Respiratory System

The Respiratory System is a distinct and important system that involves organs and structures for the movement and exchange of gases to allow an organism the capability of Respiration.

In Humans – the main gases involved include: Oxygen and Carbon Dioxide (CO2 ) and takes place in Lungs.

Inhalation is the process of bringing in fresh oxygen while exhalation is pushing out carbon dioxide and is referred to as breathing.

The gas exchange between “fresh” oxygen and “used” carbon dioxide is an essential aspect of human survival.

The exchange of gases occurs at the level of alveolars. Gas exchange occurs at the alveoli, which are tiny sacs that are the basic functional level of the lungs. Small capillaries are found close to these sacs and gas exchange occurs at this level

In most mammals that following are essential:

–  Lungs
–  Airways
–  Respiratory muscles
–  Oral cavity
–  Trachea
–  Bronchi
–  Diaphram

There are two categories of the respiratory tract

1.)  Upper Respiratory Tract
2.)  Lower Respiratory Tract

Upper Respiratory Tract includes:

–  Nasal passages
–  Pharynx
–  Larynx

Lower Respiratory Tract includes:

–  Trachea
–  Bronchi
–  Lungs


–  The respiratory system is less then required during pregnancy for the fetus.
–  At birth, this system becomes fully functional with the introduction of air.
–  There continues to be development throughout childhood.

Pre-term Delivery

–  Can cause several difficulties in the respiratory system of the newborn.
–  Important molecules such as surfactant may be limited or lacking at this time.
–  This may cause a decreased ability for oxygen and carbon dioxide exchange.


–  Ventilation occurs as a process with the autonomic nervous system
–  This occurs from the medulla oblongata and pons in the brain-stem
–  Areas within the brain form the respiration regulatory center – a connection of brain cells
–  4 sections include:  Pneumotaxic center, Apneustic Center, Dorsal Respiratory Group, and Ventral Respiratory Group.
–  Breathing rate increases as the concentration of carbon dioxide in the blood increases.
–  This is detected by chemoreceptors in Aorta and Carotid artery


–  The body’s need for balance is predicated upon by gas exchange in the lungs.
–  Carbon Dioxide is a waste product that can be very detrimental to maintaining balance.
–  The acid-base of the body can be jeopardized if proper ventilation is not maintained.
–  As a result – Respiratory Acidosis and Respiratory Alkalosis may occur.

1.)  Respiratory Acidosis is a decrease in the pH of the blood due to elevating carbon dioxide levels in the arteries.

2.)  Respiratory Alkalosis is a decrease amount of carbon dioxide level in the arteries.

*****Speech or rather the ability to vocalize is impart due to air passing the larynx and pharynx.