Gross anatomy of lungs

INTRODUCTION: Lungs are a pair of respiratory organs
2. lungs function and landmarks
3. related diseases
4. arterial and venous supply
5. Fissures and lobes

1. Anatomy Submitted to : Dr. Tayyaba Aslam Submitted by : Sumayya Farooq Roll No : 045

2. GROSS ANATOMY of Lungs

3. Function: To extract oxygen from the atmosphere Transfer it into the bloodstream To release carbon dioxide from the blood stream into the atmosphere, in a process of gas exchange. Respiration is driven by different muscular systems in different species.

4. Structure of the Lungs: The lungs are the organ for respiration. They are paired cone shaped organs lying in the thoracic cavity. They are separated from each other by the heart. And other structures in the mediastinum.

5. Division: Humans have two lungs, a right lung, and a left lung. The right lung is shorter and wider than the left lung. The left lung occupies a smaller volume than the right. The Each lung has a base resting on the diaphragm An apex extending superiorly to a point approximately 2.5cm superior to the clavicle

6. Apex: Blunt Lies above the level of anterior end of 1 st Rib. Reaches 1-2 cm above medial 1/3 rd of clavicle. Covered by cervical pleura and supra pleural membrane. Grooved by subclavian artery and subclavian vein.

7. Base: Semilunar and concave. Rests on dome of Diaphragm. Right side dome is higher than left

8. Pleura: Each lung is invested by and enclosed in a serous pleural sac that consists of two continuous membranes. The inner layer (visceral pleura) wraps around the lungs It is stuck so tightly to the lungs that it cannot be peeled off. The outer layer (parietal pleura) lines the inside of the chest wall.

9. Pleural Cavity: The pleural cavity also known as pleural space. It is the thin fluid-filled space between the two pulmonary pleura of each lung.

10. Fissures and Lobes of Lungs: Each lung is composed of smaller units called lobes. Fissures separate these lobes from each other. The right lung consists of three lobes: the superior, middle, and inferior lobes. The left lung consists of two lobes: the superior and inferior lobes.

11. Oblique Fissure: It begins posteriorly at the level of 5 th thoracic vertebrae. Passes antero-inferiorly in a spiral course to meet the inferior margin close to 6 th costochondral junction.

12. Horizontal fissure: It extends from anterior margin at the level of 4 th costal cartilage. Runs horizontally backwards to meet the oblique fissure in the mid-axillary line. Pulmonary pleura extends into the fissures of the lungs so that the lobes can move on each other during respiration.

13. Hilum: It is a large depressed area that lies near the center of the medial surface. Various structure enter and leave the lung via its root.

14. Cardiac Notch: The CARDIAC NOTCH is an indentation on the surface of the left lung It allows space for the heart.

15. Bronchopulmonary segments: These are well defined areas of the lungs, each of which is aerated by a segmental/ tertiary bronchus.

16. Trachea Right and Left Principal Bronchus Lobar bronchi(Secondary) Segmental Bronchi(tertiary) Terminal Bronchioles(25000 in no.) Respiratory Bronchioles Alveolar Ducts Alveolar Sacs Alveoli

17. Bronchopulmonary Segments Right main bronchus Shorter Wider. More in line with trachea. Left main bronchus Longer Narrower. More oblique than right .

18. Arterial and Venous Supply:

19. Bronchial Veins: The bronchial veins are small vessels. They return blood from the larger bronchi and structures at the root of the lungs. The right side drains into the azygous vein, While the left side drains into the left superior intercostal vein or the accessory hemiazygos vein. Bronchial veins are thereby part of the bronchial circulation, Carrying waste products away from the cells that constitute the lungs.

20. Bronchial Artery: In human anatomy , the bronchial arteries supply the lungs with nutrition and oxygenated blood. Although there is much variation , there are two bronchial arteries That run to the left lung , and one to the right lung. The bronchial arteries are counterparts to the bronchial veins.