Respiratory System

Negative pressure (suction) causes the visceral pleura to remain in contact with the parietal pleura, so that when the chest wall & parietal pleura move, the parietal pleura takes the visceral pleura and lungs with it.

The left upper lobe contains the cardiac notch, where the left ventricle and pericardial sac lodges. The Lingula (which is the embryologic counterpart to the right middle lobe) lies just beneath the cardiac notch.

The beating of the cilia moves mucus lying on the surface of the epithelium of the conducting zone, and any contained dust, up out of the bronchial tree.

[Ref. Junquira}

The trachea is a tube composed of 16 to 20 U-shaped hyaline cartilages and the trachealis muscle. The trachea begins just inferior to the cricoid cartilage (C6 vertebral level) and ends at the sternal angle (T4 vertebral level), where it bifurcates into the right main bronchus and the left main bronchus. At the bifurcation of the trachea, the last tracheal cartilage forms the carina, which can be observed by bronchoscopy as a raised ridge of tissue in the sagittal plane.

*** The trachea has a fibroelastic wall supported by a cartilaginous skeleton formed by C shaped rings made of hyaline cartilage

Reference: Junqueira’s Basic Histology; 14th Edition; Page-370

No explanation added.

Structures piercing the diaphragm: 
1. Greater, lesser, and least splanchnic nerves pass by piercing the crus of diaphragm on the corresponding side
2. Hemiazygos vein pierces the left crus of the diaphragm
3. Left phrenic nerve pierces left cupola

Bronchodilation is stimulated by sympathetic nerve impulses, adrenalin & noradrenalin. Bronchoconstriction triggered by parasympathetic nerve impulses.

♣ Rima glottidis: The space between two vocal folds is called 'rima glottidis'. It is the narrowest part of the larynx.
♣ Rima vestibuli: The spce between two vestibular folds (false vocal cords) is called rima vestibuli.
♣ Sinus/vestibule of larynx: It is the space between the vocal fold and vestibular folds. 

Reference: Junqueira’s Basic Histology; 14th Edition; Page-370

Reference: Junqueira’s Basic Histology; 14th Edition; Page-370

 Aspiration of any fluid from the pleural cavity is called paracentesis thoracis
 It is usually done in the eighth intercostal space in the midaxillary line
 The needle is passed through the lower part of the space to avoid injury to the principal neurovascular bundle, i e vein, artery and nerve

Pulmonary surfeactant is secreted by type-II alveolar cells (Type-II pneumocytes)
Critical components of the surfactant layer include the phospholipid dipalmitoylphosphatidylcholine (DPPC), cholesterol, and four surfactant proteins.