Lungs Notes PDF

**[LUNGS]** -the lung is divided into 2 main zones 1\. conducting zone- tubes that move air into the lungs and don't have gas exchange abilities- generations 16 2\. transitional and respiratory zone-tubes with alveoli on the sides and then go into alveolar ducts and then sacs- generation 17 down...

**[LUNGS]** -the lung is divided into 2 main zones 1\. conducting zone- tubes that move air into the lungs and don't have gas exchange abilities- generations 16 2\. transitional and respiratory zone-tubes with alveoli on the sides and then go into alveolar ducts and then sacs- generation 17 down you will get gas exchange -apex of the lung- rises above the clavicle- cupula of the lung- important in putting in central lines into the internal jugular vessels. -Misdirection of the needle can puncture the apex of the lung -Costodiaphragmatic recess of plural cavity- the pleural space is below lungs. Can collect 500cc of pleural fluid before you see it on a chest x-ray -aspiration go into the lower lobes -phrenic nerve c3-c5 -7^th^ rib connected to the sternum helps with mobility in the chest wall -hoarseness can be a sign of lung cancer -pulmonary artery carries deoxygenated blood from right side of heart to the lungs **[LUNG CIRCULATION]** 1\. pulmonary artery- come from right side of heart 2\. Bronchiole artery- come off the aorta and run along the large tubular structures and help to supply them (trachea and bronchi) -if you have a PE and block pulmonary arteries you can infarct the lungs - Young people, Bronchiole artery can help protect from pulmonary infarct -pulmonary infarct is not common in age below 40 -when there is lung scarring caused by TB, dilatation of arteries in the chest can cause hemoptysis (coughing up blood) -blood flow in bronchiole arteries are under systemic pressure- bleeding is usually coming from the bronchiole artery **[LYMPH VESSELS AND NODES OF THE LUNG ]** -lymph drainage from the right arm and head come into the bronchomediastinal vessel right side -Lymph flow from the rest of the body flows through the thoracic duct -Once you start to see alveoli budding off the bronchi- now called respiratory bronchiole -pores of kohns- protect us by matching ventilation and perfusion Downside of this is- if you get pneumonia, bacteria can spread **[INSPIRATION VS EXPIRATION]** -inspiration is active Stores energy in the elastic tissues Diaphragm and external intercostal muscles -expiration is passive -forced expiration maybe from exercise Internal intercostal muscles and abdominal muscle Internal intercostal muscles on the chondral part of the ribs are inspiration But internal intercostal muscles on the bony parts are forced expiration **[MEDULLA]** -the medulla houses neurons that generate signals to cause breathing -fire repetitively to cause to breathe **[RECEPTORS]** -have feedback (mechanoreceptor) come from the muscles to the brainstem and spinal cord -chemoreceptor feedback that respond to oxygen and carbon dioxide in the brainstem and carotid bodies -peripheral receptors: detect irritants or vascular congestion Vascular congestion: pulmonary edema- developing it can result in o2 stat at 96 but tachypnic and SOB -higher centers in the brain can impact the resp neurons in the medulla telling resp system to breathe \--belching, swallowing and vomiting are relayed through the brain stem When vomiting youre not breathing so it needs to be organized through the CNS -cranial nerves involved- glossalpharyngeal-carries information from carotid bodies containing receptors that feedback to resp system trigeminal- afferent stimuli from nasal cavity and oral cavity which can affect the breathing **Hering-Breuer reflex-** helps avoid overinflation of the lungs **-mucociliary escalator:** protect the lung against large particles **-tight junctions:** prevent invasion **-lysozyme, defensins, and antimicrobial peptides:** deter pathogens **-mucosal dendritic cells**: ingest particles and digest and present antigens from them to lymphocytes causing production of IgA. **-IgA:** in our secretions that helps tag pathogens for phagocytosis in destruction **-IgG:** neutralized small particles and have macrophages and phagocytose (destroys) them **-macrophages:** cytokines recruit monocytes, neutrophils, and lymphocytes to assist. **-natural killer cells:** in the alveoli and contribute to rapid response to invading pathogens **-protective antimicrobial proteins:** components of surfactant that lines the alveoli **[CYSTIC FIBROSIS]** -autosomal recessive genetic disorder -cannot secrete chloride across epithelial cells membrane and water follows movement of chloride -you end up with mucus lining the airway extremely viscous and cilia are not able to function in the mucociliary escalator -cannot secrete bicarb which makes the mucus acidic reducing the effectiveness of white blood cells that help attack pathogens -the sodium transporter causes water to follow into the cell causing thickness in secretions -CF patients tend to develop lung infections from the inability to clear mucus from their lungs and can form airway dilation and cause scarring in the tubes called bronchiectasis. **[LUNG VOLUME AND CAPACITY MEASUREMENTS ]** **Tidal volume:** volume of air that moves when normal quiet breathing in and out **Functional residual capacity:** the volume of air in the lungs at the end of each expiration at rest **Vital capacity:** the maximum amount of air that can be inhaled and exhaled **Residual volume:** amount of air left after a maximum expiratory effort **Total lung capacity:** total amount of air in the lungs after maximal inhalation **[LUNG AND CHEST WALL RELATIONSHIPS]** -lung are suspended inside the chest wall and they have a tendency to want to retract. -lungs have elastic recoil -chest wall is designed to spring outward -pneumothorax can occur in two ways 1\. hole inside chest wall that lets air inside 2\. hold inside lung where air can escape into the pleural cavity -one side starts to bow out. -we want mechanical coupling for normal lung functioning between the lung and chest wall **[PLEURAL EFFUSION-fluid in the pleural space]** -caused by imbalance of fluid production and filtration out of pleural space -transudative effusions: associated with fluid overload like HF, cirrhosis, ESRD -exudative effusions: (more worrisome) damage to the lungs like inflammation like pneumonia or malignancy **[PH OF PARAPNEUMONIC EFFUSIONS]** 1. Complicated: viscous and invaded by bacteria that caused the pneumonia-can progress into empyema (pus in pleural space) 2. Uncomplicated: free flowing and not contaminated by bacteria - send fluid for ph analysis -if ph is \>7.3, it is uncomplicated -If ph is \15min, systolic BP \