The Respiratory System

The Respiratory System

• The system that provides oxygen for the body and allows carbon dioxide to leave the body

• This system works in close association with the circulatory system

Label the diagram:Nasal cavity

Mouth

Trachea

Bronchi

Bronchiole

Lung

Ciliated epithelial cells

Alveoli

Structure of the Respiratory System

• Air enters through mouth and nasal cavity• Travels through trachea

• Trachea separates into to bronchi (singular – bronchus)• Bronchi split into bronchioles• Alveoli are small sacs at the ends of the bronchioles

• These are the sites of gas exchange with the circulatory system

Structure of the Respiratory System

• Many of the epithelial cells that line the respiratory pathway are goblet cells (produce mucus). In addition, these cells also contain cilia• Cilia help move mucus and filter out and materials that

may enter the system (bacteria, dust, etc.)

• The trachea is supported by rings of cartilage• This keeps the trachea open at all times,

while still allowing flexibility• (your ears are also made of cartilage)

Why doesn’t food get in my trachea?

• Because of the EPIGLOTTIS

• When you swallow, the epiglottis (a small flap) covers the opening of the trachea

Gas Exchange

• Oxygen and carbon dioxide need to be exchanged.

• This occurs between the alveoli of the respiratory system and the capillaries of the circulatory system• An alveolus is a sac of air at the end of

the respiratory system

• Each alveolus is surrounded by a capillary network

Gas Exchange• Blood coming from the heart is

deoxygenated (carrying CO2)

• The CO2 diffuses from the capillary to the alveolus

• O2 diffuses from the alveolus to the capillary

• The CO2 is EXHALED as waste

• The O2 is then brought back to the heart, where it is pumped to all cells in the body.

Disorders and Diseases

• Tuberculosis • Bronchitis• Bronchial Asthma• Carbon Monoxide Poisoning• Lung Cancer• Common Cold