Primary function of respiratory system

Transport oxygen from air to blood and carbon dioxide from blood to air

Upper respiratory tract

Includes nasal cavity pharynx and larynx warms moistens and filters air

Lower respiratory tract

Includes trachea bronchi bronchioles and alveoli and is the main site of gas exchange

Alveoli

Thin walled air sacs lined with simple squamous epithelium and surfactant where gas exchange occurs

Surfactant

Substance reducing surface tension to keep alveoli inflated

Ventilation

Movement of air into and out of lungs driven by pressure gradients

Boyles law in breathing

Air moves from high pressure to low pressure during inspiration and expiration

Tidal volume

Amount of air exchanged in normal breathing

Vital capacity

Maximum air that can be inhaled and exhaled with forced breathing

Residual volume

Air remaining in lungs after maximum expiration

Central chemoreceptors

Located in medulla detect CO2 and pH changes

Peripheral chemoreceptors

Located in carotid bodies detect oxygen carbon dioxide and pH changes

Hypercapnia

Increased carbon dioxide causing respiratory acidosis and increased respirations

Hypocapnia

Low carbon dioxide usually from hyperventilation causing respiratory alkalosis

Hypoxemia

Low oxygen level in blood stimulating respiratory drive

Gas exchange mechanism

Gases diffuse across respiratory membrane based on partial pressure gradients

Ventilation perfusion ratio

Matching of airflow and blood flow required for efficient gas exchange

Spirometry

Pulmonary function test measuring lung volumes and airflow

Arterial blood gas test

Measures oxygen carbon dioxide bicarbonate and blood pH

Pulse oximetry

Measures oxygen saturation in blood

Bronchoscopy

Visual examination of airways allowing biopsy and identification of bleeding or lesions

Sputum culture

Identifies respiratory pathogens and antibiotic sensitivity

General respiratory disease manifestation cough

Protective reflex removing irritants from airways

Dyspnea

Subjective sensation of difficult or uncomfortable breathing

Cyanosis

Bluish discoloration due to increased deoxygenated hemoglobin

Rales

Crackling breath sounds from fluid in alveoli

Rhonchi

Low harsh sounds caused by thick mucus in airways

Stridor

High pitched sound indicating upper airway obstruction

Hemoptysis

Coughing up blood tinged sputum

Common cold cause

Viral infection transmitted by respiratory droplets

Common cold treatment

Supportive care antivirals and prevention through hygiene

Sinusitis cause

Usually bacterial infection of sinus cavities

Sinusitis treatment

Analgesics and antibiotics if bacterial

Epiglottitis cause

Bacterial infection causing swelling of epiglottis and airway obstruction risk

Epiglottitis key signs

Drooling difficulty swallowing anxiety tripod position

Epiglottitis treatment

Oxygen therapy and antimicrobial drugs

Influenza cause

Highly contagious viral infection with frequent mutation

Influenza manifestations

Sudden fever fatigue body aches cough and possible viral pneumonia

Influenza prevention

Vaccination respiratory hygiene antiviral medications

Bronchiolitis cause

Respiratory syncytial virus infection of small bronchi and bronchioles

Bronchiolitis manifestations

Wheezing dyspnea rapid shallow breathing fever cough

Pneumonia definition

Inflammation of lung tissue with exudate in alveoli impairing gas exchange

Lobar pneumonia cause

Usually Streptococcus pneumoniae producing consolidation in one lobe

Lobar pneumonia sputum

Rust colored sputum due to alveolar exudate

Bronchopneumonia pattern

Diffuse infection in multiple lung areas with purulent sputum

Atypical pneumonia cause

Often Mycoplasma or viral organisms producing milder symptoms

Tuberculosis cause

Mycobacterium tuberculosis transmitted by respiratory droplets

Primary TB

Initial infection often asymptomatic with granuloma formation

Active TB manifestations

Weight loss fever night sweats prolonged productive cough blood sputum

TB diagnosis

Tuberculin skin test sputum culture chest radiograph

TB treatment

Long term combination antibiotic therapy

Cystic fibrosis cause

Genetic disorder producing thick tenacious mucus in lungs pancreas and ducts

Cystic fibrosis lung effect

Mucus obstructs bronchi leading to infections and airflow limitation

Cystic fibrosis diagnosis

Sweat test genetic testing pulmonary tests

Cystic fibrosis treatment

Chest physiotherapy nutritional therapy infection control

Lung cancer major risk

Smoking accounts for about 90 percent of cases

Lung cancer early sign

Persistent cough hemoptysis chest pain

Lung cancer diagnosis

CT scan radiography bronchoscopy biopsy

Lung cancer treatment

Surgery chemotherapy radiation or ablation

Asthma definition

Chronic inflammatory airway disease with hyperresponsive bronchi and reversible obstruction

Extrinsic asthma

Triggered by allergic hypersensitivity reactions

Intrinsic asthma

Triggered by infections stress cold exercise or irritants

Asthma pathophysiology

Bronchoconstriction mucosal edema and thick mucus obstruct airways

Asthma manifestations

Wheezing dyspnea chest tightness tachycardia hypoxia

Status asthmaticus

Severe prolonged asthma attack not responding to treatment and potentially fatal

Asthma treatment

Bronchodilators glucocorticoids avoidance of triggers maintenance inhalers

COPD definition

Group of chronic progressive lung diseases causing irreversible airflow limitation

Emphysema pathophysiology

Destruction of alveolar walls reducing surface area and causing air trapping

Emphysema hallmark

Barrel chest from hyperinflated lungs and flattened diaphragm

Emphysema manifestations

Progressive dyspnea weight loss fatigue prolonged expiration

Chronic bronchitis definition

Productive cough for at least 3 months in 2 consecutive years

Chronic bronchitis pathophysiology

Inflamed thickened bronchi with mucus gland enlargement and fibrosis

Chronic bronchitis manifestations

Chronic productive cough cyanosis dyspnea thick secretions

COPD treatment

Smoking cessation bronchodilators vaccines oxygen therapy rehabilitation

Pulmonary edema

Fluid accumulation in alveoli reducing oxygen diffusion and lung expansion

Pulmonary edema signs

Cough orthopnea frothy sputum hypoxemia cyanosis

Pulmonary embolus

Obstruction of pulmonary artery usually from deep vein thrombosis

Pulmonary embolus signs

Sudden dyspnea chest pain tachycardia anxiety hypoxia

Pulmonary embolus prevention

Anticoagulants early ambulation compression stockings

Infant respiratory distress syndrome

Caused by surfactant deficiency in premature infants leading to alveolar collapse

Infant RDS signs

Rapid shallow breathing cyanosis frothy sputum decreased breath sounds

Infant RDS treatment

Synthetic surfactant oxygen CPAP ventilation support

Adult respiratory distress syndrome

Acute inflammatory lung injury causing fluid leakage surfactant damage and severe hypoxia

ARDS manifestations

Rapid shallow breathing dyspnea tachycardia respiratory and metabolic acidosis

ARDS treatment

Supportive ventilation and treatment of underlying cause

Acute respiratory failure

Inability of lungs to maintain adequate oxygenation or carbon dioxide removal

Respiratory failure treatment

Treat underlying disorder and provide respiratory support