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Renin Angiotensin Mechanism.

Introduction to Respiratory System.

 

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.

  1. Draw a well labelled diagram of the Respiratory System.

  2. Write a short note on the mechanism of breathing.
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