Q11. What is the process by which waste products, toxins, and excess substances are removed from the bloodstream and expelled from the body?
a) Filtration
b) Absorption
c) Excretion
d) Secretion
Show Answer
Correct Answer: c) Excretion
Explanation: Excretion is the process by which waste products, toxins, and excess substances are removed from the bloodstream and expelled from the body. It involves filtration of blood in the kidneys, reabsorption of essential substances, and secretion of waste products to form urine.
Q12. Which of the following is NOT a function of the kidneys?
a) Regulation of blood pressure
b) Regulation of blood glucose levels
c) Regulation of blood pH
d) Production of urine
Show Answer
Correct Answer: b) Regulation of blood glucose levels
Explanation: While the kidneys play a role in glucose metabolism by reabsorbing glucose from the filtrate, their primary function is not the regulation of blood glucose levels. Instead, this function primarily falls under the purview of the endocrine system, particularly the pancreas and insulin.
Q13. What is the term for the process of removing metabolic waste products, such as urea and uric acid, from the bloodstream through the formation of urine?
a) Glomerular filtration
b) Tubular reabsorption
c) Tubular secretion
d) Urinary excretion
Show Answer
Correct Answer: d) Urinary excretion
Explanation: Urinary excretion is the process of removing metabolic waste products, such as urea and uric acid, from the bloodstream through the formation of urine in the kidneys. It involves filtration, reabsorption, and secretion processes within the nephrons.
Q14. Which of the following substances is NOT normally found in urine under healthy physiological conditions?
a) Urea
b) Glucose
c) Creatinine
d) Sodium ions
Show Answer
Correct Answer: b) Glucose
Explanation: Glucose is not normally found in urine under healthy physiological conditions. Its presence in urine (glycosuria) may indicate underlying health issues such as uncontrolled diabetes mellitus, where the kidneys cannot reabsorb all the filtered glucose back into the bloodstream.
Q15. Which of the following structures carries urine from the bladder to the outside of the body during urination?
a) Urethra
b) Ureter
c) Renal pelvis
d) Nephron
Show Answer
Correct Answer: a) Urethra
Explanation: The urethra is the tubular structure that carries urine from the bladder to the outside of the body during urination. In males, it also serves as the passage for semen during ejaculation. The length of the urethra varies between males and females.
Q16. What is the name of the process by which water and solutes are selectively reabsorbed from the renal tubules back into the bloodstream?
a) Glomerular filtration
b) Tubular reabsorption
c) Tubular secretion
d) Urine formation
Show Answer
Correct Answer: b) Tubular reabsorption
Explanation: Tubular reabsorption is the process by which water and solutes, such as glucose, amino acids, and ions, are selectively reabsorbed from the renal tubules back into the bloodstream. This process helps maintain the body’s water and electrolyte balance.
Q17. Which hormone regulates the reabsorption of water in the kidney tubules, thereby influencing urine concentration?
a) Aldosterone
b) Antidiuretic hormone (ADH)
c) Renin
d) Atrial natriuretic peptide (ANP)
Show Answer
Correct Answer: b) Antidiuretic hormone (ADH)
Explanation: Antidiuretic hormone (ADH), also known as vasopressin, regulates water reabsorption in the kidney tubules by increasing the permeability of the collecting ducts to water. This hormone helps the body conserve water and maintain proper fluid balance by influencing urine concentration.
Q18. Which of the following is a function of the renal medulla?
a) Filtration of blood
b) Reabsorption of glucose
c) Formation of urine
d) Maintenance of blood pH
Show Answer
Correct Answer: c) Formation of urine
Explanation: The renal medulla is responsible for establishing and maintaining the osmotic gradient necessary for the formation of concentrated urine. This region of the kidney contains structures such as the Loop of Henle and collecting ducts, which play crucial roles in urine concentration.
Q19. Which of the following is NOT a component of the renal corpuscle?
a) Glomerulus
b) Bowman’s capsule
c) Renal tubule
d) Podocytes
Show Answer
Correct Answer: c) Renal tubule
Explanation: The renal corpuscle consists of two main structures: the glomerulus, a network of capillaries where blood filtration occurs, and Bowman’s capsule, a double-walled epithelial cup that surrounds the glomerulus and collects the filtrate. The renal tubule is part of the nephron located downstream from the renal corpuscle.
Q20. Which segment of the nephron is primarily responsible for the reabsorption of water, sodium ions, and other solutes from the filtrate?
a) Glomerulus
b) Bowman’s capsule
c) Proximal convoluted tubule
d) Distal convoluted tubule
Show Answer
Correct Answer: c) Proximal convoluted tubule
Explanation: The proximal convoluted tubule (PCT) is the segment of the nephron responsible for the reabsorption of water, sodium ions, glucose, amino acids, and other essential solutes from the glomerular filtrate back into the bloodstream. It plays a crucial role in maintaining the body’s water and electrolyte balance.