Student Nurse's Guide to Respiration

Respiration is the process in which oxygen is obtained from the outside environment of the body and delivered to the cells inside the body. There are three phases of respiration: Pulmonary ventilation, diffusion and transportation.

External respiration is the exchange of oxygen that goes into the lungs and when carbon dioxide leaves the lungs while internal respiration is where oxygen and carbon dioxide is exchanged on the cellular level.

Our bodies know how to breathe due to carbon dioxide accumulates in the blood which makes the blood acidic. This then triggers our body to exhale to "blow off" the carbon dioxide and to inhale to bring our blood back to alkaline. Normal respiration rates for an adult are 14 to 20 breaths per minute, children 20 to 24 breaths per minute and for infants 40 to 60 breaths per minute.

The upper respiratory tract consists of the nose, pharynx, larynx and trachea and the lower respiratory tract consists of the bronchial tree which is made up of the bronchioles, alveolar ducts and the alveoli.

When air enters our bodies it initially takes place through the nasal cavities, which are made up of hyaline cartilage. The nasal cavities are covered in mucus membranes that help deliver heat and moisture. The hairs in the nostrils help to remove and filter any foreign bodies that may try to enter in through the nasal cavities.

Our sinuses are the small cavities in the bones of the skull that are lined with mucus membranes these areas are highly susceptible to infections.

Pharynx (throat) carries air to the respiratory areas and food to the digestive areas. The pharynx is actually made up of three parts; the nasopharynx which is located behind the nose, the oropharynx which is located in the by the mouth and then laryngeal pharynx which is located near the larynx.

The larynx (voice box) is located between the pharynx and the trachea it is the framework that is made up of cartilage and houses the Adam's apple on men. The folds on either side of the larynx are what are known as the vocal cords, these cords produce speech. It is the air that causes the vibrations to allow for speech. The space between the vocal cords is called the glottis, and the leaf shaped cartilage that covers the larynx during swallowing is called the epiglottis, the epiglottis prevents aspiration from happening.

The trachea (windpipe) is the tube that extends from the larynx to the upper part of the chest. The tracheas purpose is to conduct air between the larynx and the lungs, the inferior end of the trachea divides into the right and left bronchi.