1. Bronchopulmonary segment Anatomy

2. Respiratory system Consists of two parts Upper respiratory system Nose Pharynx Associated structures Paranasal air sinuses Lower respiratory system Larynx Trachea Bronchi Lungs

3. Nose Nose is divided into two regions External nose Internal nasal cavity

4. Paranasal Sinuses Surround the nasal cavity Lighten the skull Help to warm and moisten the inspired air

5. Pharynx Funnel-shaped tube of skeletal muscle Common passage to Air & food Connects to Nasal cavity and mouth superiorly Larynx and esophagus inferiorly Extends From base of skull To level of sixth cervical vertebra

6. Larynx (Voice Box) A role in speech (voice production) Acts as an airway Nine cartilages involved in its formation

7. Trachea Wind pipe Formed of cartilage and fibromuscular membrane Lined internally by mucosa Made up of incomplete rings of cartilage C shaped cartilages 10 - 11 cm Extent From the level of sixth cervical vertebra To the upper border of the fifth thoracic vertebra

8. Lungs Paired organs Occupy Most of thoracic cavity Apex Narrow, superior portion Lies near clavicle Base Broad part Rests on diaphragm (inferior portion) The bronchi enters the lung at the hilus (medial depression)

9. Lungs Each lung is divided into Lobes by fissures Left Lung Two lobes By an oblique fissure Right Lung Three lobes By Oblique & horizontal fissures

10. Respiratory Tree Bronchial or respiratory tree Branching and rebranching of Bronchus within the lungs Parts of bronchial tree are Primary bronchi Secondary bronchi Tertiary bronchi Bronchioles Terminal bronchioles

11. Principal Bronchi Right Wider, shorter & more vertical Before entering the lung Gives superior lobar bronchus On entering the lung Divides into Middle lobar bronchus Inferior lobar bronchus Left Narrower, longer & more horizontal On entering the lung Divides into Superior lobar bronchus Inferior lobar bronchus

14. Secondary (lobar) bronchi Within lung primary bronchi branch into secondary (lobar) bronchi 3 in right lung 2 in left lung

15. Tertiary bronchus Lobar bronchi (also called secondary bronchi) divide into tertiary bronchi Each tertiary bronchus supplies air to a portion of lung tissue that is known as bronchopulmonary segment

16. Bronchopulmonary segments Anatomical, functional and surgical units of lungs Each lobar (secondary) bronchus gives off branches called segmental (tertiary) bronchi Each segmental bronchus passes to a structurally and functionally independent unit of a lung lobe called a bronchopulmonary segment, surrounded by connective tissue

17. Bronchopulmonary Segment - Characters Subdivision of a lung lobe Pyramid shaped Apex toward the lung root Surrounded by connective tissue Contains Has separate segmental artery, segmental (tertiary) bronchus, lymph vessels & autonomic nerves Segmental vein lies in connective tissue between adjacent bronchopulmonary segments Diseased segment can be removed surgically without affecting the function of other segments There are 10 bronchopulmonary segments in each lung

18. Bronchopulmonary segments – Right lung Superior Lobe Apical Anterior Posterior Middle Lobe Medial Lateral Inferior lobe Anterior basal Medial basal Lateral basal Posterior basal Superior basal

19. Bronchopulmonary segments – Left lung Superior lobe Apical Anterior Posterior Linguala part Superior lingular Inferior lingular Inferior lobe Superior basal Anterior basal Medial basal Lateral basal Posterior basal

20. Clinical significance Spreading of infection form one segment to other segment is prevented by connective tissue Except tuberculosis Apical segment of lower lobe and posterior segment of upper lobe are common sites of abscess Most dependent segments in supine position

21. Smooth muscle Lamina propria Epithelium Transitional part between conducting & respiratory parts No difference with terminal bronchiole Only wall is interrupted by alveoli Bronchiole Smooth muscle Epithelium Alveolus Respiratory bronchiole

22. Alveolar duct From respiratory bronchiole Lined by squamous epithelium Supported by smooth muscle Open into atria

23. Alveolus Parenchyma of lung Exchange of gases between air & blood Honeycomb appearance In between alveoli present inter alveolar septum Alveolus is lined by Type 1 Pneumocytes/ Type 2 Pneumocytes Type 2 Pneumocytes produce pulmonary surfactant Smooth muscle Epithelium Alveolus