Flashcards in INCORRECT EXAMPREP Q'S - RESPIRATORY Deck (25):
What do the walls of the trachea, bronchi and bronchioles consist of?
An outer fibrous layer with supporting pieces of cartilage & bronchial smooth muscle
How is bronchial smooth muscle arranged?
In clockwise and anticlockwise helical bands
- there is a matrix of elastic tissue supporting the muscles
What is surfactant secreted by? What is it made up of? What is its action on the body?
From type II pneumocytes in alveoli, essentially a mix of lipids and proteins, the major component being dipalmitoylphosphatidylcholine
Main action is to lower alveolar surface tension which increases compliance of the lung (stiff lungs have low compliance)
The change in lung volume per unit change in airway pressure
To which structure do the hilar lymph nodes drain?
How many lobar bronchi are present within the left lung?
How long does equilibration of pO2 take to achieve in the pulmonary capillaries?
0.25 seconds (approx)
Transpulmonary pressure is the difference between the alveolar and intrapleural pressure. At what stage of pulmonary ventilation is this pressure greatest?
End of respiration
At the start of normal respiration, what is the difference (in mmHg) between intrapulmonary pressure and atmospheric pressure?
The gap between the alveolar space and the pulmonary circulation is known as the gas-blood barrier. What type of cells does this barrier consist of?
Type I and Type II alveolar cells
How many times does the respiratory tree branch from trachea to the alveoli?
- giving rise to around half of the 250-300 million alveoli
What intermediate extrinsic muscle of the back act on the ribs to assist respiratory movement?
Where are the respiratory changes associated with coughing and sneezing produced?
Say whether the following are obstructive or restrictive lung diseases; (i) ARDS (ii) chronic bronchitis (iii) pneumothorax (iv) pulmonary embolism (v) pulmonary fibrosis?
1. What are the general causes of pulmonary oedema? 2. What is the commonest cause? 3. What are other causes of increased venous hydrostatic pressure?
1. Increased pulmonary venous hydrostatic pressure, reduced plasma oncotic pressure, increased permeability of the alveolar capillary wall and blockage of lymphatic drainage
2. increased pulmonary venous hydrostatic pressure due to LVF
3. mitral stenosis and severe aortic stenosis
1. What is primary tuberculosis best described as? 2. What is the immune reaction mediated by?
1. Granulomatous lesions with central caseation, surrounded by epitheloid and Langerhans giant cells
- the initial focus of infection is a small subpleural granuloma accompanied by granulomatous hilar lymph node infection. These make up the Gohn complex
2. Type IV hypersensitivity where killing is mediated by T lymphocyte recruitment and actiavtion of macrphages by cytokines - this inflammatory reaction causes necrosis
Define (i) Type 1 respiratory failure (ii) Type 2 respiratory failure.
(i) low oxygen and normal carbon dioxide (or decreased)
- typically caused by V/Q mismatch, high altitude, hypoventilation, shunt
(ii) low oxygen and increased CO2
- COPD, asthma, Guillain-Baree syndrome, extreme obesity
Why is recovery from a major operation a significant risk factor for pulmonary embolism? What are 3 other risk factors?
Pulmonary emboli tend to originate from thrombi in legs which are initiated by valves causing turbulent blood flow. The flow of blood in legs depends on calf muscle contraction so immobilation is a major risk factor. During an op BP may fall and stasis in leg veins may occur.
Malignancy - as may increase blood viscocity
What type of lung tumour metastasises very early, is made up of blue cells and may secrete hormones e.g. ADH?
Small cell carcinoma
1. When does respiratory failure occur? 2. What can it be caused by?
1. When hypoxia and CO2 retention occur due to ineffective gas exchange
2. Ventilation defects, perfusion defects, or defects of gas exchange
What are causes of (i) ventilation defects (ii) V/Q mismatch (iii) Defects of gas exchange?
(i) mechanical factors (obesity, severe abnormal curvature of spine)
Muscle weakness (muscular dystrophy, paraplegic poliomyelitis)
loss of lung volume (collapse of lung lobe)
(ii) multiple pulmonary emboli
(iii) pulmonary fibrosis or emphysema
What are the main afferent inputs of the cough reflex?
Stimuli to the trachea or larynx
What is sarcoidosis?
A multisystem disorder that often mainly affects mediastinal lymoh nodes and lungs; pt may be asymptomatic or have non-specific tiredness and cough. Presence in the lung of discrete non-caseating granulomas
What do pulmonary emboli do to the (i) anatomical (ii) physiological dead space?
(ii) significantly increased