Body system

Respiratory Anatomy Diagrams

Labeled diagrams of the respiratory system — the upper airway, larynx, trachea and bronchial tree, lungs, alveoli, and the muscles of breathing — drawn for lecture slides, revision, and airway teaching.

The respiratory system moves air from the nose and mouth to the alveoli, where oxygen crosses into the blood and carbon dioxide leaves it. Anatomically it divides into a conducting zone (nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles) that warms, filters and carries air, and a respiratory zone (respiratory bronchioles, alveolar ducts, alveoli) where gas exchange actually happens. The diagrams on this page follow that order, from the upper airway down to the alveolar capillary bed.

For airway teaching in particular, the useful figures are the ones that show relationships rather than every detail: how the tongue, epiglottis and glottis line up in the sagittal plane, where the trachea divides at the carina, and why the right main bronchus is the more likely destination for an endotracheal tube that has been advanced too far. Each figure below is available labeled, for the first pass through a topic, and unlabeled, for a quiz or a whiteboard-style walkthrough.

All of these are vector drawings. They scale cleanly to a projector or a printed handout, and every label can be edited, translated, or removed in the editor, so the same base figure serves an introductory lecture and a specialist session.

Diagrams in this system

What each diagram shows and how to teach with it

Lungs

Both lungs in anterior view with the trachea and main bronchi entering at the hila. The right lung shows its three lobes and the horizontal fissure; the left shows two lobes and the cardiac notch. The diaphragm is indicated below.

In the lecture

The standard opening figure for any respiratory lecture. Use it to establish the asymmetry between the lungs — three lobes against two, and the left lung's accommodation of the heart — before moving to the bronchial tree. In a clinical session it anchors discussion of lobar pneumonia, pneumothorax, and where to auscultate each lobe.

Trachea and bronchi

The trachea with its C-shaped cartilage rings, dividing at the carina into the right and left main bronchi. The right main bronchus is drawn wider and more vertical, as it is in life.

In the lecture

This is the figure to have on screen when explaining endotracheal tube placement. The right main bronchus is shorter, wider, and departs the trachea at a shallower angle, which is why a tube advanced too far almost always enters the right side and why a right-sided-only chest rise after intubation means the tube needs to come back. The cartilage rings are also why the trachea stays open under negative pressure while the oesophagus behind it collapses.

Alveoli

A cluster of alveoli at the end of a respiratory bronchiole, wrapped in the pulmonary capillary network, with the direction of oxygen and carbon dioxide exchange marked.

In the lecture

Use this to move from anatomy to physiology. The point to make is the thinness of the blood–gas barrier — a single alveolar epithelial cell, a fused basement membrane, and a capillary endothelial cell — and the enormous combined surface area. It also sets up the discussion of ventilation–perfusion matching and of conditions that thicken the barrier or flood the alveolus.

Frequently asked questions