Download Respiratory System Notes

The Respiratory System
9 Biology
Importance of Respiratory System
• Sustains cellular respiration by supplying
oxygen and removing carbon dioxide.
• Two Components:
– 1. Breathing- mechanical movement of air into
and out of the lungs
– 2. Gas exchange
• External: exchange of gases between atmosphere and
blood
• Internal: exchange of gases between blood and body
cells
Anatomy of Respiratory System
Structures:
• Nose pharynx larynx trachea
• Bronchus bronchioles alveoli
– Capillary beds in alveoli are where gases are
exchanged.
Alveoli
• Thin walled cells
surrounded by thin
capillaries
– O2 diffuses in, CO2
diffuses out
– CO2in blood exists as
carbonic acid dissolved
in plasma, bound to
hemoglobin
Mechanics of Breathing:
• Inhalation- diaphragm goes down to allow
filling of lungs
• Exhalation- diaphragm goes up to push air out
of lungs
• Intercostal muscles (between ribs) assist with
process
Respiratory Disorders
• Asthma- airways swell, restricting air flow
• Bronchitis- airways become infected
• Emphysema- alveoli break down, reducing surface area
for gas exchange
• Pneumonia-infection of lungs that causes mucous to
collect in alveoli
• Pulmonary tuberculosis- bacterial infection that
reduces capillary absorption
• Lung cancer- uncontrolled cell growth in lungs that
causes coughing, shortness of breath, pneumonia,
infection and death.
Respiratory Disorders