The Respiratory system
Parts Divided into 2: Respiratory Tract The Lungs Nasal cavity Pharynx Trachea Bronchi The Lungs Alveoli
Role of System Gaseous exchange between surrounding air and blood Oxygen diffuses from alveoli to blood Carbon dioxide diffuse out from blood to alveoli
Function of Nasal Cavity Filters air with hairs Warm and moisten air with mucus
Function of Lungs Where gas exchange occurs between the body and the outside world
Mechanics of Respiration 2 important structures Intercostal muscles (muscles located between the ribs) Diaphragm (muscle that seperates rib cage from abdomen)
Inhalation Air rich in O₂ and poor in CO₂ Intercostal muscles and diaphragm contract Ribs rise Diaphragm descends Rib cage ↑ in size Lung volume ↑ Air pressure ↓ O₂ rich air from outside flows into lungs until pressure inside and outside of lungs is equal
Exhalation Air rich in CO₂ and poor in O₂ Intercostal muscles and diaphragm relax Ribs descend Diaphragm rises Size of rib cage ↓ Lung volume ↓ Air pressure ↑ CO₂ rich air inside lungs flows outside until pressure inside and outside lungs is equal
Gas exchange within the lungs The O₂ that has been absorbed by the lungs must reach all the cells of our body! This is why our blood needs to be circulated The same goes for the waste product produced (CO₂) needs to be carried by the blood to be expelled from the body This exchange of gases occurs in the ALVEOLI
Gas exchange within the lungs Alveoli→ miniature sacs that fill with air and make up the bulk of the lungs Each alveoli is surrounded by blood vessels called capillaries When the blood reaches the alveoli, it is CO₂ rich The air in the alveoli is O₂
Gas exchange