The Excretory system

Question 1

Define Excretion

Answer 1

It is process of removal of chemical wastes (mainly nitrogenous wastes) from the body is known as Excretion.

Question 2

What are the substances that are supposed be removed in excretion.

Answer 2

Carbon dioxide and water - eliminated through the lungs and water in form of sweat.
Nitrogenous wastes - consists of urea, uric acid and ammonia. Urea is excreted through kidneys.
Excess salts are given out by kidneys.

Question 3

Name organs present in the Excretory systems

Answer 3

Kidneys - primary excretory organ for removal of nitrogenous wastes
Skin - excretes in form of sweat
Lungs - excrete CO2
Liver - Detoxifies ammonia by converting it into urea excreted through urine.

Question 4

Explain the external structure of Kidneys.

Answer 4

• 2 bean shaped organs about 10 cm long and 6 cm wide located on the either side of the backbones.
• A tube, the ureter, arises from hilum.
• hilum is the notch in the median surface of each kidney
• The ureter connects with the urinary bladder in the lower part of abdomen.
• The front end of the ureter is somewhat expanded into the kidney is the pelvis.

Question 5

Explain the internal structure of kidneys

Answer 5

There are 2 main regions - the Cortex and the Medulla

• Medulla is composed of a finely striped substances arranged in several conical pyramids.
• The apex of each pyramid is called papilla which projects into the pelvis of the kidney.
• portions of the cortical tissue extend in between adjacent renal pyramid to form renal columns.
• The Kidney is composed of as enormous number of the minute tubules called uriniferous tubules or nephron or renal tubules or just kidneys tubules.

Question 6

Explain how Nephrons function.

Answer 6

It takes in impure blood from the renal artery and remove waste in from of urine. It also provides a longer surface area for reabsorption of salt and water.

Question 7

Define Ultrafiltration

Answer 7

The process of filtration of blood in the glomerulus under pressure during which the liquid part of the blood.

Question 8

Define Osmoregulation

Answer 8

It is a process of maintaining the blood composition of the body that is the normal osmotic concentration of water and salt.

Question 9

Define Micturition

Answer 9

The process of the expelling urine out of the body through urethra by opening sphincter muscles passing of urine relation between urinary bladder and urethra.

Question 10

What is dialysis

Answer 10

Dialysis involves the use of artificial kidney/dialysis machine. The patients blood is passed from the renal arteries. It is laid through machine where excess salt and urea is removed. The purified blood is then returned to the same arm.

Question 11

Give structure of Nephron

Answer 11

Nephrons are a long tube which is heavily supplied with blood. The blind end is as if as if double walled cup like structure called Bowman’s capsule. It has a group of capillaries called glomerulus. Glomerulus and Bowman’s capsule together are called Malpighian body/capsule.
Henle’s loop is (shaped like a hair pin) not convoluted. It runs in medulla to turn back and to re-enter the cortex to continue into the next convoluted region of the tubule.