Lungs Flashcards
What is the location of the lung?
Either side of the thoracic cavity separated by the heart, great vessels and other mediastinal structures
The lung is attached to the mediastinum by its roots allowing it to float within the parietal pleura
How many lobes does each lung have?
Right lung = 3
Left lung = 2
What is the apex of the lung?
Upper conical part of the lung above the thoracic inlet covered by the suprapleural membrane
The apical pleura covers the apex of the lungs on all sides
Location of the lung apex
Extends up to the neck of 1st rib behind, 3-4 cms above 1st costal cartilage and 2.5 cms above medial 1/3rd of clavicle
Relations of the base of the lungs to the abdomen
Separated from the abdominal organs by the diaphragm
Right lobe of liver on the right
Stomach, spleen & left lobe of liver on the left
What are the borders of the lung?
Anterior border
Inferior border
Posterior border
What is the anterior border of the lung?
Where costal and mediastinal surfaces meet
What is the inferior border of the lung?
Separates the costal and mediastinal surface
Surrounds the diaphragmatic surface of lung
What is the posterior border of the lung?
Where the costal & mediastinal surfaces meet posteriorly
Broad & rounded
Fits into the deep paravertebral gutter (space in the thorax occupied by the lungs)
What are the surfaces of the lung?
Blunt apex
Concave base
Costal surface - Convex surface. In contact with costal pleura and overlying thoracic wall
Mediastinal surface - Irregular shape. Divided into posterior (vertebral part) and anterior (mediastinal part)
What are the relations (impressions) of the posterior part of the lung?
VIPS PIV (posterior intercostal vessels)
Vertebral Part
Intervertebral Discs
Posterior Intercostal Vessels
Splanchnic Nerves
What are the relations of the anterior part of the right lung?
Right atrium
Part of right ventricle
Superior Vena Cava
Inferior Vena Cava
Right brachiocephalic vein
Azygos vein
Right vagus nerve
Right phrenic nerve
Esophagus
Trachea
What are the relations of the anterior part of the left lung?
Left ventricle
Arch of Aorta
Descending thoracic aorta
Left Subclavian Artery
Pulmonary trunk
Left Brachiocephalic Vein
Left vagus nerve
Left phrenic nerve
Thoracic duct
What are the fissures of the lungs?
Oblique fissures
Horizontal fissures
Describe the course of the oblique fissure
Begins posteriorly at the level of the 5th thoracic vertebra and passes antero-inferiorly in a spiral course to meet the inferior margin close to the 6th costochondral junction
Describe the course of the horizontal fissue
Extends from the anterior margin at the 4th costal cartilage and runs horizontally backwards to meet the oblique fissue at the mid-axillary line
How does pulmonary pleura interact with the fissures?
It extends into the fissures of the lungs so that the lobes can move over each other during respiration
What is the hilum of the lung?
Depression in the middle of the mediastinal surface of the lungs where bronchi, vessels and nerves which form the lung root enter and leave the lung
What is the root of the lung?
Connects the medial surface of the lung to the mediastinum
It lies opposite to the 5th, 6th and 7th thoracic vertebral bodies
Describe the arrangement of structure in the right lung’s root
Superior to inferior (EPHI PEN):
* Eparterial bronchus
* Pulmonary artery
* Hyparteria bronchus
* Inferior pulmonary vein
Describe the arrangement of structure in the left lung’s root
Superior to inferior:
* Pulmonary artery
* Bronchus
* Inferior pulmonary vein
Right lung has two bronchi for 3 lobes and left lung has one bronchus for one lobe
What are bronchopulmonary segments?
They are areas of the lungs which are aerated by a segmental/tertiary bronchus
Primary bronchus enters the lungs → Divides into secondary bronchi → Divides into tertiary bronchi, each of which supplies a bronchopulmonary segment
Describe the structure of a bronchopulmonary segment
Each bronchopulmonary segment is pyramidal in shape with its apex towards the lung root
It is surrounded by connective tissue
Each has a segmental bronchus, segmental artery, lymph vessels and autonomic nerves
Segmental vein lies in the connective tissue between adjacent bronchopulmonary segments
Bronchopulmonary segments are not broncho-vascular segments because they do not have a vein of their own
What is the clinical application of bronchopulmonary segments?
Each diseased segment can be removed surgically
Right lung segment names
Upper lobe: Apical, anterior and posterior segments
Middle lobe: Medial and lateral segments
Lower lobe: Superior, anterior basal, posterior basal, medial basal and lateral basal segments
Left lung segment names
Upper lobe: Apical, posterior, anterior, superior lingular and inferior lingular segments
Lower lobe: Superior, anterior basal, medial basal, posterior basal and lateral basal segments
Explain the blood supply of the lungs
Bronchi, connective tissue and visceral pleura are supplied by bronchial arteries (branches of the descending thoracic aorta)
Bronchial veins drain into the azygos and hemiazygos veins
Alveoli receive deoxygenated blood from the pulmonary arteries and oxygenated blood from the pulmonary veins
Explain the lymphatic drainage of the lungs
Lymph vessels originate in the superficial plexus and the deep plexus & are not present in the alveolar walls
Superficial plexus lies beneath the visceral pleura & drains over the surface of lung toward hilum where lymph vessels enter bronchopulmonary nodes
Deep plexus travels along bronchi & pulmonary vessels toward hilum of lung & passes through pulmonary nodes within the lung substance; the lymph then enters bronchopulmonary nodes in the hilum of the lung
All the lymph from lung leaves hilum & drains into the tracheobronchial nodes & then into the bronchomediastinal lymph trunks
Describe the nerve supply of the lungs
Each lung is supplied by the pulmonary plexus which is formed by branches of the sympathetic trunk and parasympathetic fibers from the vagus nerve. They are located anteriorly and posteriorly relative to each lung root and in close proximity to the pulmonary arteries
Afferent impulses derived from the bronchial mucous membrane and from stretch receptors in the alveolar walls pass to the CNS in both parasympathetic and sympathetic nerves
Efferent fibres reach the bronchial muscles and glands
Bronchoconstrictor muscle is supplied by the vagus nerve
