This human anatomy ClipArt gallery offers 76 illustrations of the human lower respiratory system, including organs involved in respiration. The human lower respiratory tract includes the trachea, bronchi, lungs, and diaphragm.

Left pleural sac in a subject hardened by formalin injection, opened into by the removal of the costal part of the parietal pleura. The lung has also been removed so as to display the mediastinal pleura.

Pleural Sac

Left pleural sac in a subject hardened by formalin injection, opened into by the removal of the costal…

Diagram showing arrangement of pleural sacs, as seen in transverse section.

Arrangement of the Pleural Sacs

Diagram showing arrangement of pleural sacs, as seen in transverse section.

Diagram to show the changes in the sternum, diaphragm, and abdominal wall in respiration. Labels: A, inspiration; b, expiration; Tr, trachea; St, sternum; D, diaphragm; Ab, abdominal wall. The shaded part is to indicate the stationary air

Changes during Respiration

Diagram to show the changes in the sternum, diaphragm, and abdominal wall in respiration. Labels: A,…

"The respiratory mechanism consists of the lungs, a series of minute air chambers with a network of capillaries in the wall, the air passages from the air chambers of the lngs to the outer air, and the chest walls with their muscles, which act like bellows and change the ai r in the lungs. Let us begin with the air passages. There are first the nose and mouth; these join the upper part of the gullet, known as the pharynx. From the pharnyx arises the windpipe (trachea); this passes through the voice box (larynx) into the chest cavity; there it divides into two passages (the bronchi); the bronchi go on dividing again and again, generally into two; the ultimate divisions (the bronchioles) open into clusters of air chambers."—(Charles Leonard-Stuart, 1911)

Respiratory Mechanism

"The respiratory mechanism consists of the lungs, a series of minute air chambers with a network of…

The respiratory system. Labels: 1. the larynx; 2. the trachea; 3. right bronchia; 4. left bronchia; 5. left lung divided into three lobes; 7. large bronchial tubes; 8. small bronchial tubes ending in air cells or vesicles.

Respiratory System

The respiratory system. Labels: 1. the larynx; 2. the trachea; 3. right bronchia; 4. left bronchia;…

The respiratory system. Labels: 1, larynx; 2, trachea; 3, right lung; 4, left lung; 5, heart.

Respiratory System

The respiratory system. Labels: 1, larynx; 2, trachea; 3, right lung; 4, left lung; 5, heart.

"Larynx, trachea, and bronchi, showing the manner of division, and the rings of cartilage." — Tracy, 1888

Respiratory system

"Larynx, trachea, and bronchi, showing the manner of division, and the rings of cartilage." —…

The trachea and bronchi. The thyroid body is indicated by a dotted line.

Trachea and Bronchi

The trachea and bronchi. The thyroid body is indicated by a dotted line.

Transverse section of trachea and esophagus of child, seen from below.

Transverse Section of Trachea and Esophagus

Transverse section of trachea and esophagus of child, seen from below.

"The <em>trachea</em> has in its walls stiff rings of cartilage that hold it open so that the air can pass freely through it to and from the lungs. At its base the trachea divides and sends a great branch to each lung." &mdash; Ritchie, 1918

Trachea and lungs

"The trachea has in its walls stiff rings of cartilage that hold it open so that the air can…

Transverse section of trachea, showing general arrangement of its wall.

Transverse Section of Trachea Showing Arrangement of Walls

Transverse section of trachea, showing general arrangement of its wall.

Section of the trachea. Labels: a, columnar ciliated epithelium; b and c, proper structure of the mucous membrane, containing elastic fibers cut across transversely; d, submucous tissue containing mucous glands, e, separated from the hyaline cartilage, g, by a fine fibrous tissue, f; h, external investment of fine fibrous tissue.

Section of the Trachea

Section of the trachea. Labels: a, columnar ciliated epithelium; b and c, proper structure of the mucous…

Transverse section through the trachea and its immediate surroundings at the level of each of the upper five dorsal vertebrae.

Sections Through Trachea

Transverse section through the trachea and its immediate surroundings at the level of each of the upper…

Transverse section of the trachea, just above its bifurcation, showing the carina tracheae.

Transverse Section of the Trachea

Transverse section of the trachea, just above its bifurcation, showing the carina tracheae.

Section through the humeral heads and the apices of the lungs.

Cross Section of the Trunk Through the Lungs

Section through the humeral heads and the apices of the lungs.

"A small bronchial tube and the air sacs in which it ends." &mdash; Ritchie, 1918

Bronchial tube

"A small bronchial tube and the air sacs in which it ends." — Ritchie, 1918