Respiration notes

credit to www.ssijbsainspmr.blogspot.com/yschow@smkbpj(a)

SCIENCE FORM 3

Unit 1
Respiration

Human Breathing Mechanism

                             





    Human Respiratory System
1. Living organisms must be able to take oxygen from the air and get rid of carbon dioxide to the air.
2. Gas exchange takes place through a gas exchange surface, also known as a respiratory surface.
3. Breathing is also known as external respiration.
4. Breathing consists of two stages:
                   a. Inhalation - during which air is taken into the lungs.
                   b. Exhalation - during which air passes out of the lungs.
5. The breathing system or the human respiratory system consists of the following structures or organs:
                   a. The nasal cavity                                     
                   b. Trachea
                   c. Bronchus (plural: bronchi)
                   d. Bronchiole
                   e. Lungs
                   f. Alveolus (plural: alveoli)
                   g. Rib cage
                   h. Diaphragm
                   i. The intercostal muscles
                   j. Internal intercostal muscles,
                   k. External intercostal muscles.







6. Flow of air into the lungs
                       a. Air is breathed in through the nose and enters the nostrils.
                       b. The nostril leads to the nasal cavity where the air is warmed up and moistened.
                            i. Hairs and sticky mucus trap particles inside the nasal cavity.     
                       c. The air then enters the trachea.