The respiratory system
The respiratory system is responsible for providing oxygen and removing carbon dioxide, heat and water vapours. All living creatures require oxygen and give off carbon dioxide. Oxygen is required for every cell in your body to function. Structure of the respiratory system:
Normally air is taken in through your nose however sometimes it is taken in through your mouth and passes through a series of airways to reach the lungs. This series of airways is known as the respiratory tract and can be divided into two parts. The upper respiratory tract includes the nose, nasal cavity, mouth, pharynx and larynx; and the lower respiratory tract includes the trachea, bronchi and lungs. Nasal cavity: Your nose is divided into the external nose and the internal nasal cavity. When you breathe in the air enters through the nostrils into the cavity. The hair in your nostrils filters the air to get rid of the stuff that’s not needed like dust before it passes into the two passages of the nasal cavity. The air is then warmed and moistened in the passages before it passes into the nasopharynx. A sticky mucous layer traps small objects that the hair in the nostrils didn’t filter out and is sent to the pharynx to be swallowed by the tiny hairs called cilia. Epiglottis: This is a small flap at the back of your tongue, the epiglottis closes the top of the trachea when you swallow to make sure food and drink go down to your stomach and not into your lungs. Pharynx: This connects the nasal cavity and mouth to the larynx and oesophagus. This is known as the throat, the pharynx is a small tube from the base of the skull to the sixth cervical vertebra. The muscular pharynx wall is made up of skeletal muscle throughout its length. This is a passageway for food as well as air; therefore special adaptations are required to prevent chocking from happening. Larynx: This known as the voice box. The larynx has rigid walls of muscle and cartilage, it contains the vocal...
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