Structure and Function of Lungs PDF

Lungs Introduction to the structure and function of the lungs and position in the thorax Dr Mona Arafa ([email protected])  Learning outcomes a. Describe the position of the lungs in the thorax b. Name and identify the components of the lungs and bronchial tree (excl...

Lungs Introduction to the structure and function of the lungs and position in the thorax Dr Mona Arafa ([email protected])  Learning outcomes a. Describe the position of the lungs in the thorax b. Name and identify the components of the lungs and bronchial tree (excluding bronchiopulmonary segments) c. Describe the organisation and function of the pleura d. Explain the structure and importance of the lymphatic system in the thorax  Clinical scenario A 2 ½ year old returns to the A&E for a sore throat. According to the mom, the doctor did nothing during their previous visit (24hrs before) but had just sent the baby home with antibiotics for pharyngitis. Mom is not happy and is worried because her daughter doesn’t want to eat. She will drink fluids, but winces each time she swallows. When asked what’s wrong, the daughter grabs her throat and tells you: “It hurts.” When her mom makes her eat, she vomits up the food.  Clinical scenario A 2 ½ year old returns to the A&E for a sore throat. According to the mom, the doctor did nothing during their previous visit (24hrs before) but had just sent the baby home with antibiotics for pharyngitis. Mom is not happy and is worried because her daughter doesn’t want to eat. She will drink fluids, but winces each time she swallows. When asked what’s wrong, the daughter grabs her throat and tells you: “It hurts.” When her mom makes her eat, she vomits up the food.  Ribs 12 pairs of bones that form the thoracic skeleton Typical and atypical (based on structure) True, false and floating (relationship to the sternum)  Pleura The layers around the wrist represents the visceral layer while the layer distal from the wrist depicts the outer parietal layer.  Pleura and lungs – surface anatomy Red line (pleura): 1 inch : above the mid point of medial 1/3 of clavicle 2nd rib: pleura from both the sides meet in the mid line 4th rib: the left side pleura deviate from midline to accommodate the heart 6th rib: the right sided pleura continue parasternally to 6th rib 8th rib: both pleura diverge and cross the mid- clavicular line 10th rib: both pleura diverge and cross the mid- axillary line 12th rib: both reach the posterior chest just below 12th rib Blue line (lungs): Lungs are always two rib spaces above/less than pleura Lungs Lungs  Structure of the lungs Identify: 1 1 1. Apex 2. Base 3. Oblique fissure 4. Transverse fissure 4 3 3 2  Hilum What is hilum?  Hilum A B Left Right R- Right B- Bronchus S- Superior Hilum R- Right B- Bronchus S- Superior Recovery position  Recovery position Right principal Left principal bronchus is wider bronchus is and more vertical narrower and more angular R L Chest X-Ray  Chest X-Ray PA view AP view  PA chest X-Ray PA View Postero-Anterior view A A- Arch of aorta / /aortic knuckle B B- Pul artery G C- LA D- RV H C E- Apex beat F- Fundal gas shadow G- SVC I D H- Broncho pulmonary vasculature E I- RA J- Costo-phrenic angle J F What’s wrong?  Lymphatic system A 65-year-old woman presents with a palpable lump in her left breast. On examination, the lump is 3cms in diameter. Her axillary lymph nodes are palpable. What might be happening here? Investigations? Mammogram of left breast showing the lesion Why axillary lymph nodes are palpable?  Lymphatic system System that is complimentary to circulatory system that removes excess fluid from the body and returns it to the bloodstream source (1) Blood pressure forces plasma out of the arteriole end of the capillaries and into the interstitial fluid between the cells of the tissue (2) Of the 20L per day that's forced through the arteriolar end of all the capillaries all over the body, only 17L is taken back up by the venous end the remaining 3L becomes lymph (3) They almost immediately get absorbed into lymphatic vessels to be taken back  Lymphatic system Consists of: Lymphatic fluid – consists of lymphocytes Lymphatic vessels - carry lymph away from the tissues to deliver it back into the blood's circulation Lymph nodes- filtering interstitial fluid collected from soft tissues and eventually returning it to the vascular system Lymphatic ducts – Lymphatic ducts empty lymph fluid into the venous system. The two lymphatic ducts of the body are the right lymphatic duct and the thoracic duct. Lymphatic organs Primary Secondary Bone marrow, Thymus Spleen Produce lymphocytes Maturation of lymphocytes to fight infection Initiate acquired immune response (immunological memory)  Lymphatic system Lymphatic ducts – Lymphatic ducts empty lymph fluid into the venous system. The two lymphatic ducts of the body are the right lymphatic duct and the thoracic duct. Spot the difference Spot the difference We would like to thank Cardiff University and the medical staff for the initial creation of these teaching resources.