Excretion in Humans Beings | Human Excretory System Parts and Functions

In this section, you will read about excretion in human beings. In addition, you will also get to solve various important MCQs on human excretory system.

Excretion in Animals | Human Excretory System

Excretion refers to sum total of all the processes of removing the waste products of cellular metabolism and extra water from the body.

The excretory system in humans consists of a pair of kidneys, a pair of ureters, a urinary bladder and a urethra. In addition, organs like liver, large intestine, lungs also act as excretory organs.

During excretion, Nitrogenous wastes such as urea and uric acid , and water are removed.

Nephron is the basic filtration unit. Main components of the nephron are :glomerulus, Bowman’s capsule, renal tube.


Kidneys are present on either side of the backbone in the abdomen.

Kidneys produce urine and urine from kidney passes through the ureters into the urinary bladder

Each Kidney is divided into three distinct regions:

structure of kidney

(a) Outermost cortex: consists of nephrons

(b) Middle Medulla region: consists of tubules

(c) Inner Pelvis region: where urine is drained from all the collecting tubules.

The functional unit of kidney is NEPHRON.

Each kidney consists of millions of nephrons and each nephron consists of the following parts:

Structure of Nephron

(a) Bowman’s capsule: It is a cup shaped structure and receives the blood vessels.

(b) Proximal Convoluted Tubule: Water and reusable materials from the blood are now reabsorbed back into it.

(c) The loop of Henle: It is in this area in which urine becomes concentrated as water is reabsorbed.

(d) Distal Convoluted Tubule: It is where the kidney hormones cause their effect.

(e) Collecting Duct: The collecting ducts together form the renal pelvis.


Water vapours and carbon dioxide are excreted from the human body through lungs.

Lungs are the primary respiratory organs.


The skin is the largest organ in the body.

Sweat glands filter water, urea and salts from the blood. Although the main role of sweat production is to cool the body and maintain temperature homeostasis, sweating also eliminates excess water and salts, as well as a small amount of urea

Skin protects the different organs of the body.


Liver removes worn out cells and excess of amino acids from the blood.  liver converts ammonia( a toxic by-product of protein catabolism) into urea, which is then filtered from the blood by the kidneys and excreted in urine.

It is the first line of defence when it comes to hormones, fats, alcohol, and drugs.

Large Intestine

The main function of large intestine as an excretory organ, is to eliminate solid wastes that remain after the digestion of food and the extraction of water from indigestible matter in food waste.

The disorders related to excretion in animals are discussed below:

AnuriaWhen no urine is passed
DysuriaPainful Urination
PolyuriaExcessive Urination
NocturiaUrination during night
UremiaIncreased level of urea in blood
Diabetes InsipidusExcessive urination due to defeciency of Antidiuretic hormone, mainly in alcoholics.
UrethritisInflammation of Urethra
Renal failureFailure of kidneys
Renal CalculiStones in kidneys

MCQs On Human Excretory System

This set contains many important MCQs on human excretory system. Solve these MCQs on to check and enhance your level of preparation for competitive exams.

What is the basic functional unit of Kidney?

  1. Nephron
  2. Glomerulus
  3. Loop of Henli
  4. Neuron


The largest excretory organ is:

  1. Lungs
  2. Skin
  3. Large intestine
  4. Kidney


Urea is produced as an excretory substance in human body in:

  1. Urinary Bladder
  2. Liver
  3. Kidney
  4. Large intestine


Bowman’s Capsule is also known as:

  1. Adrenal Capsule
  2. Renal Capsule
  3. Hepatic Capsule
  4. Gastric Capsule

Renal Capsule

The disorder in which large amounts of urine are produced is known as:

  1. Diabetes Millitus
  2. Dysuria
  3. Mycturia
  4. Diabetes Insipidus

Diabetes Insipidus

Females are more prone to Urinary Tract Infection because;

  1. They have longer urethra than men.
  2. They have shorter urethra than men.
  3. Their urinary bladder is rigid and small.
  4. Their ureters are shorter than men.

They have a shorter urethra than men

The disorder in which urea accumulation is comparatively higher is known as:

  1. Nephritis
  2. Renal Calculi
  3. Uremia
  4. Dysuria


The ph of human urine is normally:

  1. 3 to 5
  2. 4.6 to 8.0
  3. 7.2 to 10.4
  4. 7

4.6 to 8.0

The condition characterized by no passage of urine is known as:

  1. Dysuria
  2. Polyuria
  3. Nocturia
  4. Anuria


The main function of the large intestine is:

  1. Concentrating bile juice
  2. Absorbing nutrients from chyme
  3. making hormones that regulate blood sugar
  4. compacting and eliminating waste materials

compacting and eliminating waste materials

The sweat glands release waste products like:

  1. Water and bile
  2. Water and salts
  3. salts and bile
  4. Salts and bilirubin

Water and Salts

These were some important MCQs on human excretory system. We are sure that you will find these MCQs on human excretory system very useful and hope that you will share them with your friends.

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