This human anatomy ClipArt gallery offers 75 illustrations of the human lower respiratory system, including organs involved in respiration. The human lower respiratory tract includes the trachea, bronchi, lungs, and diaphragm.

"<em>A</em>, epithelial lining wall; <em>B</em>, partition between two adjacent sacs, in which run capillaries; <em>C</em>, fibers of elastic tissues." &mdash; Blaisedell, 1904

Diagrammatic view of an air sac

"A, epithelial lining wall; B, partition between two adjacent sacs, in which run capillaries;…

Two of the air sacs from the lungs with the network of blood tubes shown about one.

Air Sacs from the Lungs

Two of the air sacs from the lungs with the network of blood tubes shown about one.

Diagram of the air tubes with the lung tissue removed.

Diagram of Air Tubes in the Lungs

Diagram of the air tubes with the lung tissue removed.

Cluster of air-cells. 1: End of Bronchial Tube; 2: Air cell.

Air-Cells

Cluster of air-cells. 1: End of Bronchial Tube; 2: Air cell.

Branchi of the lungs, the heart, and blood vessels. Labels: 1, left auricle; 2, right auricle; 3, left ventricle; 5, pulmonary artery; 6, arch of the aorta; 7, superior vena cava; 8, arteria innominata; 9, left primitive carotid artery; 10, left subclavian artery; 11, trachea; 12, larynx; 13, upper lobe of right lung; 14, upper lobe of left lung; 15, trunk of right pulmonary artery; 16, lower lobes of the lungs.

Branchi and Blood Vessels

Branchi of the lungs, the heart, and blood vessels. Labels: 1, left auricle; 2, right auricle; 3, left…

Internal surface of the bronchi.

Internal Surface of the Bronchi

Internal surface of the bronchi.

The bronchia. Labels; 1, Outline of the right lung. 2, Outline of the left lung. 3, Larynx. 4, Trachea. 5, 6, 7, 8, Bronchial tubes. 9, Air-cells.

The Bronchia

The bronchia. Labels; 1, Outline of the right lung. 2, Outline of the left lung. 3, Larynx. 4, Trachea.…

View of the bronchia and veins of the lungs, exposed by dissection, as well as the relative position of the lungs to the heart.

Bronchia and Veins of the Lungs

View of the bronchia and veins of the lungs, exposed by dissection, as well as the relative position…

A small bronchial tube, a, dividing into its terminal branches, c; these have pouched or sacculated walls and end in the sacculated alveoli, b.

Bronchial Tube

A small bronchial tube, a, dividing into its terminal branches, c; these have pouched or sacculated…

A small bronchial tube. Labels: a, dividing into its terminal branches, c; these have pouched or sacculated walls and end in the sacculated infundibula, b.

A Bronchial Tube

A small bronchial tube. Labels: a, dividing into its terminal branches, c; these have pouched or sacculated…

View of the bronchial tubes, terminating in air vesicles. On the left is the external view (1, bronchial tube; 2, air vesicles). On the right is the bronchial tube and air vesicles laid open.

Bronchial Tubes Terminating in Air Vesicles

View of the bronchial tubes, terminating in air vesicles. On the left is the external view (1, bronchial…

This diagram shows the bronchial tubes, with clusters of cells. The bronchioles are the first airway branches that no longer contain cartilage. They are branches of the bronchi, and are smaller than one millimetre in diameter.

Bronchioles

This diagram shows the bronchial tubes, with clusters of cells. The bronchioles are the first airway…

Transverse section of a bronchus. Labels: e, Epithelium (ciliated); immediately beneath it is the mucous membrane or internal fibrous layer, of varying thickness; m, muscular layer; s, m, submucous tissue; f, fibrous tissue; c, cartilage enclosed within the layers of fibrous tissue; g, mucous gland.

Section of the Bronchus

Transverse section of a bronchus. Labels: e, Epithelium (ciliated); immediately beneath it is the mucous…

A front view of the chest and abdomen in respiration. Labels: 1, The position of the walls of the chest in inspiration. 2, The position of the diaphragm in inspiration. 3, The position of the walls of the chest in expiration. 4, The position of the diaphragm in expiration. 5, The position of the walls of the abdomen in inspiration. 6, The position of the abdominal walls in expiration.

A Front View of the Chest and Abdomen in Respiration

A front view of the chest and abdomen in respiration. Labels: 1, The position of the walls of the chest…

A side view of the chest and abdomen in respiration. Labels: 1, The cavity of the chest. 2, The cavity of the abdomen. 3, The line of direction for the diaphragm when relaxed in expiration. 4, The line of direction for the diaphragm when contracted in inspiration. 5, 6, The position of the front walls of the chest and abdomen in inspiration. 7, 8, The position of the front walls of the abdomen and chest in expiration.

A Side View of the Chest and Abdomen in Respiration

A side view of the chest and abdomen in respiration. Labels: 1, The cavity of the chest. 2, The cavity…

Structure of the chest, showing the framework of the bones which are connected together chiefly by muscles. It is important to understand the structure of the chest in order to understand how the movements of the chest are made in inspiration and expiration. The spinal column <em>b,b</em> is the grand pillar that supports this barrel-shaped framework. The ribs <em>c, c, c</em> are fastened very strongly by ligaments to the spinal column. They are 2 in number, 12 on each side and extend round towards the breast bone (sternum) <em>a</em> in front.

Structure of the Chest

Structure of the chest, showing the framework of the bones which are connected together chiefly by muscles.…

View of the diaphragm; 1, cavity of the thorax; 2, diaphragm separating the cavity of the thorax from that of the abdomen; 3, cavity of the pelvis.

Diaphragm

View of the diaphragm; 1, cavity of the thorax; 2, diaphragm separating the cavity of the thorax from…

Diaphragm in the state of its greatest ascent in expiration; 2, muscles of the abdomen in action forcing the viscera and diaphragm upwards.

Diaphragm During Expiration

Diaphragm in the state of its greatest ascent in expiration; 2, muscles of the abdomen in action forcing…

Diaphragm in its state of greatest descent in inspiration; 2, muscles of the abdomen, showing the extend of their protrusion in the action of inspiration.

Diaphragm During Inspiration

Diaphragm in its state of greatest descent in inspiration; 2, muscles of the abdomen, showing the extend…

The diaphragm, seen from above.

Diaphragm Viewed from Above

The diaphragm, seen from above.

The diaphragm, viewed from below.

Diaphragm Viewed from Below

The diaphragm, viewed from below.

The diaphragm, viewed from in front.

Diaphragm Viewed from Front

The diaphragm, viewed from in front.

The diaphragm, which is the principal muscle that act sin breathing. Here you have the cavity of the chest, <em>Cc</em>, laid open, the ribs being cut away in front, and the heart and lungs taken out; <em>DD</em> is the diaphragm. It is fastened to the spinal column behind, to the breast-bone in front, and to the lower ribs all around its side. It is not flat, but arched upward.

The Diaphragm

The diaphragm, which is the principal muscle that act sin breathing. Here you have the cavity of the…

Diaphragm of the diaphragm and it's placement in the chest. Let <em>a</em> represent the spinal column, <em>b</em> the front wall of the chest, <em>Cc</em> the cavity of the chest, and <em>Ca</em> the cavity of the abdomen. At <em>d</em> is represented the diaphragm. As you can see from the figure, as the fibers of the diaphragm are shortened the space in the chest increases which is what takes place during inspiration. On the contrary, during expiration the diaphragm is pushed upward as shown in this figure so the room in the chest is lessened and air is forced out.

The Diaphragm

Diaphragm of the diaphragm and it's placement in the chest. Let a represent the spinal column,…

Expiration. 1: Diaphragm.

Expiration

Expiration. 1: Diaphragm.

Two small infundibula or groups of air cells, a, with air cells, b, and the ultimate bronchial tubes, c, with which the air cells communicates. From a newborn child.

Infundibula

Two small infundibula or groups of air cells, a, with air cells, b, and the ultimate bronchial tubes,…

Two infundibula of the lung much magnified. Labels: b, b, hollow protrusions of the alveolus, opening into its central cavity; c, terminal branches of a bronchial tube.

Infundibula of the Lung

Two infundibula of the lung much magnified. Labels: b, b, hollow protrusions of the alveolus, opening…

Inspiration. 1: Diaphragm; 2: Sternum.

Inspiration

Inspiration. 1: Diaphragm; 2: Sternum.

"Section of a pulmonary lobule, showing its division into pulmonary vesicles." &mdash; Tracy, 1888

Pulmonary lobule

"Section of a pulmonary lobule, showing its division into pulmonary vesicles." — Tracy, 1888

Diagram of the two primary lobules of the lungs, magnified. Labels: 1, Bronchial tube. 2, A pair of primary lobules connected by elastic tissue. 3, Intercellular air-passages. 4, Air-cells. 5, Branches of the pulmonary artery and vein.

Diagram of the Two Primary Lobules of the Lung

Diagram of the two primary lobules of the lungs, magnified. Labels: 1, Bronchial tube. 2, A pair of…

"Showing the structure of a lobule of the lung. The lobule has been injected with mercury, afterwards dried and cut open. A large bronchial tube with its various branches is well shown." &mdash; Blaisedell, 1904

Lobule of a Lung

"Showing the structure of a lobule of the lung. The lobule has been injected with mercury, afterwards…

Section of lung, showing small air tubes and branch of pulmonary artery.

Section of Lung Showing Air Tubes

Section of lung, showing small air tubes and branch of pulmonary artery.

Section of lung, showing general relations of division of air tubes.

Section of Lung Showing General Relations of Divisions of Air Tubes

Section of lung, showing general relations of division of air tubes.

"<em>A</em>, an air sac; <em>B</em>, an air sac cut open; <em>C</em>, capillary network over an air sac; <em>D</em>, branch of pulmonary artery; <em>E</em>, branch of pulmonary vein; <em>F</em>, bronchial tube." &mdash; Blaisedell, 1904

Lobule of the lung

"A, an air sac; B, an air sac cut open; C, capillary network over an air…

Mediastinal surface of right lung.

Mediastinal Surface of the Lung

Mediastinal surface of right lung.

Mediastinal surface of left lung.

Mediastinal Surface of the Lung

Mediastinal surface of left lung.

The right lung. The outer or costal surface.

Outer Surface of the Lung

The right lung. The outer or costal surface.

"Lobules of various sizes are well shown." &mdash; Blaisedell, 1904

Portion of a child's lung

"Lobules of various sizes are well shown." — Blaisedell, 1904

Section of lung with distended blood vessels, highly magnified. Labels: c,c, partitions between alveoli; b, small artery giving off capillaries to alveoli.

Section of Lung

Section of lung with distended blood vessels, highly magnified. Labels: c,c, partitions between alveoli;…

Diagram showing human lungs, heart, and throat.

Lungs

Diagram showing human lungs, heart, and throat.

"<em>L.A.</em>, left ventricle; <em>B</em>, right ventricle; <em>F</em>, pulmonary artery; <em>G</em>, aorta; <em>H</em>, arch of the aorta; <em>K</em>, innominate artery; <em>L</em>, right common carotid artery; <em>M</em>, right subclavian artery; <em>N</em>, thyroid cartilage forming upper portions of the larynx; <em>O</em>, trachea." &mdash; Blaisedell, 1904

Lungs

"L.A., left ventricle; B, right ventricle; F, pulmonary artery; G,…

"<em>A</em>, division of left bronchus to upper lobe; <em>B</em>, left branch of the pulmonary artery; <em>C</em>, left bronchus; <em>D</em>, left superior pulmonary vein; <em>E</em>, left inferior pulmonary vein; <em>F</em>, left auricle; <em>K</em>, inferior vena cava; <em>L</em>; division of the right bronchus to lower lobe; <em>M</em>, right inferior pulmonary vein; <em>N</em>, right superior pulmonary vein, <em>O</em>, right branch of the pulmonary artery; <em>P</em>, division of right bronchus to upper lobe; <em>R</em>, left ventricle; <em>S</em>, right ventricle." &mdash; Blaisedell, 1904

Lungs

"A, division of left bronchus to upper lobe; B, left branch of the pulmonary artery;…

"Relative Postion of the Lungs, the Heart, and Some of the Great Vessels belonging to the latter. <em>A</em>, left common carotid artery; <em>B</em>, external carotid artery; <em>C</em>, internal carotid artery; <em>D</em>, left jugular vein; <em>E</em>, sterno-cleido muscle; <em>F</em>, right innominate artery with branches to head and arm; <em>G</em>, left subclavian artery; <em>H</em>, great azygos vein; <em>K</em>, thoracic duct." &mdash; Blaisedell, 1904

Lungs

"Relative Postion of the Lungs, the Heart, and Some of the Great Vessels belonging to the latter. A,…

The lung is the essential organ of respiration in air-breathing vertebrates. Its principal function is to transport oxygen from the atmosphere into the bloodstream, and excrete carbon dioxide from the bloodstream into the atmosphere.

Lungs

The lung is the essential organ of respiration in air-breathing vertebrates. Its principal function…

Ideal diagram of lungs and air-passages.

Lungs

Ideal diagram of lungs and air-passages.

"The Lungs. 1, Summit of lungs. 2, Base of lungs. 3, Trachea. 4, Right bronchus. 5, Left bronchus. 6, Left aurical of heart. 7, Left superior pulmonary vein. 8, Right superior pulmonary vein. 9, Left ventricle of heart. 10, Right ventricle of heart." -Foster, 1921

Lungs

"The Lungs. 1, Summit of lungs. 2, Base of lungs. 3, Trachea. 4, Right bronchus. 5, Left bronchus. 6,…

The lungs in position.

Lungs

The lungs in position.

The lungs. Labels: 3, The lobes of the right lung. 4, The lobes of the left lung. 5, 6, 7, The heart. 9, 10, 11, The large blood-vessels. 12, The trachea. 15, The diaphragm.

The Lungs

The lungs. Labels: 3, The lobes of the right lung. 4, The lobes of the left lung. 5, 6, 7, The heart.…

The lungs and air passages seen from the front. On the left of the figure the pulmonary tissue has been dissected away to show the ramifications of the bronchial tubes. Labels: a, larynx; b, trachea; d, right bronchus. The left bronchus is seen entering the root of its lung.

Lungs and Air Passages

The lungs and air passages seen from the front. On the left of the figure the pulmonary tissue has been…

The lungs and air passages seen from the front. On the left of the figure the pulmonary tissue has been dissected away to show the ramifications of the bronchial tubes. Labels: a, larynx; b, trachea; d, right bronchus. The left bronchus is seen entering the root of its lung.

The Lungs and Air Passages

The lungs and air passages seen from the front. On the left of the figure the pulmonary tissue has been…

Anterior view of the lungs and heart. Labels: 1, heart; 2, inferior vena cava; 3, superior vena cava; 4, right innominate vein; 5, left innominate vein; 6, jugular vein; 7, subclavian vein; 8, arch of aorta; 8', subclavian artery; 9, left pulmonary artery; 9', 9', carotid artery; 10, trachea; 11, left bronchus; 12, ramifications of right bronchus exposed in upper lobe of right lung; 13, 14, middle lobe; 15, lower lobe; 16, upper lobe of left lung; 17, lower lobe of left lung.

Anterior View of the Lungs and Heart

Anterior view of the lungs and heart. Labels: 1, heart; 2, inferior vena cava; 3, superior vena cava;…

The lungs and windpipe (trachea). Labels: 1, larynx; 2, windpipe (trachea); 3, right lung, showing bronchi and bronchial tube.

Lungs and Trachea

The lungs and windpipe (trachea). Labels: 1, larynx; 2, windpipe (trachea); 3, right lung, showing bronchi…

Costal surfaces of the two lungs. A, right lung. B, left lung.

Costal Surfaces of the Lungs

Costal surfaces of the two lungs. A, right lung. B, left lung.

Mediastinal surfaces of the two lungs of a subject hardened by formalin injection. A, right lung. B, left lung. Labels: a, base; 2, fissure; 3, cardiac depression; 4, groove for innominate vein; 5, groove for innominate artery; 6, apex pulmonis; 7, groove for vena azygos major; 8, eparterial bronchus; 9, pulmonary artery (right); 10, fissure; 11, groove for aorta; 12, bronchus; 13, pulmonary artery (left); 14, apex pulmonis; 15, groove for left subclavian artery; 16, groove for left innominate vein; 17, cardiac depression; 18, fissure; 19, base.

Mediastinal Surfaces of the Lungs

Mediastinal surfaces of the two lungs of a subject hardened by formalin injection. A, right lung. B,…

Diagram showing the structure of the lungs. At <em>d</em> is the left lung, and at <em>c</em> are represented the main branch of the windpipe that go to the right lung, separated by the lung itself. At the lower part, at <em>e</em>, are represented the very minute branches as they go to the air-cells (alveoli). At <em>b</em> is the windpipe (trachea), and at <em>a</em> is the larynx (or Adam's apple). It is through a chink in this that air passes in and out as we breathe.

Structure of the Lungs

Diagram showing the structure of the lungs. At d is the left lung, and at c are represented…

Structure of the lung. The lung has a serous coat; a sub-serous, elastic areolar tissue, investing the entire organ, and extending inward between the lobules; and the parenchyma, or true lung-tissue, composed of lobules and alveoli (or air-cells).

Structure of the Lungs

Structure of the lung. The lung has a serous coat; a sub-serous, elastic areolar tissue, investing the…

"The lungs fill up most of the cavity of the chest. One lies on either side of the heart which is in the middle of the chest. The lungs in animals are called lights because they are spongy sacs and so light as to float when thrown into water." &mdash;Davison, 1910

The lungs

"The lungs fill up most of the cavity of the chest. One lies on either side of the heart which is in…

The lung, which are the two essential organs of respiration contained in the cavity of the thorax.

The Lungs

The lung, which are the two essential organs of respiration contained in the cavity of the thorax.

The dome of the pleura.

Pleura

The dome of the pleura.

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…