RESPIRATION ~form 3~

  # RESPIRATION  = living process in which energy is released from the food we eat.

THE STRUcTURE OF THE HUMAN RESPIRATORY SYSTEM.

@ nostrils.~the walls of the nostrils are lined with hairs to trap dust particles in the air. 

@nasal cavity. ~the interior are of the nose.

@bronchi. ~2 main air passages into the lungs .each bronchus branches into smaller tubes called bronchioles

THE PASSAGE OF AIR

nostrils -> nasal cavity -> trachea -> bronchus -> bronchiole -> alveolus

INHALATION = breath in air

EXHALATION = breath out air

INHALATION 

• intercostal muscles contracts
• rib cage moves outwards
• diaphragm contracts and flatten
• volume of thoracic cavity increases
• air pressure in thoracic cavity decrease

EXHALATION

• intercostal muscles relaxes
• rib cage moves inwards
• diaphragm relaxes and curves upwards
• volume of thoracic cavity decreases
• air  pressure in thoracic cavity increase

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