Introduction:
Respiration is the physiological process involving movement of oxygen from the outside environment into the cell within tissues and transportation of carbon dioxide in the opposite direction.
The respiratory center is made up of three major respiratory groups of neurons, two in the medulla and one in the pons.
The respiratory center is responsible for generating and maintaining the rhythm of respiration.
Like other systems of the body Respiratory system also works in coordination with other systems.
The branch of science that deals with the structure, function, diagnosis and treatment of diseases of lungs is called Pulmonology.
The study of Nose and Pharynx and Larynx is covered in ENT (Ear Nose Throat).
Respiratory System consists of,
Nose (Nasal Cavity).
Pharynx.
Larynx.
Trachea.
Lungs.
Mechanism of Breathing:
The process of moving air in and out of the lungs is called “Breathing”.
Breathing, or pulmonary ventilation, consists of two phases: inspiration, the period when air flows into the lungs, and expiration, the period when gases exit the lungs.
The major mechanisms that cause breathing are,
Atmospheric pressure,
Intrapulmonary Pressure,
Intrapleural Pressure.
The muscles that play major role in breathing are,
Intercostal muscles.
Diaphragm.
Inspiration:
The phase of breathing when atmospheric air enters lungs is called inspiration.
Mechanism of inspiration involves following steps,
Intercostal muscles contract.
The ribs are pulled upward.
Diaphragm contracts and moves downwards.
It results in increased “Lung Volume.”
As lung volume increases intrapulmonary pressure decreases in comparison to atmospheric pressure.
The atmospheric air moves from high pressure to low pressure i.e. in lungs.
The inspiration is followed by expiration.
Expiration:
The phase of breathing in which the gases move out from lungs into the atmosphere is called expiration.
Mechanism of expiration involves following steps,
Intercostal muscles relax.
The ribs come back to normal.
Diaphragm relaxes and again forms its dome shape.
It results in decreased “Lung Volume.”
As lung volume decreases intrapulmonary pressure increases in comparison to atmospheric pressure.
The atmospheric air moves from high pressure to low pressure i.e. outside the lungs.
The expiration is followed by inspiration.
Commonly Asked Questions.
Draw a well labelled diagram of the Respiratory System.
Write a short note on the mechanism of breathing.