaphragm
Explanation - These one-way valves prevent urine from flowing backward into the ureters.
Correct answer is: Valves at ureter-bladder junction
Q.18 Which hormone stimulates sodium reabsorption in the kidneys?
Cortisol
Aldosterone
ADH
Thyroxine
Explanation - Aldosterone increases sodium reabsorption in the distal tubule and collecting duct.
Correct answer is: Aldosterone
Q.19 Which part of the nephron is responsible for countercurrent multiplication?
Proximal tubule
Loop of Henle
Distal tubule
Collecting duct
Explanation - The loop of Henle creates a concentration gradient essential for water reabsorption.
Correct answer is: Loop of Henle
Q.20 The hilum of the kidney allows passage of which structures?
Only renal artery
Only ureter
Renal artery, vein, and ureter
Only renal vein
Explanation - The hilum is the entry and exit site for vessels and ureter of the kidney.
Correct answer is: Renal artery, vein, and ureter
Q.21 Which waste product is primarily excreted by the kidneys?
Carbon dioxide
Urea
Bile salts
Lactic acid
Explanation - Urea is the main nitrogenous waste excreted in urine.
Correct answer is: Urea
Q.22 Which sphincter provides voluntary control over urination?
Internal urethral sphincter
External urethral sphincter
Detrusor muscle
Renal sphincter
Explanation - The external urethral sphincter is under voluntary skeletal muscle control.
Correct answer is: External urethral sphincter
Q.23 What is the average length of the adult urethra in males?
2 cm
4 cm
20 cm
10 cm
Explanation - The male urethra is approximately 20 cm long, while the female urethra is shorter (4 cm).
Correct answer is: 20 cm
Q.24 Which region of the kidney contains the renal corpuscles?
Medulla
Cortex
Pelvis
Papilla
Explanation - Renal corpuscles (glomerulus + Bowman's capsule) are located in the cortex.
Correct answer is: Cortex
Q.25 What structure connects the renal pelvis to the urinary bladder?
Ureter
Urethra
Collecting duct
Renal artery
Explanation - The ureter carries urine from the renal pelvis to the bladder.
Correct answer is: Ureter