This is a group of organs whose functions are co-ordinated and synchronized to perform the same function.
Organ systems are more pronounced in animals than in plants
Organ systems in animals include:
a) Digestive system composed of organs such as oesophagus, stomach, intestines and their associated glands.
b) Circulatory system composed of the heart, blood vessels (arteries, veins, capillaries).
c) Excretory system composed of kidney, liver,lungs and skin.
d) Respiratory system composed of trachea, bronchus, and lungs.
e) Reproductive system composed of the reproductive organs and associated glands.
f) Nervous systems composed of the brain, spinal cord, eye, ear organs.
Different organ systems form an organism.