Respiratory

Question 1

What causes pathologies regarding the mechanics of breathing?

Answer 1

Neuromuscular disorders (e.g. Guillian-barre syndrome), obstruction, infection, paralysis, etc… (issues relating to rib cage and respiratory muscles)

Question 2

What are some pathologies regarding the diffusion of gas?

Answer 2

Pulmonary oedema; excess fluid in the lungs, which collects in the air sacs, causing difficult breathing.
Pneumonia; a form of acute respiratory infection (alveoli are filled with pus and fluid).
Embolus; unattached mass that travels through the bloodstream and may create obstructions.

Question 3

What are some pathologies regarding the transport of gas?

Answer 3

Anemias; hemoglobin concentration in RBCs lower than normal.
Polycythemia; having a high concentration of RBCs in the blood slowing blood transportation.
Carbon monoxide poisoning; CO has a higher affinity to hemoglobin than oxygen and can therefore deprive blood cells of oxygen.

Question 4

What causes pathologies regarding the control of breathing?

Answer 4

Trauma(e.g. stroke, spinal injury), drugs(e.g. morphine), sleep apnea

Question 5

What are the three categories of respiratory pathologies? Outline and give examples.

Answer 5

Obstructive; obstruction with the airways (e.g. COPD)
Restrictive; restricting air entering the lungs (e.g. disease of the rib cage and respiratory muscles)
Disorder of vasculature; disruption of blood supply to lungs (e.g. hypertension)

Question 6

Symptoms of respiratory pathology?

Answer 6

Cough, dyspnoea, wheezing, fever, tachypnoea, etc…

Question 7

Diagnosis & testing?

Answer 7

Spirometry; measures the volume of air a patient can inhale and exhale.
Arterial blood gases; an invasive test that measures oxygen, CO2, and pH of the blood.
DLCO; measures the lungs’ ability to transfer gas from inspired air to blood stream (low DLCO = loss of vasculature[e.g. COPD]).
FeNO; measures amount of NO in patients breathe which helps indicate inflamed airways(e.g. asthma).

Question 8

Describe the main classifications of abnormalities.

Answer 8

Respiratory disorders; fibrosis 
Airway disease; asthma, COPD
Pleural cavity; effusion, tumour, etc…
Chest wall effects; pregnancy 
Muscle disorders; polio, neuromuscular disease

Question 9

What are the clinical features of asthma?

Answer 9

Wheezing, tight chest, cough, bronchodilator responsiveness, etc…

Question 10

Define asthma.

Answer 10

Airways narrow and swell and may produce excess mucus making breathing very difficult.

Question 11

Outline the pathologies that commonly occur with asthma (up to 4).

Answer 11

Narrowing of airway; steps of responsive inflammatory changes.

• oedema; fluid in lungs and air sacs.
• cellular infiltration; infiltration of the airway by inflammatory cells.
• disruption of epithelial layer; in asthma, the bronchial epithelium is modified, appears fragile.
• mucous gland hypertrophy; airway mucous hyper-secretion is indicative of poor asthma control and also contributes to hyper responsiveness.

Question 12

Describe the remodeling in asthma patients.

Answer 12

Remodeling; structural changes that occur in the airways relevant to asthma and other respiratory/airway disease. Patients with chronic asthma have a prevalent remodeling appearance (muscle layer increases in thickness, increase in fibrosis and inflammatory cells)

Question 13

Outline the Pathogenesis of asthma and the two affects that may occur.

Answer 13

Pathogenesis; (LOOK AT NOTES)

1. Rapid effect; causes bronchospasm(muscle tightens which also makes airway narrow) (treatment: bronchodilator)
2. Slow effect; airway inflammation (treatments: steroids)

Question 14

Define and distinguish extrinsic and intrinsic asthma.

Answer 14

Extrinsic asthma is caused by an allergic reaction to something in your environment that your immune system views as “foreign” to your body. Intrinsic asthma is any type of asthma that isn’t caused by an allergy.

Question 15

What factors trigger asthma/asthma attacks?

Answer 15

Histamine, NSAIDs, allergens, pollutants, etc…

Question 16

What are asthmas clinal features in regards to Spirometry?

Answer 16

In presence of asthma triggering stimuli, airway narrowing and obstructive Spirometry can patten. (Significant decrease in expiration and inspiration compared to normal)

Question 17

Describe/Outline COPD.

Answer 17

Irreversible progressive airflow obstruction. COPD covers a range of heterogenous conditions including:
Emphysema; permanent destruction enlargement of airspace’s without obvious fibrosis.
Chronic bronchitis; chronic or recurrent increase in bronchial secretions sufficient to cause expectoration.

Question 18

What are the risk factors of COPD?

Answer 18

Most common: smoking.
Host factors; genetics, alpha1 antitrypsin deficiency.
Environmental factors; air pollution, nutrition, infection, etc..

Question 19

Symptoms of COPD?

Answer 19

Cough, wheeze, sputum, chest pain, weight loss/anorexia(indicates worsening prognosis), respiratory failure(in advanced disease), etc…

Question 20

Outline the Pathogenesis of COPD.

Answer 20

Pathogenesis; (LOOK AT NOTES)

Question 21

What are COPDs clinical features in regards to Spirometry?

Answer 21

Loss of parenchyma leads to loss of elastic recoil and airway collapse in ventilation. (Increase in expiratory time).

Question 22

Stimuli, routes, results, COPD?

Answer 22

Inflammation to stimuli -> airway disease(chronic bronchitis) OR parenchyma disease(emphysema) -> airflow limitation.

Question 23

Define restrictive ventilatory disorders. Examples?

Answer 23

RVD typically reduce the proper expansion of the lungs. Examples of RVD include: abnormalities in lung parenchyma, chest wall disease(e.g. scoliosis), neuromuscular disease, etc…

Question 24

Outline some abnormalities of the lung parenchyma.

Answer 24

Pulmonary fibrosis; lung disease that occurs when lung tissue (alveoli) becomes damaged and scarred resulting in stiffness and reduced expansion.
Sarcoidosis; a disease characterized by the growth of tiny collections of inflammatory cells (granulomas) in lungs.
Pneumoconioses; is one of a group of interstitial lung disease caused by breathing certain kinds of dust particles that damage lungs (e.g. asbestosis, silicosis, etc…)

Question 25

Define parenchyma and stroma.

Answer 25

Parenchyma = functional tissue
Stroma = structural tissue

Question 26

Define pneumoconioses. Why is it so harmful?

Answer 26

Lung impairment due to inhalation of inorganic dusts(e.g. tin/stannosis, silica/silicosis, asbestos/asbestosis, etc…). These are so harmful because the immune system isn’t equipped to deal with INORGANIC foreign compounds.

Question 27

Define chest wall disease. Examples? Why is it so harmful?

Answer 27

CWD are usually the same as those causing spinal deformity (e.g. scoliosis). The effect of severe scoliosis is most often restrictive due to autonomical distortion of the chest, leading to reduced lung volumes, chest wall muscles inefficiency, etc…

Question 28

What is ankylosing spondylitis?

Answer 28

Ankylosing spondylitis; resulting in gradual immobility of vertebrae joints and fixation of ribs, again leads to restrictive disorders.

Question 29

How do neuromuscular disorders affecting respiratory functions?

Answer 29

Neuromuscular disorders affecting the spinal cord, peripheral nerves, or respiratory muscles can reduce the vital capacity(ability to maintain normal pressures) on Spirometry.

Question 30

Why does pulmonary oedema occur?

Answer 30

Starling’s Equation encompasses four forces, two pressure aiding fluid to expels out of the lungs and the other two keeping fluid away from the lung. The issue is that in some occurrences gaps in the alveolar-capillary membrane can be present, due to epithelial and endothelial damages(could be due to pathogens). Once that membrane gets damaged its very easy for fluid and protein to leave, and once proteins leave water follows. This is all typically caused by high BP, aspiration, or pneumonia.

Question 31

What is Cheyne-strokes breathing?

Answer 31

A rare abnormal breathing pattern(fast, shallow breathing followed by heavier breathing and sometimes no breathing) that typically occurs when asleep.

Question 32

Describe the categories of spinal injuries.

Answer 32

C2, C3; usually fatal as there is an inability to breathe.

C4; quadriplegic and breathing difficulty.

Question 33

Distinguish the outlines and descriptions of ‘poor ventilation’ and ‘poor diffusion’.

Answer 33

Ventilation; a mucus plug can stop air from entering the lungs, restricting ventilation, and causing hypoxia -> brain death.
Diffusion; if an embolus is in the pulmonary artery, it can stop blood flow across the lungs and again causing hypoxia -> brain death.