clinical anatomy of lungs
TRANSCRIPT
Clinical Anatomy of lungs
Dr. Ashish kumar
Dept. of Chest & T.B, Santosh university
Points
1. Basic anatomy
2. Surface anatomy
3. Blood circulations
4. Innervations
5. Lymphatic
Respiratory System starts at the nares
Major Functions
Upper respiratory system:1. Air conditioning (warming)2. Defense against pathogens3. Gas Transport
Lower respiratory system:1. Speech & other
respiratory sounds2. Gas exchange (ventilation)3. Maintenance of
homeostasis, e.g. pH
Respiratory Muscles
Diaphragm: depresses on contraction inhalation
External intercostals: elevate ribs inhalation
Internal intercostals: depress ribs active exhalation
(Accessory muscles - serratus anterior, scalenes, pectoralisminor, sternocleidomastoid, internal and external obliques, transverse abdominus, rectus abdominus)
Upper Respiratory System
1. Nose
2. Nasal Cavity
3. Paranasal sinuses
4. Pharynx
Upper Respiratory System
1) Nose External and internal nares =
Nostrils Nose Hairs = vibrissae Alar cartilages on the nose Paranasal Sinuses
Upper Respiratory System
• 2) Nasal Cavity
• Nasal Conchae:
– Superior, middle and inferior
– Other name: “Turbinate bones” because they create
Upper Respiratory System
3)Paranasal Sinuses
• Named after their bones
– Frontal
– Ethmoid
– Sphenoid
– Maxillary
Upper Respiratory System
4) Pharynx
Shared passageway for respiratory and digestive systemsNasopharynx - part above uvula and posterior to internal
naresOropharynx – portion visible in mirror when mouth is wide
openfauces = the openinguvula - posterior edge of soft palate
Laryngopharynx – between the hyoid bone & the esophagus
Larynx (voice box)
The larynx consists of threearticulating cartilages,
1. Thyroid2. cricoid3. Arytenoid
Lungs
Light, soft, spongy
Conical in shape, apex, base, costal surface, medial surface, hilus. Note various impressions
Right lung
Three lobes; superior, middle and inferior
Oblique and horizontal fissure
Left Lung
Two lobes; superior and inferior also Lingula and Cardiac notch, oblique fissure
Right Lung
Left Lung
Right Lung
Lung Fissures:
Oblique fissure (Right & Left):
It starts at the 3rd thoracic spine while the arms are elevated, descends downwards, laterally & anteriorly along the medial border of the scapula touching the inferior angle of the scapula) cutting the midaxillary line in the 5th rib & ending at the 6th costal cartilage 3 inches from the midline.
In cadaver it arise at the 2nd thoracic spine.
The transverse fissure (Right):
It arises at the 4th costal cartilage, runs horizontally to meet the oblique fissure in the midaxillary line in the 5th rib.
Fissures & Lobes of the Lungs
Fissures & Lobes of the Right Lung
Right Upper Lobe
Right Middle Lobe
Right Lower lobe
Left Lung
Fissures of the Left Lung
Left Upper Lobe
Left Lower Lobe
Airways
Trachea, primary bronchi, secondary bronchi, tertiary bronchi out to 25 generations
All comprised of hyaline cartilage
Trachea
Begins where larynx ends (about C6)
10 cm long, half in neck, half in mediastinum
20 U-Shaped rings of hyaline cartilage – keeps lumen intact but not as brittle as bone
Lined with epithelium and cilia which work to keep foreign bodies/irritants away from lungs
From Bronchi to Lungs: The Bronchial Tree
1 bronchi (enter lungs at hilus, complete cartilage rings)
2 bronchi (from now on cartilage plates)
3 bronchi
Bronchioles
Terminal bronchioles
Respiratory bronchioles
Alveolar ducts
Alveolar sacs
Conducting portion
Respiratory portion
Airways
Primary Brochi One to each lung – continuation of trachea Right bronchus is wider and shorter 2.5 cm as opposed to
5 cm and branches from the trachea at a greater angle
Secondary bronchi – one to each lobe, three in right, two in left
Tertiary – one to each bronchopulmonary segment –approximately 10 per lung
All of the above are hyaline cartilage with no ability to change diameter
Bronchopulmonary Segments
Bronchopulmonary Segments
Bronchopulmonary Segments
Bronchioles
First level of airway surrounded by smooth muscle (not the cartilage ), therefore can change diameter as in brocho-constriction and broncho-dilation
Terminal
Respiratory
3-8 orders
alveoli
Bronchioles
Surface Anatomy
Borders of the lung:
The apex is about 2-3 cms (1 inch) above the medial 1/3 of the clavicle, then the anterior border of both lungs run downwards & medially meeting each other in the middle line behind the angle of Louis (sternalangle).
The anterior border of right lung continues running downwards till the 6th costochondral junction.
The anterior border of left lung continues running downwards till the 4th costal cartilage then curves laterally ½ inch forming the cardiac notch then descends downwards till the 6th costochondraljunction.
Borders of the lung:
The lower border of the lungs represented by a linestarting from 6th rib in the MCL, 8th rib in the MAL &10th rib in the scapular line.
Circulation of lungs
Two types
1. Bronchial circulation
2. Pulmonary circulation
Bronchial circulation
• The trachea (and esophagus), main-stem bronchi, and pulmonary vessels into the lung , as well as the visceral pleura in humans are supplied by the bronchial (systemic) circulation.
• The bronchial circulation has enormous growth potential. In long-standing inflammatory and proliferative diseases, such as bronchiectasis or carcinoma, bronchial blood flow may be greatlyincreased.
Pulmonary circulation
• In humans the pulmonary artery enters each lung at the hilum in a loose connective tissue sheath adjacent to the main bronchus.
• The pulmonary artery travels adjacent to and branches with each airway generation down to the level of the respiratory bronchiole.
• As blood enters the vast alveolar wall capillary network, its velocity slows, averaging approximately 1000 µm/sec (or 1 mm/sec),where gas exchange take place.
• Anatomically, the pulmonary blood vessels can be divided into two groups in
1. Extra-alveolar 2. Alveolar. Extra-alveolar
vessels lie in the loose-binding connective tissue (peribronchovascular sheaths, interlobular septa). Extra-alveolar vessels extend into the terminal respiratory units. Arteries as small as 100 µm in diameter have loose connective tissue sheaths. This is in contrast to the bronchioles, which are tightly embedded in the lung framework from the bronchioles (1 mm in diameter) onward.
Alveolar vessels lie within the alveolar walls and are embedded in the
parenchymal connective tissue
Innervation
Pleura via intercostal (thoracic) nerves.
Tracheobronchial tree motor pathway
Parasympathetic via CN X efferent function = broncho-constriction via smooth muscle, also to epithelial cells in trachea, afferent = responsible for cough reflex
Sympathetic from T1-T5 efferent = brocho-dilation
• Cholinergic, adrenergic, and peptidergic nerve Endings are present around tracheal glands and do not show patterns of slective innervation density between serous and mucous cells . Serous and mucous granule secretion is stimulated more by muscarinic than by adrenergic agents.
lymphatics
• Superficial plexuses- The superficial plexus is located n the surface of the lung just beneath the pulmonary pleura.
• Deep plexuses-accompanies the branches of the pulmonary vessels and ramifications of bronchi.
Right lung lymphatics
• Right upper lobe: • Upper 2/3rd-Right tracheobronchial nodes
• Lower l/3rd -Dorsolateral hilar nodes
• Right middle lobe: • Hilar nodes around middle lobe bronchus
• Right lower lobe: • Porsolateral part-Dorsolateral hilar nodes
• Ventromedial part- Ventromedial hilar and carinalnodes
Left lungs lymphatics
• Left upper lobe: • Apex-para-aortic node
• Other than apex-Anterior and posterior hilar nodes
• Left lower lobe • Dorsolateral part-Dorsolateral hilar nodes
• Ventromedial par^Ventromedial hilar and carinalnodes