The Respiratory System

Transcription

1 The Respiratory System

2 Respiratory Anatomy Upper respiratory tract Nose Nasal passages Pharynx Larynx

3 Respiratory Anatomy Functions of the upper respiratory tract: Provide entry for inhaled air

4 Respiratory Anatomy Functions Nasal mucosa Traps bacteria & foreign particles Warms & moistens incoming air Part of natural immunity

5 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

6 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

7 Lower Respiratory Tract Trachea Bronchii Bronchioles Terminal alveoli in lungs

8 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

9 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.

10 Respiratory Anatomy Pulmonary lobules many lobules make up the pulmonary lobes 3 on the Right and 2 on the Left

11 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

12 Respiratory Anatomy Outer surface of lungs= pleura Moist surface Filters air, keeps air moist, and retains large particles and bacteria. Provides protection against infection

13 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

14 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: breaths per minute

15 Signs and Symptoms of Pulmonary Disease Cough Dyspnea Cyanosis Chest pain Abnormal chest shape Abnormal sputum

16 Respiratory Diseases Major Diseases Infectious Immune Environmentally Induced Circulatory Neoplastic (Tumors)

17 Infectious Diseases Upper Respiratory Infections (URI) Etiology & Pathogenesis viral short lived heal spontaneously Acute inflammation of the nose, paranasal sinuses, throat, or larynx

18 Infectious Disease Clinical Findings Nasal congestion General malaise Mild fever Rhinorrheah (runny nose)

19 Infectious Disease Middle Respiratory System More prevalent among children croup Barking cough due to spasm of vocal cords Whooping cough

20 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

21 Infectious Diseases Pneumonia Clinical manifestations: Pleuritic chest pain Fever Hacking, productive cough Blood tinged sputum SOB Fever Generalized fatigue

22 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

23 Tuberculosis Symptoms: Productive cough General body symptoms Diagnosis Chest x-ray Skin test

24 Chronic Obstructive Pulmonary Disease (COPD) Lung diseases with chronic airway obstruction Includes: Chronic bronchitis Emphysema

25 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

26 Emphysema Clinical manifestations: Dyspnea Cough is uncommon Barrel chest Anxiety

27 Chronic Bronchitis Productive cough lasting at least 3 months for 2 years Inflammation and scaring of bronchial lining Increases mucus production

28 Chronic Bronchitis Clinical manifestations: Persistent, productive cough SOB Recurrent infections

29 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

30 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

31 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)

32 Asthma Signs & Symptoms Wheezing Dyspnea Cough Goal is to reduce exposure to the irritant that induces the bronchospasm

33 Silicosis & Asbestosis Diseases caused by the inhalation of substances Causes various types of lung diseases Symptoms Pulmonary fibrosis Pleural fibrosis & pleural plaques Lung cancer

34 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

35 ARDS Clinical manifestations: Increased respiratory rate Pulmonary edema Atelectasis Dyspnea Can progress to MODS (multiple organ dysfunction syndrome) Severe distress SOB

36 ARDS Prognosis Mortality rate of 50-70% Survivors asymptomatic in several months and have normal lung function in 1 yr

37 Ventilatory Failure Spinal cord injury Poliomyelitis Tetanus Myesthenia gravis Affects the neuromuscular junction Muscular dystrophy (Duchenne) Cystic fibrosis

38 Atelactasis Incomplete expansion or collapse of the alveoli Deficiency of surfactant Compression of the lungs from outside Resorption of air distal to bronchial obstruction

39 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

40 Lung Carcinoma Classified as: Small cell lung cancer (SCLC) Non SCLC (NSCLC) Prognosis: Curability is poor

41 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