The animals which live in water ( aquatic animals) use the oxygen dissolved in water to carry out respiration . Since the amount of dissolved oxygen in water is low as compared to the amount of oxygen in the air, therefore, the rate of breathing in aquatic animals is much faster than in terrestrial animals. A faster rate of breathing provides more oxygen to aquatic animals.
Pathway of air in human beings `:`
Nostrials `rarr` Pharynx` rarr` Larynx ` rarr` Trachea ` rarr ` Lungs
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(i) A group of endocrine glands which produces various hormones is called an endocrine system. The endocrine system is also called hormonal system.
(ii) The endocrine system also helps in coordinating the activities of our body . The endocrine system in our body consists of a number of glands ( or tissues ) which make, store, and release chemicals called hormones.
(iii) The working of endocrine glands is controlled by our nervous system. The hormones produced by endocrine glands act as messengers between the nervous system and the organs of our body.
