Anatomy respiration III - Pleurae, lungs and tracheobronchial tree

Pleural sleeve

Where the parietal and visceral pleura meet. It covers the root of the lung.

Parietal wall is separated from the thoracic cavity by the __________ and what's its clinical importance

endothoracic fascia and it is forms a natural cleavage plane for the surgical separation of the costal plerua from the thoracic wall.

Four parts of the parietal pleura

1. Costal - covers the internal surfaces of the thoracic wall 2. Mediastinal - covers the lateral aspects of the mediastinum 3. Diaphragmatic covers the superior surface of the diaphragm, except at the costal origins and the part which is attached to the pericardium. The diaphragmatic pleura attaches to the diaphragm by the phrenicopleural fascia. 4. Cervical - covers the apex of the lungs. Goes above the superior thoracic aperture, above the clavicle, into the root of the neck. Cervical extension of the endothoracic fascia is the suprapleural membrane.

Structure of the right lung (size, shape, fissures, grooves)

1. Horizontal and oblique fissure separating the lung into superior, middle and inferior lobes. 2. It is larger and heavier (625g) than the left. 3. Shorter and wider than the left because the diaphragm is higher on the right side and the heart bulges more to the left. 4. Grooves on the mediastinal surface - Esophagus - runs superoinferiorly posterior to the hilum - Trachea - superior to the hilum - Brachiocephalic - anterior to the hilum, continues as the superior vena cava - Arch of azygous vein - Branch from the brachiocephalic vein Curves around the hilum and then the azygous vein continues inferiorly behind the hilum and esophagus. - Cardiac impression - anteroinferior to the hilum. It's of the right atrium and right ventricle. - Inferior vena cava - inferior to the hilum, posteroinferior to the cardiac impression 5. The diaphragmatic surface of the right lung is more concave than the left because the right part of the diaphragm overlies the liver. 6. Right vagus, runs near the groove of the brachiocephalic vein to the superior aspect of the hilum, and right phrenic nerve, which runs in front of the hilum to the inferior border.

Two membranes that make up the plerual sac and what does each cover

1. Parietal - Pulmonary cavity 2. Visceral pleura - All surfaces of the lungs The connect to each other at the hilum

Divisions of the tracheobronchial tree

1. Principle bronchi - Right: runs more vertically and is shorter - Left: runs inferolaterally, inferior to the arch of the aorta and anterior to the esophagus and thoracic aorta 2. Secondary lobar bronchi: Two in the left and three in the right, one for each lobe. 3. Tertiary segmental bronchi 4. Terminal bronchioles: Bronchioles lack cartilages in their walls. 5. Respiratory bronchioles 6. Alveolar ducts 7. Alveoli

What is it called with the pleural space fills with: 1. Pus 2. Water 3. Air 4. Blood

1. Pyothorax 2. Hydrothorax 3. Pneumothorax 4. Hemothorax

Structure of the left lung

1. Single oblique fissure dividing the lung into superior and inferior lobes. 2. Cardiac notch on the anterior surface. It mostly indents the superior lobe. Lingula - Due to the cardiac notch indentation. It slides in and out of the costomediatinal recess during inspiration and expiration. 3. Gooves on the mediastinal surface - Arch of the aorta and descending aorta - Left common carotid artery - Subclavian artery - Esophagus 4. Left vagus and left phrenic nerve, with the phrenic running anteriorly to the hilum. 5. Cardiac impression of the right ventricle, left ventricle and left auricle. It is separated from the heart by the phrenic nerve and the pericardium.

Components of the vertebral surface

1. Thoracic vertebra 2. Intervertebral discs 3. Sympathetic chain 4. Splanchnic nerves

Surface anatomy of the lung

Anterior and inferior border of the pleura: Starts above the medial 1/3 of the clavicle. Passes over the sternoclavicular joint and meets at the 2nd rib mid sternum.. just above the sternomandibular joint. Diverage at rib 4. The right pleura is still parasternal at rib 6. Both are at the midclavicular line at rib 8. Rib 10 axillary line and are at the 12th rib at the scapular plane. (2,4,6,8,10,12) Posterior border of the lung: 6th rib midclavicular line, axillary line rib 8 and 10th rib scapular plane. This is 2 ribs above the inferior border of the parietal pleura.

Relations of the lun

Apex: Laterally there is the scalenous medius muscle, medially the trachea, anteriorly the subclavian artery and posteriorly the neck of the 1st rib, sympathetic chain, superior intercostal chain Base: Right lung has the right dome of the diaphragm and the right lobe of the liver. Left has the left lobe of the liver, fundus of the stomach and the spleen. Costal: Ribs and intercostal spaces

Pulmonary ligament

Continuity between the parietal and visceral pleura. Extends between the lung and the mediastinum immediately anterior to the esophagus.

What's the costodiaphragmatic recess

It's a space in the pleural cavity where the diaphragmatic pleura is on contact with the lowermost parts of the costal pleura. It's present from the 8-10th rib at the mid acillary line.

Innervation of the lungs and its effects

Nerves are derived from the pulmonary plexus. It contains parasympathetic, sympathetic and visceral afferent fibers. Parasympathetic: Contains presympathetic fibers from the vagus - bronchoconstriction (motor), vasodilatory (inhibitory), glands of bronchial tree (secretory) Sympathetic: Contains post sympathetic fibers causing bronchodilation (inhibitory), vasoconstrictor (motor)

Clinical correlate of the costodiaphragmatic recess

Pleural exudate can collect here and it can be collected from here if there's a pleural effusion. The needle would be passed through the 6th intercostal space.

Vasculature of the lungs

Pulmonary arteries: Supply the visceral pleura and supporting tissues of the lung - Pulmonary arteries arise form the pulmonary trunk - Branch into lobar arteries and further segments one for each lobe Pulmonary veins - Lobar and segmental veins Bronchial arteries - The two left bronchial arteries usually arise from the thoracic aorta - The single right bronchial artery usually arises from a common trunk with the left superior bronchial artery or the upper posterior intercostal arteries.

Epithelium of the bronchi

Respiratory epithelium: Principal bronchi to segmental bronchi Cuboidal: Terminal bronchioles Simple squamous: Respiratory bronchioles to alveoli

What is between the two pleural layers and what's its function

Serous pleural fluid and it provides cohesion that allows the lung surface to stay in contact with the thoracic wall and consequently it allows sliding to occur.

Lymphatic drainage of the lungs

Superficial: The subpleural plexus lies deep to the visceral pleura drains into the hilar (bronchopulmonary) lymph nodes. It drains the lung parenchyma and visceral pleura. Deep: Bronchopulmonary lymphatic plexus is located in the submucosa of the bronchi and in the peribronchial connective tissue. It drains the root of the lung. Parietal plerura: Drains into the throacic wall Passage: 1. Bronchopulmonary lymphatic plexus drains into the pulmonary lymph nodes and then into the bronchopulmonary lymph nodes along with the subpleural plexus. 2. These then drain into the superior and inferior tracheobronchial lymph nodes, these are next to the biforcation of the trachea. 3. Lymph from the tracheobronchial lymph nodes drain into the bronchomediastinal lymph trunks. The right one can form the right lymphatic duct and the left terminates in the thoracic duct.

Bronchopulomonary segments

Supplied by the segmental bronchi and tertiary branch of the pulmonary artery Right: 3 lobes - Superior lobe: Apical, anterior, and posterior - Middle lobe: Lateral and medial - Inferior: Superior, anterior basal, medial basal, lateral basal and posterior basal Left: 2 lobes - Superior lobe: Apical, posterior, anterior, superior lingular, inferior lingular

What is the costomediastinal recess

The pleural space formed by the contact between the costal and mediastinal pleura. Anterior border of the lung completely occupies this recess.

Clincal significance of bronchopulmonary segments

They are surgically resectable. For example, TB usually presents in the upper lobes of the right lung. The right lung is more susceptible to infection because the right principal bronchus is shorter, wider and more horizontal.

Hilum of the right lung

This is where the structures forming the root of the lung pass. They are oriented differently in the right and left lung.