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OXYGEN DEMAND, REFERENCES
Biozone
ESA Study Guide, Trinity - Coggle…
OXYGEN DEMAND
blood
blood vessels
veins
pulmonary vein
- sends oxygenated blood from the lungs to the heart
arteries
pulmonary artery
- brings deoxygenated blood from the heart to be oxygenated by the lungs
haemoglobin
- respiratory pigment (reason blood is red)
- binds with oxygen diffused across cell membrane
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gas transport
- moves substances
- maintains pH balance of blood
starts in cells at mitochondria
- CO2 produced as a byproduct of cellular respiration
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starts in lungs
bronchiole
alveoli
- increases surface SA:V ratio
capillaries
gas exchange membrane
- thin for rapid diffusion (concentration gradient)
- capillaries are very close to tissue for more efficient diffusion
- passive diffusion (concentration gradient)
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Oxygen levels in the blood are too low (HYPOXIA)
- STIMULUS, CO2 levels are too high (internal) changes pH of blood
- cause, increased respiration (more demand for oxygen), high exercise --> ATHELETES
change in pH detected by chemoreceptors
sends nerve impulse to medulla (acts similar to hypothalamus)
- medulla = respiratory regulation centre in the brain
- CONTROL
contractions are faster and stronger
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less O2 for aerobic respiration therefore body cells carry out anaerobic respiration
- produce lactic acid which lowers blood pH
low O2 reduces cellular respiration rate, lower ventilation rate therefore higher CO2 concentration in the blood
- weak acid therefore shifts pH
effects gas exchange
gas exchange acts on concentration gradients
- levels of O2 and CO2 must be balanced (equilibrium) or diffusion across semipermeable membrane wont occur
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pH stimulates red blood cells to produce 2,3-diphosphoglycerate
- alters the shape of hameoglobin so they release O2 needed to supply oxygen demand
- Hb returns to lungs less saturated than normal
active tissues such as muscles have high oxygen demand therefore producing high levels of CO2 and heat energy (THERMOREGULATION)
Oxygen levels in the blood too high (HYPOXEMIA)
- STIMULUS, CO2 levels are low (internal) changes blood pH
change in pH detected by chemoreceptors
sends nerve impulse to medulla (acts similar to the hypothalamus)
- medulla = respiratory regulation centre in the brain
- CONTROL
slower and weaker contraction
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