Adobe Systems Physiology department 1 Respiratory system. Adobe Systems Physiology department 2 A22: Hypoxia and ischemia ̶Hypoxia is a general name for a lack of oxygen in the body or individual tissues ̶Ischemia, meaning insufficient blood flow to a tissue, can also result in hypoxia ̶The most common types of hypoxia: ̶Hypoxic ̶Transport (anemic) ̶Ischemic (stagnation) ̶Histotoxic O2 O2 O2 O2 ERY ERY ERY: ♀ 3.4 – 4.4 * 1012/l ♂ 4.5 – 5.5 * 1012/l pO2: 21kPa Adobe Systems 3 A22: Hypoxia and ischemia ̶Hypoxic: ̶physiological: stay at higher altitudes ̶↓ pO2; N Ery ̶pathological: hypoventilation during lung or neuromuscular diseases ̶↓ ventilation; N pO2; N Ery ̶Transport (anemic): ̶reduced transport capacity of blood for oxygen (anemia, blood loss) ̶N pO2; ↓ Ery/Hb ̶Ischemic (stagnation): ̶restricted blood flow to tissue (heart failure, obstruction of an artery) ̶N pO2; N Ery ̶Histotoxic ̶cells are unable to utilize oxygen (cyanide poisoning) ̶N pO2; N Ery ̶ Adobe Systems Physiology department 4 A25: Lung ventilation, volumes, measurement ̶Ventilation, or breathing, is the movement of air through the conducting passages between the atmosphere and the lungs ̶Principle: determination the air flow velocity from the measured pressure differences between the inner and outer spirometer membranes, the volumes being calculated (PowerLab spirometry) ̶ Adobe Systems Physiology department 5 A25: Lung ventilation, volumes, measurement ̶Tidal volume (TV) – the volume of air that enters the lungs during each inspiration (or the volume that is exhaled during every expiration). ̶Inspiratory reserve volume (IRV) – the maximal amount of additional air that can be drawn into the lungs by determined effort after a normal inspiration at rest. ̶Expiratory reserve volume (ERV) – the additional amount of air that can be exhaled from the lungs by determined effort after a normal expiration. ̶Residual volume (RV) – the volume of air still remaining in the lungs after the most forcible expiration possible. ̶ V [l] Vt (0,5 l) IRV (2,5 l) ERV (1,5 l) RV (1,5 l) Adobe Systems Physiology department 6 A25: Lung ventilation, volumes, measurement Lung capacity: ̶VC = VT + IRV + ERV ̶TLC = VC + RV ̶FRC = ERV + RV ̶IC = IRV + VT ̶EC = ERV + VT ̶ Vt (0,5 l) IRV (2,5 l) ERV (1,5 l) RV (1,5 l) V [l] Dynamic lung volumes: ̶VE ̶MMV ̶ Adobe Systems Physiology department 7 A25: Lung ventilation, volumes, measurement Dynamic lung volumes ̶ V [l] Time [s] 1 s FEV1 ―FVC – the maximum volume of air that can be exhaled after maximum inhale ―FEV1 – the volume of air exhaled with the greatest effort in 1 second after maximum inhale ―FEV1/FVC (%) – Tiffeneau index – around 0,8 (80 %) Adobe Systems Physiology department 8 A25: Lung ventilation, volumes, measurement 1 s V [l] Time [s] 1 s V [l] Time [s] FEV1 FEV1 FVC > FVC Obstruction lung disease (FVC=N; FEV1=↓) ―tracheal stenosis ―astma bronchiale ―CHOPN ―tumor Restrictive lung disease (FVC=↓; FEV1=N) Pulmonarzy etiology ―pulmonary fibrosis ―lung resection ―pulmonary edema ―pneumonia Extrapulmonary etiology ―ascites ―kyphoscoliosis ―burns ―high diaphragm condition Adobe Systems Physiology department 9 A25: Lung ventilation, volumes, measurement V1 c1 V2=RV+V1 c2 Helium dilution method – residual volume Adobe Systems Physiology department 10 A26: Dead space, measurement Adobe Systems Physiology department 11 A46: Compliance of lungs. Respiratory work. Pneumothorax ̶According to etiology: ̶traumatic pneumothorax (due to an injury) occurs if the chest wall is perforated or during an injury of the esophagus, bronchi, and during rib fractures. ̶spontaneous pneumothorax ̶primary idiopathic pneumothorax (without any known cause) may occur in tall healthy young men with an incidence of pneumothoraxes in the family, ̶secondary pneumothorax arises as a consequence of lung diseases (such as COPD or cystic fibrosis), ̶iatrogenic pneumothorax (due to medical procedures) occurs during invasive medical examinations such as transparietal aspiration biopsy, subclavian vein catheterization, or mechanical ventilation with positive pressure. ̶artificially induced (deliberate) pneumothorax is used during thoracoscopy, an endoscopic examination the thoracic cavity. ̶According to the communication of the pleural space with its surroundings ̶open pneumothorax (when the hole in the pleural space remains open, the air in the pleural cavity moves back and forth with each breath of the patient) ̶closed pneumothorax (when a small opening through which air enters the pleural cavity closes) ̶valvular pneumothorax (the tissue of the lungs or the chest wall covers the hole in such a way that a valve emerges, this valve allows air to flow inside during inspiration, but it prevents the air from leaving the pleural cavity during exhalation). ̶ Adobe Systems 12 A47: Composition of atmospheric and alveolar air. Gas exchange in lungs and tissues. BAROMETRIC PRESSURE IN SEA LEVEL 1 atmosphere = 760 mm Hg 1 kPa = 7,5 mm Hg (torr) O2 20.95 % FO2 @ 0,21 N2 78.09 % FN2 @ 0,78 CO2 0.03 % FCO2 @ 0,0004 COMPOSITION OF DRY ATMOSPHERIC AIR Adobe Systems Physiology department 13 A47: Composition of atmospheric and alveolar air. Gas exchange in lungs and tissues. Adobe Systems Physiology department 14 A48: Transport of O2. Oxygen - haemoglobin dissociation curve. Transport of CO2 O2 is transported in two forms : ―physically dissolved(1%) ―in chemical bond with Hb (99%) ―Fetal hemoglobin(2α, 2g) ―Methemoglobin (Fe3+) ―Carboxyhemoglobin (CO) ―Carbaminohemoglobin (CO2) ―Oxyhemoglobin (O2) ―Deoxyhemoglobin (without any gases) Adobe Systems Physiology department 15 A48: Transport of O2. Oxygen - haemoglobin dissociation curve. Transport of CO2 Dissociation curve of Hb is influenced by: ―pH of blood ―pCO2 of blood ―Temperature ―Concentration of 2,3 - BPG Adobe Systems Physiology department 16 A48: Transport of O2. Oxygen - haemoglobin dissociation curve. Transport of CO2 CO2 is transported in next forms : ―physically dissolved(5 %) ―in the form of bicarbonate anions (85%) ―in chemical bond with Hb (10%) CO2 + H2O H2CO3 KAH H+ + Hb HCO3- Cl- CO2 H+ + HCO3 - CO2 + H2O Hb H2CO3 KAH Cl- CO2 Adobe Systems Physiology department 17 A49: Regulation of ventilation Adobe Systems Physiology department 18 A49: Regulation of ventilation Adobe Systems Physiology department 19 A49: Regulation of ventilation