RESPIRATORY SYSTEM

Function

The function of the respiratory system is gas exchange. It makes sure the body has a steady supply of oxygen while it disposes of carbon dioxide.

Respiratory Processes

Ventilation: exchange of gases between the outside and the lungs

  External respiration: exchange of gases between

the lungs and the blood   Internal respiration: exchange of gases between

the blood and the tissues   Cellular respiration: reaction of oxygen and

glucose to produce energy, water and carbon dioxide

1. nasal cavity2. nose3. mouth4. bronchi5. bronchiole6. alveolus7. diaphragm8. epiglottis9. trachea10. left lung11. ribs

Parts

Nasal Cavity: Space inside the nose Pharynx: Joint passage for air and

food Epiglottis: Flap of tissue that

prevents objects from entering trachea

Trachea: Semi-rigid tube lined with rings of cartilage

Parts

Larynx: the voice box Alveoli: Site of gas exchange

(external respiration) Diaphragm: Dome-shaped muscle

used in breathing

Ventilation

Ventilation is the exchange of gases between the outside and the lungs. During inhalation, the diaphragm (and intercostal muscles) contract. This increases the volume of the lungs. The pressure inside the lung drops and air moves into the lungs.

  During exhalation, the diaphragm relaxes.

This decreases the volume of the lungs. The air pressure inside the lungs increases and air moves out.

Diseases

Asthma: narrowing of the bronchi causes coughing wheezing and difficulty breathing

Tuberculosis: bacterial infection causing fever, sweats and spitting blood

Bronchitis: lung infection causing coughing, mucus production, narrowing of bronchi

Pneumonia: lung infection in which alveoli become filled. Cough and chest pain

Rhinitis: inflammation of the mucous membrane of the nose