The Respiratory System
Respiratory Anatomy • Upper respiratory tract – Nose – Nasal passages – Pharynx – Larynx
Respiratory Anatomy • Functions of the upper respiratory tract: – Provide entry for inhaled air
Respiratory Anatomy • Functions – Nasal mucosa • Traps bacteria & foreign particles • Warms & moistens incoming air • Part of natural immunity
Respiratory Anatomy • Pharynx • Part of the digestive and respiratory systems • Allows for passage of both air and food • Mucosa of pharynx is part of immune system, source of antibodies & protective substances
Respiratory Anatomy • Larynx – Lined with squamous epithelium and enclosed in cartilage for support and protection – Organ of speech – Improperly functioning larynx can lead to aspiration of food or liquid into lungs
Lower Respiratory Tract • Trachea • Bronchii • Bronchioles • Terminal alveoli in lungs
Respiratory Anatomy • Trachea • Leads to the L & R bronchi • Lined with: – Ciliated cells – Mucus producing cells – Neuroendocrine cells – Basal cells • With chronic smoking basal cells change-> basal squamous metaplasia Lung CA
Respiratory Anatomy • L and R bronchi enter the L and R lungs – Branch many times, becoming narrower into bronchioles then avleolar ducts and alveolar sacs (alveoli) • Alveoli – Lined with pneumocytes • Thin cells that allow for gaseous exhange • Cells that produce a pulmonary surfactant that coats the alveoli and keeps them from collapsing.
Respiratory Anatomy • Pulmonary lobules – many lobules make up the pulmonary lobes • 3 on the Right and 2 on the Left
Pulmonary Blood Supply • Dual blood supply – Pulmonary artery • Brings de-oxygenated (venous) blood from the R ventricle into the lungs • Blood is oxygenated in lungs – Pulmonary vein • Brings oxygenated blood from lungs into L atrium
Respiratory Anatomy • Outer surface of lungs= pleura – Moist surface – Filters air, keeps air moist, and retains large particles and bacteria. – Provides protection against infection
Function of Lungs • Major function of the lungs: – Respiration • Metabolic function of the lungs: – Maintain acid-base balance • Prevention of acidosis or alkalosis – Affects the kidneys, gastrointestinal tract
Important Terminology • Dyspnea- SOB • Cyanosis- bluish color of eh skin and mucous membranes • Clubbing- thickening and widening of terminal phalanges of fingers and toes • Hypoxia- diminished availability of O2 to body tissues • Normal resting rate of ventilation: 12-20 breaths per minute
Signs and Symptoms of Pulmonary Disease • Cough • Dyspnea • Cyanosis • Chest pain • Abnormal chest shape • Abnormal sputum
Respiratory Diseases • Major Diseases – Infectious – Immune – Environmentally Induced – Circulatory – Neoplastic (Tumors)
Infectious Diseases • Upper Respiratory Infections (URI) – Etiology & Pathogenesis • viral • short lived • heal spontaneously • Acute inflammation of the nose, paranasal sinuses, throat, or larynx
Infectious Disease • Clinical Findings – Nasal congestion – General malaise – Mild fever – Rhinorrheah (runny nose)
Infectious Disease • Middle Respiratory System – More prevalent among children – croup • Barking cough due to spasm of vocal cords – Whooping cough
Infectious Diseases • Pneumonia – Inflammation of the lung • Bacterial infection (75%) or viral infection • Less frequently by fungi, protozoa or parasites • Inhalation of smoke, dust, gases • Aspiration of food or liquid
Infectious Diseases • Pneumonia – Clinical manifestations: • Pleuritic chest pain • Fever • Hacking, productive cough – Blood tinged sputum • SOB • Fever • Generalized fatigue
Infectious Diseases • Tuberculosis (TB) – Chronic bacterial infection • Localized lung infection • Inhalation of infected airborne particles • Remains clinically unrecognized in 95% of the cases – Ultimately impair lung function and potentially other organs as well
Tuberculosis • Symptoms: – Productive cough – General body symptoms • Diagnosis – Chest x-ray – Skin test
Chronic Obstructive Pulmonary Disease (COPD) • Lung diseases with chronic airway obstruction • Includes: – Chronic bronchitis – Emphysema
Emphysema • Enlargement of the airspaces distal to the terminal bronchioles • Destruction of the alveolar walls • Obstruction results from changes in lung tissues • Loss of elasticity in lung tissue narrows or collapses bronchioles
Emphysema • Clinical manifestations: – Dyspnea – Cough is uncommon – Barrel chest – Anxiety
Chronic Bronchitis • Productive cough lasting at least 3 months for 2 years • Inflammation and scaring of bronchial lining • Increases mucus production
Chronic Bronchitis • Clinical manifestations: – Persistent, productive cough – SOB – Recurrent infections
COPD • Two prototypic groups – Predominant bronchitis- “blue bloaters” • Prolonged coughing, dyspnea, cyanosis – Predominant emphysema- “pink puffers” • Chest is over-expanded or barrel chested, hyper-ventillation, over-inflation with a small heart
Immune Diseases • Allergic Rhinitis – Hay fever • Type I hypersensitivity reaction affecting the nasal mucosa to exogenous allergens • Acute vasomotor response mediated by histamine and related vasoactive substances
Asthma • Acute, reversible, inflammatory, obstructive lung disease • Inflammation of bronchia mucosa, increased permeability of blood vessels in bronchi, and contraction and spasm of smooth muscle in bronchi • Two major forms: – Extrinsic (allergic) – Intrinsic (non allergic)
Asthma • Signs & Symptoms – Wheezing – Dyspnea – Cough – Goal is to reduce exposure to the irritant that induces the bronchospasm
Silicosis & Asbestosis • Diseases caused by the inhalation of substances • Causes various types of lung diseases • Symptoms • Pulmonary fibrosis • Pleural fibrosis & pleural plaques • Lung cancer
Adult Respiratory Distress Syndromes (ARDS) • Severe impairment in oxygenation of blood • Mechanism of lung injury varies depending on cause: – Shock • Trauma • Burns • Acute cardiac failure – Pneumonia • Viral or bacterial – Toxic lung injury – Aspiration of fluids • Near drowning
ARDS • Clinical manifestations: – Increased respiratory rate – Pulmonary edema – Atelectasis – Dyspnea – Can progress to MODS (multiple organ dysfunction syndrome) – Severe distress – SOB
ARDS • Prognosis – Mortality rate of 50-70% – Survivors asymptomatic in several months and have normal lung function in 1 yr
Ventilatory Failure • Spinal cord injury • Poliomyelitis • Tetanus • Myesthenia gravis – Affects the neuromuscular junction • Muscular dystrophy (Duchenne) • Cystic fibrosis
Atelactasis • Incomplete expansion or collapse of the alveoli – Deficiency of surfactant – Compression of the lungs from outside – Resorption of air distal to bronchial obstruction
Neoplasms of the Respiratory Tract • Carcinoma of the larynx – Linked to smoking & chronic alcohol intake • Affects males 7x more than females • Lung Carcinoma – Leading cause of cancer death in the USA & most other Western industrialized countries – In most cases, it is caused by smoking • 90% of patients are smokers • 5 year survival rate 10-15%, incurable
Lung Carcinoma • Classified as: – Small cell lung cancer (SCLC) – Non SCLC (NSCLC) • Prognosis: – Curability is poor
Pleural Diseases • Accumulation of fluid in the pleural cavity – Hydrothorax or Pleural effusion • Fluid can be transudate or exudate • Accumulation of air in pleura cavity – pneumothorax
Recommend
More recommend
