human respiratory system

Introduction
The design of the respiratory system
- Morphology of the upper airways
  - The nose
  - The pharynx
- Morphology of the lower airways
  - The larynx
  - The trachea and the stem bronchi
- Structural design of the airway tree
- The lungs
  - Gross anatomy
  - Pulmonary segments
  - The intrapulmonary conducting airways: bronchi and bronchioles
  - The gas-exchange region
  - Blood vessels, lymphatic vessels, and nerves
  - Lung development
Control of breathing
- Central organization of respiratory neurons
- Chemoreceptors
  - Peripheral chemoreceptors
  - Central chemoreceptors
  - Muscle and lung receptors
- Variations in breathing
  - Exercise
  - Sleep
The mechanics of breathing
- The lung–chest system
- The role of muscles
- The respiratory pump and its performance
Gas exchange
- Transport of oxygen
- Transport of carbon dioxide
- Gas exchange in the lung
- Abnormal gas exchange
Interplay of respiration, circulation, and metabolism
Adaptations
- High altitudes
- Swimming and diving

References & Edit History Related Topics

Images, Videos & Interactives

Medical illustration of the human chest showing the lungs, diaphragm, ribs, trachea, bronchus, and bronchioles, with one lung cut away to reveal internal structures.

Passage of air through the respiratory tract explained

Medical illustration showing a sagittal section of the human head focused on the nasal cavity, with labeled parts including the frontal and sphenoid sinuses, ethmoid bone, conchae, nasal vestibule, oral cavity, soft palate, anterior nasal spine, and tongue.

human body systems interactive - respiratory

A swimmer wearing goggles and a swim cap turns their head to breathe while swimming in open water, emphasizing the act of breathing during exercise.

A labeled medical illustration shows a sagittal section of the pharynx, highlighting anatomical features such as the tonsils, palate, tongue, epiglottis, and related muscles. An inset diagram identifies the nasal, oral, and laryngeal regions of the pharynx in color.

Educational diagram showing the human voice-producing apparatus, including a side view of the head and neck with labeled tongue, larynx, vocal cords, and trachea, plus a top-down view of the vocal cords during inhalation and sound production. Labels explain the roles of resonators, vocal cord positioning, and cartilage structures in speech.

Medical image showing a detailed view of healthy human lungs, highlighting the trachea, bronchi, and branching bronchioles within the chest.

Why sleep is so important

diaphragm; breathing

At a Glance

default image

respiratory system summary

Related Questions

Medical illustration of the human chest showing the lungs, diaphragm, ribs, trachea, bronchus, and bronchioles, with one lung cut away to reveal internal structures. — human lungs The lungs serve as the gas-exchanging organ for the process of respiration.

human respiratory system

physiology

Written by

Arthur A. SiebensAll

Fact-checked by

Britannica Editors

Last updated

Sep. 26, 2026 •History

human respiratory system, the system in humans that takes up oxygen and expels carbon dioxide. The human gas-exchanging organ, the lung, is located in the thorax, where its delicate tissues are protected by the bony and muscular thoracic cage. The lung provides the tissues of the human body with a continuous flow of oxygen and clears the blood of the gaseous waste product, carbon dioxide. Atmospheric air is pumped in and out regularly through a...

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