Excretory Products and their Elimination

Excretory System In Humans (Group B)

 

Excretion

• Removal of nitrogenous wastes from the body

Nitrogenous wastes

• Ammonia

  • Most toxic

  • Needs more water for getting excreted

  • Diffuses across general body surfaces

  • Examples of organisms excreting ammonia: fishes, aquatic amphibians and aquatic insects

  • Such organisms are called ammonotelic.

• Urea

  • Less toxic

  • Requires less water for excretion

  • Terrestrial adaptation for conservation of water

  • Ammonia Urea

  • Examples of organisms excreting urea: terrestrial amphibians and marine fishes

  • Such organisms are called ureotelic.

• Uric acid

  • Least toxic

  • Eliminated with the least loss of water, as pellets or paste

  • Examples of organisms excreting uric acid: birds, reptiles, land snails and insects

  • Such organisms are called uricotelic.

Human excretory system

It comprises of: 

i. pair of kidneys

ii. pair of ureters

iii. urinary bladder

iv. urethra

• Kidney is divided into outer cortex and inner medullary region.

• Nephrons are basic functional units of kidney.

 

 

 

Excretion

• Removal of nitrogenous wastes from the body

Nitrogenous wastes

• Ammonia

  • Most toxic

  • Needs more water for getting excreted

  • Diffuses across general body surfaces

  • Examples of organisms excreting ammonia: fishes, aquatic amphibians and aquatic insects

  • Such organisms are called ammonotelic.

• Urea

  • Less toxic

  • Requires less water for excretion

  • Terrestrial adaptation for conservation of water

  • Ammonia Urea

  • Examples of organisms excreting urea: terrestrial amphibians and marine fishes

  • Such organisms are called ureotelic.

• Uric acid

  • Least toxic

  • Eliminated with the least loss of water, as pellets or paste

  • Examples of organisms excreting uric acid: birds, reptiles, land snails and insects

  • Such organisms are called uricotelic.

Human excretory system

It comprises of: 

i. pair of kidneys

ii. pair of ureters

iii. urinary bladder

iv. urethra

• Kidney is divided into outer cortex and inner medulla…