Respiratory Physiology, Pathology and Lung Volumes Flashcards
What causes inhaled particles to trap in the mucas lining the mucosa?
Turbulence in URT and large surface
Where are small particles trapped?
by mucus further down the branching respiratory tract
What helps clear any particles that could reach alveoli?
Macrophages
What has implications for drug delivery?
Filtration
What does cilia of mucosa do?
Beat in rhythmic and coordinated way and carry trapped particles to pharynx and digestive tract
What happens to swallowed particles in the digestive tract?
broken down by a combo of low PH in the stomach and pepsin
What are tonsils and adenoids rich in? what does it do?
Lymphatic tissue - fixed and wondering macrophages ingest particles and function as APC activating immune system
What are signs of respiratory disease?
Cough, sneeze, dyspnoea, Cyanosis
What does a cough do?
Reflex response to clear congestion in lower RI tract - common sign of respiratory disorder
What does a cough involve?
Inspiration - closure of epiglottis and vocal chords, forceful contraction of abdominal muscles, opening of glottis and vocal chords, expulsion of air under pressure
What km/h can air be expelled?
75-100 and caused by irritation of lower RI tract
What is Dyspnoea?
Difficult or laboured breathing, shortness of breath, result from airway obstruction, caused by reduced lung compliance
What is Cyanosis?
Blueness of skin associated with low blood PO2 in capillary beds
What is most peripheral cyanosis caused by?
Peripheral vasoconstriction seen as response to extreme cold
What can cyanosis be caused by?
Respiratory disorders resulting in blood supply exceeding ventilation rate increased conc of reduced haemoglobin - evident when deoxygenated haemoglobin rises to 5g in arterial blood
What are respiratory disease classified by?
Tissue or organ involved can be;
Infections - due to pathogens
Obstructive lung disease - narrowing of air passages
Restrictive lung disease - loss of lung compliance
What are infections due to?
Pathogenic microorganisms - infections inhibited by immune but overcome as respiratory tract is warm, moist and alveoli is a good supply of nutrient rich blood
What can cause increased incidence of respiratory infections?
Poor ventilation of lungs
What can infections lead to?
Inflammation - a term ending in an itis indicates it e.g bronchitis
What can reduce respiratory infection?
Use of antiobiotics or vaccinations i.e flu jab
What are e.g of URT infections?
Common cold - viral affects nose, throat, sinuses, sinusitis, tonsilitis, , cough, runny nose, sneezing
What are e.g of LRT infections?
Pneumonia - inflammatory affects alveoli, caused by bacteria streptococcus pneumoniae can be viruses or funghi
Tuberculosis - affects lungs caused by myobacterium tuberculosis
What is Obstructive lung disease?
Narrowing of air passage. asthma, bronchitis, emphysema - decrease airflow during expiration
What is asthma?
Obstructive inflammatory chronic lung disease, recurrent, reversible airway obstruction by bronchialhyperresponsivenes, allergic component, wheeze, SOB, nocturnal cough, bronchial muscles contract bronchospasms, treated with bronchodilators or anti-inflam drugs
What is status asthmaticus?
Sever acute asthma - medical emergency
What is Emphysema?
COPD along with chronic bronchitis, breathlessness, cough, plegm, loss of elastin, smoking main cause
What does smoking do?
Allows inhalation of nicotine accumulate in pulmonary epithelial cells - act directly on alveolar macrophages and neutrophils so they increase secretion of enzyme elastase and oxygen radicals
What is elastas?
A serine protease that targets ECM elastin - elastin gives lungs elastic properties, destruction decreases lung elasticity
What produces elastase?
Neutrophils and macrophages and deactivated by serine protease inhibitor antitripsin
a1-antitrypsin inhibited by oxygen radicals
What is the gene for a1-antitrypsin?
Polymorphic, 3 major alleles MSZ 95% normal mm genotype
What major alleles does not cause disease?
MZ and SS - SZ and ZZ does
What is restrictive lung disease?
Pulmonary fibrosis - lung compliance decreases , vital capacity drops, peak flow high - elastic tissue replaced by inelastic - caused by asbestos, silica and coal dust
WHAT Malignant tumours cause cancer?
Lung cancer, mesothelioma
What pleural cavity diseases are there?
Pleural mesothelioma, effusion (fluid in pleural cavity) Pneuomothorax (hole in pleura)
What pulmonary vascular disease are there?
Embolism, arterial hypertension, oedema, haemorrgage, inflammation
What 3 things of age effect respiratory system?
Elastic tissues deteriorate - alter lung compliance and low vital capacity
Arthritic changes - restrict chest movements
Emphysema - indiv >50 , smoke
What pulmonary function test diagnose disease?
Spirometry, Vitalograph, Peak flow meters, Blood gas PH
What is respiratory rate volumes?
Adapt to o2 demands - number of breaths per min and volume of air passed so tidal volume
What is respiratory minute volume?
Amount of air moved per min of total volume of air that passes through
RRxTV
Measures pulmonary ventilation, 6L healthy
What is alveolar ventilation?
part that reaches alveolar exchange surfaces - volume of air remaining in anatomical dead space where gas exchange doesnt occur
TV-ADSxRR
How is pulmonary air flow measured?
Spirometry for flow of air in and out of lungs, measures pulmonary volumes and capacities
What is normal FEV1?
> 80
severe is <50
What is FVC in mild obstructive lung disease?
Normal but fev1 is low, mild between 65-80
What is fvc in restrictive lung disease?
FVC and fev1 is low
What is measured for blood gas ph?
measure partial pressures of CO2 and O2 and PH in blood
