Human Anatomy & Physiology of the Respiratory System

Written by kim m. kesmetis
  • Share
  • Tweet
  • Share
  • Pin
  • Email
Human Anatomy & Physiology of the Respiratory System
(Google Images)

We often complete the daily tasks of living without thinking about the respiratory system. We breathe in and out and take for granted one of our most vital organ systems. The respiratory system provides the oxygen necessary to sustain life. It consists of both upper and lower respiratory tracts. It is divided into two functions: conducting and respiration.


The function of the respiratory system is to give us a surface area for exchanging gases between the air and our circulating blood. It moves that air to and from the surfaces of the lungs while it protects the lungs from dehydration, temperature changes and unwelcome pathogens. It also plays a part in making sounds such as talking, singing, other nonverbal sounds and works with the central nervous system for the ability to smell.

Upper Respiratory Anatomy

The upper respiratory system consists of the nostrils (external nares), nasal cavity, nasal vestibule, nasal septum, both hard and soft palate, nasopharynx, pharynx, larynx and trachea. Within the nostrils, course hairs protect us from dust, insects and sand. The hard palate serves to separate the oral and nasal cavities. There is a protective mucous membrane that lines the naval cavities and other parts of the respiratory tract. It is secreted over the exposed surfaces and then the cilia sweeps that mucus and any microorganisms or debris to the pharynx, so it is swallowed and then destroyed in stomach acids.

Lower Respiratory Anatomy

The trachea branches off into what is known as the bronchi (more commonly called bronchial tubes). These two main bronchi have branches forming the bronchial tree. Where it enters the lung, there is then secondary bronchi. In each lung, the secondary bronchi divides into tertiary bronchi and in turn these divide repeatedly into smaller bronchioles. The bronchioles control the ratio of resistance to airflow and distribution of air in our lungs. The bronchioles open into the alveolar ducts. Alveolar sacs are at the end of the ducts. These sacs are chambers that are connected to several individual alveoli, which makes up the exchange surface of the lungs.

The Lungs

The human respiratory system has two lungs, which contain lobes separated by deep fissures. Surprisingly, the right lung has three lobes while the left one has only two lobes. The lungs are made up of elastic fibres that gives it the ability to handle large changes in air volume. The pleural cavity is where the lungs are located. The diaphragm is the muscle that makes up the floor of the thoracic cavity and plays a major role in the pressure and volume of air moving in and out of the lungs.


Our lungs filter and deliver oxygen that is necessary for healthy red blood cells. It is important that we keep the respiratory tract healthy through proper rest, hydration, diet and exercise.

Don't Miss

  • All types
  • Articles
  • Slideshows
  • Videos
  • Most relevant
  • Most popular
  • Most recent

No articles available

No slideshows available

No videos available

By using the site, you consent to the use of cookies. For more information, please see our Cookie policy.