Respiration in Organisms Class 7 Science - Breathing and Breathing Rate
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By watching this video, you will get an answer of How Respiration Takes Place in Human Body? What is Breathing and Breathing Rate?
Oxygen is needed for various body activities like energy production in cell. We obtain oxygen from the air around us with the help of nose and lungs.
The process of taking oxygen rich air inside the body is called inhalation.
The process of throwing air rich in carbon dioxide outside the body is called exhalation.
Together, inhalation and exhalation is called breathing.
Mechanism of Breathing: Air enters in the body through openings of the nose called nostrils. It flow through nasal cavity, enters in windpipe and then get filled in the lungs. This is inhalation. During inhalation, the muscular sheet called diaphragm situated below lungs undergo contraction. With this movement the pressure of air outside the body becomes larger than the pressure of air present in the lungs. After absorption of oxygen from air into blood, and release of carbon dioxide from blood into the lungs; the exhalation begins. To equalise the pressure, the excess air get rushed out of the body through nostrils. This is called exhalation.
Breathing Rate: A Breath is one inhalation and one exhalation. The number of times a person breathe during a minute is called his breathing rate. The breathing rate depends on need of oxygen. Which in turn depend on need of energy. On an average a normal human body is breathing at a rate of 12 - 18 breaths per minute.
