1. Breathing Flashcards
What can be found at the level of sternal angle?
- Division of superior and inferior mediastinum
- Bifurcation of the trachea
- Starting and ending point of the aortic arch
- T4/T5 intervertebral disc
- starting point of thoracic aorta
- Ligamentum arteriosum
- loop of left recurrent laryngeal nerve
What does the caval opening of the diaphragm contain?
Location: at the central tendon
- Inferior vena cava
- phrenic nerve
What does the oesophageal opening of the diaphragm contain?
Location: Muscular part of diaphragm
- Oesophagus
- Vagus nerve
- Branches of gastric vessels
- Lymphatics
What does the aortic opening of the diaphragm contain?
Location: Muscular part
- Aorta
- Azygos vein
- Thoracic duct (lymphatic drainage)
What is the blood supply of the diaphragm?
Abdominal aorta -> Inferior phrenic A/V
Internal thoracic artery -> Musculophrenic A/V
What is the nerve innervation of the visceral pleura?
Pulmonary plexus (T2-T5, vagus nerve CNX)
What is the nerve innervation of the parietal pleura?
Intercostal nerve
Exception: central diaphragmatic and mediastinal pleura
Innervated by phrenic nerve
What does hilum of lungs consist of?
- Pulmonary arteries
- Pulmonary veins
- Pulmonary plexus
- Lymph nodes
- Bronchus
- Bronchial arteries and veins
What is the artery, vein and nerve that runs anterior to the hilum of lungs?
Pericardiocophrenic A/V
Phrenic nerve
Where are the pulmonary artery, bronchus and pulmonary veins in the hilum?
(Left and right lung respectively)
Mnemonic: RALS
In right lung: pulmonary artery is anterior to the bronchus
In left lung: pulmonary artery is superior to the bronchus
Pulmonary veins are inferior to pulmonary artery and bronchus
5 lobes of the lung
Three Right Lobes (RUL, RML, RLL)
Two Left Lobes (LUL, LLL)
Where is the visceral pleura/lung in the mid-clavicular line and mid-axillary line?
MCL: 6th rib
MAL: 8th rib
Where is the parietal pleura in the mid-clavicular line and mid-axillary line?
MCL: 8th rib
MAL: 10th rib
Where is the visceral pleura/lungs and parietal pleura in posterior paravertebral line?
Visceral pleura/lungs: 10th rib
Parietal pleura: 12th rib
Where is posterior median line (PML) and posterior paravertebral line (PL)?
PML: Line that transects through the mid of vertebral column
PL: Line that is 1 inch lateral to PML
Lymphatic drainage of the lungs
Subpleural lymphatic plexus (superficial lymph nodes) -> pulmonary nodes -> bronchopulmonary nodes -> tracheobronchial nodes -> paratracheal nodes
-> thoracic duct (left)
-> right lymphatic duct (right)
-> brachialcephalic vein -> superior vena cava -> right atrium
Parts of the sternum
Manubrium, body, xiphoid process
How to differentiate between type 1 and 2 pneumocytes in microscopic view?
Type 1 pneumocytes are squamous epithelial cells while type 2 pneumocytes are cuboidal epithelial cells.
Presence of multilamellar bodies in type 2 pneumocytes but not in type 1.
What are the parts of a typical rib?
Head, Body (tubercle, neck, costal groove, neck), Costal Cartilage
What does the costal groove contain?
Intercostal vein, artery, nerve (VAN)
Where are the articular facets in the ribs?
2 at the crest (head) - bodies of thoracic vertebraeJ , 1 at the tubercle - transverse process of thoracic vertebrae
Physiological process of inspiration
- Diaphragm and intercostal muscles contract
- Thorax expand
- Intrapleural decrease (subatmospheric)
- Incrrease transpulmonary pressure
- Lung Volume increase
- Alveolar pressure decrease (subatmospheric)
- Air is sucked in due to pressure difference
What is intrapleural, alveolar and transpulmonary pressure?
Intrapleural: Pressure within pleural cavity
Alveolar: Pressure of air inside lung alveoli
Transpulmonary: Pressure difference between pleural space and alveloar space
What is pneumothorax?
Air leaking into pleural cavity
(Decrease negative intrapleural pressure, lung recoil inward, chest recoil outward - back to original position)
What is elasticity? What is copliance?
Elasticity:
Compliance: Change in volume that occurs per unit change in the pressure of the system ( V / P) - how much something can stretch
Determinants of elasticity of lung
- Presence of elastin
- Surface Tension - surfactant!
Determinants of elasticity of chest-wall
Factors affecting lung compliance
Factors affecting chest-wall compliance
What is the function of surfactant? Are there any consequences of its defiency?
Surfactant: Protein-carbohydrate-phospholipid complex, produced by Type II Cells
Function: Decrease surface tension
Deficiency: Stiff lung,
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