Respiratory Pathology Flashcards
Why are respiratory tract infections so common in children?
Poor sanitary habits, low defences
How would you explain the management of antibiotics for URTI?
Antibiotics only work for bacterial infection not viral, so eating it without reason creates resistance of the pathogen to the medicine.
what are the common pathogens for influenza
Type A, B and C
Compare the clinical features for common cold an influenza
- Cold Onset Gradual Fever rare headache rare malaise mild a runny nose yes cough productive chill rare
- Influenza Onset Abrupt Fever common headcahe severe malaise yes runny nose sometimes cough dry chill common
How does seasonal influenza infect the respiratory tract
Virus binds and enters respiratory epithilium
makes the host cells replicate the virus
leads to necrosis of respiratory tract
why is influenza a problem over other URTI?
It may spread to lower respiratory tract and create necrosis in the lungs. may lead to death
What is croup, clinical presentation, mechanism and management and progression?
Acute laryngotracheobronchitis,
Clinical - cold, fever, hoarseness, cyanosis, night barking
Pathogens - influenza, parainfluenza, respiratory sycytial virus
Mechanism - invade and destroy epithelial cell, acute inflammation trachea, reduce lumen airway, hypoxia
what is pneumonia and what are the different pathogens that cause it?
Inflammation of lung tissue.
Typical
- Streptococcus
- staphylococcus aureus
Atypical
- legionella
- viral pneumonia
- mycoplasm pneumonia
What are the clinical features of pneumonia
Fever pain dry cough headache myalgia tachypnea Tachycardia Haemoptysis
What is tuberculosis and what mechanism is
responsible?
White lung lesion
pathogen: Mycobacterium tuberculosis
transmission by inhalation
What are the possible outcomes for tuberculosis?
lung tissue necrosis and caceus necrosis
What is the difference between Mantoux and Calmette Guerin?
Mantoux: Skin test to observe exposure to tuberculosis
1) has had vaccine
2) Previous exposure to pathogen
3) life virus
4) Negative - indicative for vaccination
Calmette Guerin: Vaccin to stimulate immunity to virus
What are the mechanisms responsible for infective rhinitis (common cold)?
- Rhinovirus
- Adenovirus
- Echovirus
What is the mode of transmission for infective rhinitis?
Secretion in hand
coughing
sneezing
What is the mode of transmission for influenza?
Airbourne
- Talking
- coughing
- sneezing
What is the pathology of infective rhinitis?
UTI Virus enters epithelium inflammation of vassal mucosa Rhinorhea and congestion spread to sinus, nasopharynx, tonsils and ears
What is whooping cough?
Bacterial infection with Bordetella pertussis
pathophys: Invade and paralyze macrophage
What are the 3 stages of whooping cough?
Catarrhal - inflammation, lacrimation, cough
paroxysmal - change in cough
convalescent - cessation of symptoms 4-6 weeks later
What is allergic asthma and its pathophysiology?
Chronic inflammatory disorder of the airways (airflow obstruction)
Exposure to allergen causes inflammatory response
1) inc. vascular permeability
2) Inc. mucus hypersecretion
3) Bronchoconstriction
What are the different types of asthma?
Allergic asthma: Children - Dust mite, pollen, fur, wheat, fish, egg
Infectious asthma: CHildren - Respiratory syncytial virus, Influenza rhinovirus
Exercise-induced: High intensity exercise
Occupational asthma: exposure to allergic mediators, agriculture, pesticide, animal handlers
Drug-induced asthma: Aspirin NSAID beta blockers.
What is chronic bronchitis and its pathophysiology?
chronic productive cough
Mucus hypersecretion
persistent inflammation of bronchioles
replacement of cilial cells with squamous cells
What is emphysema pathophysiology?
Permanent distention of airspace distal to terminal bronchus
Pathophysiology
- destruction of elastin in alveolar wall
- destruction of elastase
- prevent lung from neutralizing effect of elastase
What are the causes of emphysema?
Smoking - bronchioles
Congenital abnormality - Alveolar ducts
Clinical presentation of asthma
wheezing dyspnea chest pain cough tachypnea anxiety
What is the clinical presentation of status asthmatics?
Compensatory posture inc. accessory mm. respiration tachycardia sweating inability to speak
no response to meds
respiratory arrest
spontaneous pneumothorax
air trapping
Asthma complications?
pneumothorax
status asthmatics
rupture of pleb
What are the4 types of medications for asthma?
preventers
relievers
controllers
antibody therapy
What are the causes of chronic bronchitis?
smoking
pollution
what are the cinical features of chronic bronchitis?
Initial - Blue puffer - daily productive cough for < 3/12 for 2yr
- Cyanotic
- Overweight
- pheripheral oedema
- wheezing
- ronchi
Long-term
- pulmonary hypertension
- Rt heart failure
- Acute respiratory failure
- death
what are the cinical features of emphysima?
Pink - permanent enlargement and destruction of airspace
- old
- thin
- quiet chest
- sever dyspnea
What is pneumothorax?
presence of air in pleural cavity
what is the aetiology and pathophysiology of pneumothorax?
Primary spontaneous = young, thin, male, Inc pleural pressure.
Secondary spontaneous = asthma, emphysema, cyst fibrosis
traumatic open = stab wound or
traumatic close = rib fracture
What is the clinical presentation of pneumothorax?
HBP Tachypnea (no O2) Decreased chest movement no breath sound cyanosis tactile fremitus
What are the different types of benign tumours in lungs?
Pulmonary Hamartoma: disorganized cartilage, adipose tissue, smooth mm. entrapped epithelium, asymptomatic
Pulmonary chondroma: cartilage tumour that appears in multiple sites.
What evidence links smoking to bronchogenic carcinoma?
Lung cancer is doses related, the more you smoke the more you are likely to get a tumour.
there are clear carcinogenic mechanism: benzopyrene in smoke is gene 53 tumour protein
smoking leads to cellular change: metaplasia, carcinoma in situ, invasive cancer.
Differentiate between “Non-small cell lung carcinomas” and “small cell lung carcinoma”
Non small cell carcinoma
85% of carcinoma
derived from epithilium
small cell carcinoma = 15% lung cancer
known as oat cell
they secrete substances
What are the clinical features for bronchogenic carcinoma?
Compresion
- Hornes syndrome
- Swelling face
- upper limb neuro
Obstruction
- appearance or change in cough
- Dyspnea
- pericardial effusion
Invasion of blood cells
- productive cough
- blood in cough
What are the mains points of spread and common sites of bronchogenic carcinomas?
Spread = blood, lymph, direct extension
Lung, liver, breast, kidney, bowel, cervix, skin
What is haemothorax?
blood in cartilage clinical pleural cavity
What is a tension pneumothorax?
when chest wound acts as a one-way valve and air gets trapped in pleural increasing pressure, displacement of the mediastinum and compressing lung. - leads to asphyxiation
