Chapter Eight

• Knowledge-based Questions:

Question 1: What is excretion?

Answer:  Excretion is a biological process of the human body in which the waste materials produced by metabolic activities are removed from the body.

Question 2: What is renal capsule?

Answer:  Kidneys are enclosed with a special fibrous membrane, called the renal capsule.

Question 3: What is hilum?

Answer: Hilum is the indentation seen inside the concave inner side of the kidney.

Question 4: What is papilla?

Answer:  The apex of each pyramid present in the medulla of the kidney is called papilla.

Question 5: What is glomerular filtrate?

Answer:  The glomerular filtrate contains urea, water, vitamins, fatty acids, water, glucose, nitrogen, salts, etc. The glomerular filtrate enters the nephrons for further filtration termed ultrafiltration.

Question 6: What is the function of glomerulus in kidney?

Answer: In kidney, glomerulus acts as a filter and produces filtrate from blood.

Question 7: What is ultrafiltrate?

Answer: The liquid filtrate formed in the glomerulus from blood in Bowman’s capsule is called ultrafiltrate.

Question 8: What is pelvis?

Answer: The funnel-shaped extended part of the ureter is called the renal pelvis.

Question 9: What is medulla?

Answer:  The inner part inside the renal capsule is called medulla.

Question 10: What is renal tubule?

Answer:  The convoluted tubules placed behind Bowman’s capsule are called renal tubules.

Question 11: What is glomerulus?

Answer:  Glomerulus is a small cluster of blood vessels formed by afferent arterioles placed inside Bowman’s capsule.

Question 12: What is renal corpuscle?

Answer: Renal corpuscle is formed of Bowman’s capsule and glomerulus placed in front of nephrons.

Question 13: What is nephron?

Answer: Nephron is the functional unit of the kidney.

Question 14: What is osmoregulation?

Answer: Osmoregulation is the process of removing excessive water from the body that is stored in blood to maintain body water balance.

Question 15: What is dialysis?

Answer: When the human kidneys are badly damaged or inactive then the blood can be purified by a method is called dialysis.

Question 16: What is ‘brain dead’?

Answer: ‘Brain dead’ refers to the death of a person where they will never gain consciousness again but their organs are kept active by using an external machine.

• Comprehension-based Questions:

Question 1. Why kidney is called the filter of human body?

Answer: Each kidney contains about one million tiny units called nephrons. Each nephron is made up of a very small filter, called a glomerulus, which is attached to a tubule. As blood passes through the nephron, fluid and waste products are filtered out. That is why kidney is called filter of the body.

Question 2.What is meant by kidney stone? Explain.

Answer: The formation of small sized stones in the kidney is known as kidney stones. Excess body weight, kidney infections, drinking inadequate water and excess protein intake causes kidney stones. Back pain occurs from kidney stones.

Question 3. Eplain the causes why stone is produced in kidney.

Answer: Small stone like substances produced by the kidneys are called kidney stones. Male suffers from this disease than females. The other causes of kidney stone formation are- obesity, infection in the kidneys, drinking insufficient water etc.

Question 4. Why Hilus is called a junction?

Answer: The concave surface of the kidney having an indentation is called Hilus. The hilus is the concave part of the bean-shape where blood vessels and nerves enter and exit the kidney; it is also the point of exit for the ureters. That is why hilus of kidney is called a junction.

Question 5. What do you mean by dialysis?

Answer: When the kidneys are badly damaged or inactive then the blood can be filtered or purified by a scientific method called dialysis. Generally, dialysis is done by a dialysis machine. One end of the dialysis tube of the machine is led to the artery of the patient’s wrist and is led to the vein of the same wrist.

Question 6. What do you mean by kidney transplant?

Answer: Transplantation of kidney can be done by taking it from a close relative or a dead person posthumousy. When the kidneys become damaged or inactive, they can be replaced by a healthy kidney of a healthy person. This is called kidney transplantation.

Question 7. What do you mean by osmoregulation?

Answer: Osmoregulation is the process by which an organism regulates the water and electrolytic balance in its body to maintain homeostasis. It maintains the internal environment of the body by water and ionic concentration. It also regulates the optimum temperature of water and salts in the tissues and body fluids.

Or

Osmoregulation is the active regulation of the osmotic pressure of an organism’s body fluids. Water balance is maintained in the human body through osmoregulation. For all physiological processes, an adequate amount of water is necessary. Excessive water is removed from the body as urine. The main function of the kidney is to keep the balance of water. The Nephrons of the kidney maintain water equilibrium through reabsorption. Excretory fluids, water and other substances are filtered in the glomerulus. In failure of the kidneys, water accumulates in the body.

Question 8. Why is special type of fluid used in dialysis machine? Explain.

Answer: When kidney failure happens then the process of purifying by scientific method is named dialysis. A kidney/dialysis machine receives blood through a tube connected to an artery. The dialysis tubing is bathed in a liquid similar to blood plasma in such a way that the kidney machine purifies blood through dialysis tubing.

This allows wastes to diffuse out of the blood. Since, the kidney cannot complete the process of purification by itself, the blood plasma is used in dialysis machines.

Question 9. Why is urine acidic or alkaline.

Answer: The color of the urine is light yellow due to the presence of a pigment called urochrome. Excessive intake of proteins increases the acidity of urine. Fruits and vegetables generally make urine alkaline.