Pulmonary Flashcards
What are the two layers of pleura?
Visceral and parietal
At what point is each pleural layer continuous?
The hilum
What is a pleural cavity
Normally surface tension holds 2 pleura layers close together so potential space exists between parietal and visceral pleura. Contains small amount of serous fluid
Innervation of parietal pleura
Phrenic or intercostal nerves depending on region (the diaphragmatic and mediastinal pleura is mainly innervated by the phrenic nerves, while the costal pleura is innervated by the intercostal nerves).
What are pleura. What sort of cell does it entail?
Serous membranes that line the lungs and thoracic cavity. (simple squamous cells)
Which layer of pleura is thicker?
Parietal
What are functions of pleural serous fluid?
1) Lubricates surfaces of pleura, allowing them to slide over each other
2) Produces surface tension, pulls 2 pleura layers closer together
What is the costodiaphragmatic recess?
The lung does not fill the pleural cavity completely during normal breathing, the parietal pleura forms costodiaphragmatic recesses between thoracic wall (costal pleurae) and diaphragm (diaphragmatic pleurae) into which the lung can expand during deep inspiration.
Why is the recess clinically significant?
Knowledge of these pleural recesses is important, as they are a site of potential fluid accumulation (pleural effusion). Any procedure crossing the costodiaphragmatic recess risks lung damage and pneumothorax.
What is a pneumothorax?
Collection of air within pleural cavity surrounding lung, resulting in lung collapsing as surface tension breaks and negative pressure lost.
Where does bronchial tree start?
Trachea, C6 below cricoid cartilage
What marks the bifurcation of the trachea?
At carina (T4/sternal angle). Divides in into Left and Right Primary Bronchi.
What is the trachea lined with?
Respiratory epithelium acting as escalator wafting particulate matter up out of airways.
What is benefit of hyaline cartilage rings of trachea being incomplete posteriorly?
1) permits expansion of oesophagus
2) provides attachment for trachealis muscle, which narrows ariways during coughing.
What is the purpose of fibroelastic tissue between cartilage in trachea?
Assists smooth muscle in varying tracheal diameter in forced respiration
Describe innervation of trachea?
Parasympathetic from vagus (recurrent laryngeal) and sympathetic from chain
Which artery supplies the trachea?
Inferior thyroid
Which nodes drain trachea?
Postoinferior deep cervical nodes
What’s the difference between bronchi and why is this clinically significant?
Right bronchus wider, more vertical and shorter. More vertical therefore more likely to be obstructed by an inhaled object.
What level do bronchi enter hilum?
T5/6
Difference in bronchus lung entry (between left and right)
Right gives off superior branch of lobar bronchus before it enters the lung.
What happens to the bronchi inside lungs?
Each divides into lobar/secondary bronchi
What do the secondary bronchi supply?
Lobes
What happens to the secondary bronchi inside the lungs?
Divides into tertiary/segmental bronchi
What do tertiary bronchi supply? (how many on left and right)
Bronchopulmonary segment, 10 right lung, 8-10 left lung.
What happens to tertiary bronchi
Divide to form bronchioles
What happens to bronchioles?
Divide to form 5-6 terminal bronchioles
What happens to terminal bronchioles?
From 2-5 respiratory bronchioles
What do respiratory bronchioles form?
2-11 alveolar ducts
Describe right lung lobes and fissures?
Superior, inf and middle lobe
Middle and inf separated by oblique fissure
Middle and superior separated by horizontal fissure
Describe lobes and fissures of left lung
Superior and inferior lobes divided by oblique fissure
E: lingular lobe (remnant of middle lobe on left side)
What are the 3 borders of lung?
Anterior: costla and mediastinal surface
Inferior: diaphragmatic surface
Posterior: costal and mediastinal
What is special about anterior border of left lung?
Marked by cardiac notch (on medial surface where lateral heart border indents)
What is the hilum?
Where all pulmonary vessels, lypmh vessels, nerve, bronchial vessels and bronchi enter lung through
What are the external markings of the lung?
T6 - midclavicular line
T8 - mid axillary
T10 -posterior
Describe arrangement of structures in hilum
medial lateral
Pulmonary artery
Bronchi
Pulmonary veins
Describe para innervation of lung
From vagus innervate smooth muscle and secretory glands in/of bronchial tree and pulmonary vessels
Carry sensation from stretch receptors in bronchial muscles, interalveolar connective tissue and baroreceptors in pulmonary artery / chemoreceptors in pulmonary veins.
Describe role of sympathetic fibres in innervation of lung
From T1-T5 sympathetic ganglia.
Innervate smooth muscle of bronchial tree and pulmonay vessels and secretory glands of bronchial tree
What do the bronchial arteries supply?
Bronchi, lung roots, visceral pleura etc
What do bronchial veins drain into?
Right bronchial vein drains into azygous vein
Left vein drains into accessory hemiazygous vein
Describe the lymphatic drainage of the lungs
Bronchopulmonary lymph nodes at hilum receive lymh from supeperficial and deep lymphatic plexi
What do bronchopulmonary nodes drain lymph to?
Tracheobronchial lymph nodes surrounding tracheal bifurcation which drain into paratracheal nodes.
Where is lymphatic drainage from right lung, lower left lobe received by?
Right lymphatic duct
Where is lymphatic drainage from superior left lobe drained to?
Thoracic duct
Where does the trachea begin?
Lower border of cricoid cartilage
Is cricoid inferior or superior to thyroid cartilage?
Inferior
Where does the trachea bifurcate?
T4 sternal angle
