Respiratory System

The respiratory system.The body needs oxygen in the blood stream to feed the cells for respiration.It also needs to get rid of C02 from the blood.This all happens in the lungs when you breathe in and out.

ThoraxThe thorax is the top part of your body, and is separated from the bottom half by the diaphragm.Inside are the big pink sponges called the lungs, surrounded by pleural membranes and are protected by the rib cage.

Air breathed in travels through the trachea, this splits into two tubes called bronchi (bronchus) one to each lung.The bonchi split further into smaller tubes called bronchioles.Bronchioles finally end at small bags called alveoli, where gas exchange takes place.

Breathing In....Intercostal muscle and diaphragm contract.The thorax volume increase.This decreases the pressure, drawing in air.

Breathing out....Intercostal muscles and diaphragm relax.Thorax volume decreases.Air is forced out.

Exercise on breathing...To show the effect of exercise on breathing.  Stay still for a while, after a period of time count the number of breaths you take in 1 minute.Then perform 4 minutes of exercise, once you stop count the number of breaths.To make the experiment valid try to get two others to do the same so the results can be compared.You should find that after exercise you breath more than when you are at rest.This is due to exercise increasing the breathing rate, this happens because muscles respire more during exercise, therefore they require more 02  and have to remove more C02.  So breathing rate increases.experimental controls can be the time spent exercising, and the temperature of the room.

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