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Anatomy of the Respiratory System

Respiration

Respiration is the act of breathing:

  • Inhaling. The act of breathing in oxygen.

  • Exhaling. The act of breathing out carbon dioxide.

Respiratory system

Illustration of the human respiratory system
Respiratory System - Click to Enlarge

The respiratory system is made up of the organs included in the exchange of oxygen and carbon dioxide. These are the parts:

  • Nose

  • Mouth

  • Throat (pharynx)

  • Voice box (larynx)

  • Windpipe (trachea)

  • Large airways (bronchi)

  • Small airways (bronchioles)

  • Lungs

The upper respiratory tract is made up of the:

  • Nose

  • Nasal cavity

  • Sinuses

  • Larynx

  • Trachea

The lower respiratory tract is made up of the:

  • Lungs

  • Bronchi and bronchioles

  • Air sacs (alveoli)

Lungs

The lungs take in oxygen. Your body's cells need oxygen to live and carry out their normal functions. The lungs also get rid of carbon dioxide, a waste product of the cells.

The lungs are a pair of cone-shaped organs made up of spongy, pinkish-gray tissue. They take up most of the space in the chest (thorax).

The lungs are surrounded by a membrane (pleura).

The lungs are separated from each other by the mediastinum, an area that contains the:

  • Heart and its large vessels

  • Trachea

  • Esophagus

  • Thymus gland

  • Lymph nodes

The right lung has 3 sections, called lobes. The left lung has 2 lobes. When you breathe in:

  • Air enters your body through your nose or mouth.

  • Air then travels down the throat through the larynx and trachea.

  • Air goes into the lungs through tubes called main-stem bronchi.

One main-stem bronchus leads to the right lung and one to the left lung:

  • In the lungs, the main-stem bronchi divide into smaller bronchi.

  • The smaller bronchi divide into even smaller tubes (bronchioles).

  • Bronchioles end in tiny air sacs (alveoli) where the exchange of oxygen and carbon dioxide occurs.

You then breathe out carbon dioxide.

Online Medical Reviewer: Daphne Pierce-Smith RN MSN
Online Medical Reviewer: Deborah Pedersen MD
Online Medical Reviewer: Marianne Fraser MSN RN
Date Last Reviewed: 4/1/2021
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