Pathophysiology of the respiratory system

1. Pathophysiology of the respiratory system #AnimPhysio2015

2. Oxygen dissociation curve 2 3 diphosphoglyceric acid

3. Methods for studying resp insuff • Arterial blood gases • Blood pH • Measurement of max exp flow

4. Exp flow-volume curve

5. Reasons for respiratory dysfunction • Dysfunction of the respiratory neurons; • Chest pathology • Respiratory muscles and diaphragm pathology; • Injure of pleura; • Obstructive lung disease; • Restrictive lung disease.

6. The pathological factors impair metabolism, structure and function of nerve cells. • They are hypoxia, hypoglycemia, toxic agents, inflammatory processes in the brain tissue, compression of the medulla, traumas, circulatory disorders in the brain.

7. Emphysema • Excess air in lungs • Destructive process / smoking / chronic infection / irritation • Chronic obstruction • Entrapment of air, overstretching of alveoli Subcutaneous emphysema

8. Pneumonia • Bacterial, pneuomococci • Viral

9. Atelectasis • Collapse of alveoli • Obstruction • Absence of surfactant

10. Asthma • Spastic contraction of the smooth muscle in the bronchioles, which partially obstructs the bronchioles and causes extremely difficult breathing • Occurs in 3 to 5 per cent of all people at some time in life.

11. Causes of bronchial asthma

12. Tuberculosis

13. Hypoxia • Inadequate oxygenation of the blood in the lungs because of extrinsic reasons • Deficiency of oxygen in the atmosphere • Hypoventilation (neuromuscular disorders) • Pulmonary disease • Hypoventilation caused by increased airway resistance or decreased pulmonary compliance • Abnormal alveolar ventilation-perfusion ratio (including either increased physiologic dead space or increased physiologic shunt) • Diminished respiratory membrane diffusion • Venous-to-arterial shunts (“ right-to-left” cardiac shunts) • Inadequate oxygen transport to the tissues by the blood • Anemia or abnormal hemoglobin • General circulatory defi ciency • Localized circulatory defi ciency (peripheral,cerebral, coronary vessels) • Tissue edema • Inadequate tissue capability of using oxygen • Poisoning of cellular oxidation enzymes • Diminished cellular metabolic capacity for using oxygen, because of toxicity, vitamin deficiency, or other factors

14. Artificial respiration

15. Heart lung by pass (open heart surgery)

17. Damage to the chest • Thecontaminationofairinthepleuralcavityiscalledpneumothorax (opened, closed,valvular). • If air can enter the pleural cavity and go out by place of trauma, this is opened pneumothorax. • In case of shift the damaged tissues the air cannot go out the pleural cavity and closed pneumothorax develops. • When mild tissues in the place of trauma permit entering of air and prevent outflow of air from the pleural cavity, the valvular pneumothorax develops.

18. Damage of the respiratory muscles • Damage of motoneurons of spinal cord that control respiratory muscles may occur due to inflammatory and degenerative processes (with amyotrophic lateral sclerosis, poliomyelitis, syringomyelia), due to intoxication (strychnine, tetanus toxin). • Violation of the conduction impulses in the peripheral nerves that supply respiratory muscles can occur because of inflammation, vitamin deficiency, trauma. Diaphragmatic nerve lesion leads to paralysis of the diaphragm, which manifests its paradoxical movements according to changes in pressure in the chest cavity - at the inhalation diaphragm rises, at the exhale – gets plant. Violation of neuromuscular transmission of impulses occurs in myasthenia, botulism, introduction of muscle relaxants. In all these cases, the ventilation function get disturbed.

19. When obstructive respiratory insufficiency, airway can be broken due to their narrow, leading to increased resistance to air movement (when inhaled forensic particles, thickening of the walls of airways due to inflammation, muscle spasm of the larynx, bronchial compression due to swelling, inflammation, enlarged thyroid gland .)

20. Mechanism that limits maximal expiratory flow rate

21. Emphysema • In emphysema the lungs lose their elasticity and stretch considerably with less transpulmonary pressure, so there is lack of pressure from within bronchioles - their clearance decreases, increases resistance to air movement, difficult breath. • Exhalation becomes active due to decreased elasticity of the lungs, the pressure increases and bronchioles collapse, so alveoli are filled with residual air.

22. The alveoli filled with residual air because of emphysema

24. Pathology of the lung in end-stage cystic fibrosis Key features are: • the widespread mucus impaction of airways and bronchiectasis (U); • small cysts (C); • hemorrhagic pneumonia in lower lobe.

25. Atelectasis • Atelectasis caused by airway obstruction and absorption of air from the involved lung area on the left and by compression of lung tissue on the right.

26. Atelectasis • The right lung of an infant (left side of photo) is pale and expanded by air, whereas the left lung is collapsed.

27. Asphyxia • The first stage is characterized by deep and rapid breathing with a predominance of inspiratory phase (inspiratory dyspnea).• In the second stage begins a gradual decline in respiration rate against the background of deep respiratory movements. Phase exhalation prevails over the inspiratory phase (expiratory dyspnea).• In the third stage of the frequency and depth of respiratory movements decreased steadily up to a complete stop breathing. After a short term of absent respiration (preterminal pause) several rare deep respiratory movements are observed (terminal or agonic, breathing).• Stimulation of breathing at the beginning of asphyxia associated with direct and reflex excitation of carbon dioxide and respiratory center hipoksemichnoyu blood. With the growth inhibition of hypoxic brain come the respiratory center and complete paralysis of its functions. The appearance of terminal respiration explained by the excitation of neurons of the caudal medulla oblongata.

28. Obstruction of larynx leads to hypoxia А – normal larynx; В – Obstruction of larynx from edema caused by croup.

29. Violation of ventilation-perfusion ratio • To maintain the gas composition of blood it is important to not only the absolute value of alveolar ventilation, but the proper balance between ventilation and perfusion lung. The amount of blood flowing through the lungs for 1 min, equal to 4.5-5 liters, approximately corresponds to the value cardiac output.• The optimal ratio of alveolar ventilation and perfusion lung is 0.8 (4 l/ 5 l). It may vary upward or downward. In both cases, normal blood gas composition can not provide.• The predominance of ventilation pressure of oxygen in the alveoli in blood is sufficient, but blood carry out too much carbon dioxide (hipokapniya). If, however, ventilation is slower than perfusion, hypoxemia and hypercapnia occur.

31. Acute respiratory distress syndrome (ARDS)