Lectures on respiratory physiology Respiration under stress Respiration
- Slides: 27
Lectures on respiratory physiology Respiration under stress
Respiration under stress • Exercise • High altitude • Diving • Space flight
Exercise
Respiratory responses to exercise
Comparison of the increases in blood flow and ventilation
Additional changes with exercise Pulmonary artery, venous and capillary pressures rise Recruitment and distension of capillaries Pulmonary vascular resistance falls Pulmonary diffusing capacity increases Shifts of the O 2 dissociation curve Capillaries open up in exercising muscle Systemic vascular resistance falls
High altitude
Decrease of barometric pressure with altitude
Climber on the Everest Summit
Polycythemia at 4600 m altitude • Hemoglobin concentration 19. 8 g/dl • Arterial PO 2 45 mm Hg • O 2 saturation 81% • O 2 concentration 22. 4 ml/dl
PO 2 cascade at sea level and high altitude
Other features of acclimatization • Shifts of the O 2 dissociation curve • Increased concentration of capillaries in muscle • Changes in oxidative enzymes in cells
Uneven hypoxic pulmonary vasconstriction exposes some capillaries to high pressure
Diving
Physiological Stresses with Diving Mechanism of decompression sickness Treatment and prevention of decompression sickness Use of helium-oxygen for breathing Saturation diving Inert gas narcosis CNS toxicity caused by high-pressure oxygen Pulmonary oxygen toxicity Hyperbaric oxygen therapy
Concentration of dissolved O 2 in the blood with hyperbaric therapy • • • Barometric pressure = 3 x 760 mm Hg Alveolar and arterial PO 2 exceed 2000 Solubility of O 2 is 0. 003 ml/dl/mm Hg Dissolved O 2 = 6 ml/dl This exceeds the normal arterial-venous difference for O 2
Space flight
Effects of gravity on the lung
Shuttle Launch
Spacelab in the Bay of the Shuttle
Spacelab under 1 G Conditions
Spacelab during Microgravity
Study of Pulmonary Function in Microgravity • Package of 9 tests • Duration 31 minutes in microgravity • Crew member performs test on himself • Data available on ground in real time • Comprehensive assessment of pulmonary function
Astronaut with the lung function experiment
Pulmonary function in microgravity I • Increased pulmonary capillary blood volume • Increased pulmonary diffusing capacity • Increased cardiac output and stroke volume • More uniform distribution of blood flow and ventilation • FRC between upright and supine at 1 G • Residual volume reduced • Changes in the deposition of aerosol
Pulmonary function in microgravity II • O 2 uptake and CO 2 output unchanged • Alveolar PO 2 and PCO 2 unchanged • No significant impairment of lung function during two weeks of microgravity • On return from six months on the International Space Station, lung function soon returned to pre-flight conditions
- Rbc formation stages
- Laynx
- Trachea
- Human.respiratory.system
- Respiratory zone of the respiratory system
- Control of breathing
- Dive physiology
- Pulmonary gas exchange and transport diagram
- Physiology of respiration
- Stimulus for breathing
- Respiratory stress
- Internal respiration
- External respiration vs internal respiration
- True strain formula
- Chapter 10 stress responses and stress management
- What is the definition of axial stress
- Communication under stress
- Style under stress assessment
- Dr sohail lectures
- Do words have power
- Hugh blair lectures on rhetoric
- Data mining lectures
- Bhadeshia lectures
- Reinforcement learning lectures
- Hegel three forms of art
- Define aerodynamics
- Step wise project planning
- Ota core curriculum