The Circulatory and Respiratory System: Parts, Functions, and Importance

Week 2: The Respiratory System

● The systemʼs main function is to transport oxygen to the body cells and to
get rid of carbon dioxide.

● Respiration is a complex process through which oxygen is obtained from the
environment and then delivered to the blood cells, and through which carbon
dioxide is collected, transported, and disposed of to the environment.



Respiratory System
● Used for gas exchange


● Moving and taking in of oxygen, moving and taking out of carbon dioxide

● Inhaling (oxygen), exhaling (carbon dioxide)

● Is a mechanical process; can be controlled voluntarily



Conduction Zones
● Upper respiratory tract


○ Nasal cavity

○ Pharynx

○ Larynx

● Lower respiratory tract

○ Trachea

○ Lungs

◆ Bronchi

◆ Bronchioles

◆ Alveoli

, Respiration involves three main events:
H. Breathing – inhalation and exhalation; the process of exchanging air between
the atmosphere and the lungs


I. Diffusion – the transfer of oxygen and carbon dioxide across respiratory
membranes (oxygen is taken from the lungs while carbon dioxide is released
from the blood)


J. Transport of gases – oxygen is carried into the cells and carbon dioxide is
delivered to the lungs and out of the body