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RESPIRATION. Overview of respiratory physiology. Air into/out of atmosphere and lungs Exchange of gases between lungs and bloodstream Exchange of gases between blood and body tissues. . 1. Pulmonary ventilation. AKA: breathing
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Overview of respiratory physiology • Air into/out of atmosphere and lungs • Exchange of gases between lungs and bloodstream • Exchange of gases between blood and body tissues.
1. Pulmonary ventilation • AKA: breathing • Inhalation/exhalation of air b/w atmosphere and alveoli (lungs) • Due to alternating pressure caused by muscle contraction/relaxation • Muscles: diaphragm, external intercostals
2. External respiration • Exchange of gases b/w alveoli and blood • Pulmonary capillaries gain O2 and lose CO2 • O2 in • Mostly hemoglobin (oxyhemoglobin) • Dissolved in plasma • CO2 transported as • Dissolved in plasma • Attached to hemoglobin (carbaminohemoglobin) • bicarbonate ion (HCO3-)
To what organ does this oxygen rich blood flow?
Gas exchange and transport in lungs • When deoxygenated blood goes to lungs it • picks up oxygen from alveoli and transports it back to the heart to be circulated throughout the body. • drops off CO2 by diffusion into alveoli and then exhaled
3. Internal respiration • Blood delivers O2 to body tissues and picks up CO2 • Cells need O2 for cellular respiration; CO2(Combines with water carbonic acid (H2CO3) HCO3- + H+) is waste product taken back to lungs
Factors affecting rate of breathing • Medulla oblongata (brainstem) sets rhythm • Influenced by levels of CO2 • Alcohol impairs medulla death • Nerve impulses connected to cerebral cortex: voluntary • Exercise triggers proprioceptors (nerve receptors monitoring joint and muscle activity). Impulse sent to medulla oblongata
THE BIGGER PICTURE… • Respiration is not the same thing as cellular respiration • You bring in oxygen so that your body cells can perform aerobic cellular respiration.
The Circle of Life • You breathe in oxygen and exhale CO2. • Producers then use the CO2 for photosynthesis which in turn give off O2
CELLULAR RESPIRATION&PHOTOSYNTHESIS • C6H12O6 + 6O2 6H2O + 6CO2 + energy (ATP) • Energy + 6CO2+ 6H2O 6O2 + C6H12O6
Fossil fuels • Health effects of burning: minor eye irritation, aggravate asthma, cause bronchitis, lung cancer
forensic application • Air left in lungs can be used to determine if a baby is born dead (stillborn) or died after birth. Fetal lungs contain no air. So if a piece of lung is placed in water and it sinks, the baby was stillborn.
Carbon monoxide (CO) • Colorless, odorless gas • Out competes O2 in binding to hemoglobin……no O2 = ill effects, possible death! • Produced by cars, generators • DON’T USE THEM INDOORS WITHOUT VENTILATION
Lung cancer • Metastasizes quickly • Most not diagnosed until well advanced • Low cure rate
Photosynthesis and cellular respiration are • Related processes because photosynthesis involves the production of energy, and respiration involves energy use. • Unrelated process because photosynthesis involves the production energy, whereas respiration involves energy use • Unrelated processes because respiration involves the production of energy, whereas photosynthesis involves energy use. • Related processes because respiration involves the production of energy, and photosynthesis involves energy use
Last thoughts • Nicotine constricts bronchioles – decreases air flow • With age: • Lung capacity decreases • Ciliary action of tract lining diminishes = elderly more susceptible to pneumonia
RESPIRATION VOLUMES AND CAPACITY • TV = tidal volume: volume of one breath • IRV = inspiratory reserve volume: amount of air forcibly inhaled beyond a normal inhalation • ERV = expiratory reserve volume: amount of air forcibly exhaled beyond the amount normally exhaled 1 breath equals 1 inhalation and 1 exhalation
VC = vital capacity = TV + IRV + ERV or max amount of air you can inhale/exhale • Residual volume = the air left in lungs after ERV • Total Lung capacity = vital capacity + residual volume