FC4: Diving (W13a) Flashcards
Challenges that air-breathing vertebrates have to deal with during submersion/diving? (2)
• High pressures underwater.
• Low O2 supply.
High pressures underwater attributes? (3)
• Increases with gases compressed.
• Sea level pressure = 1atm.
• Increases by 1atm every 10m in depth.
Problems accompanying diving? (5)
• High pressures.
• “The Bends”.
• O2 toxicity.
• Narcotic effect of gases.
• Low O2 supply.
The Bends is AKA? (2)
• Diver’s disease.
• Decompression sickness.
The Bends?
= condition caused by the formation of gas bubbles in the tissues & blood.
How does supersaturation occur in the Bends?
Because the diver experiences pressures twice as that of the surface, these high pressures cause gases to become more soluble & more nitrogen moves into the blood and tissues, therefore creating a supersaturated solution.
What increases the risk of Diver’s disease/Risk factors of Diver’s disease? (6)
• Rapid ascent.
• Long dives.
• Deep dives.
• High body fat.
• Age.
• Exercise during dive.
Decompression sickness treatment?
Recompression chamber.
What does Diver’s disease cause?
Barotrauma.
Difference between diving humans & diving mammals?
Diving humans breathe through an O2 tank underwater, while diving mammals exhale before diving.
Lung modifications of marine mammals? (4)
• Flexible chest wall (short & thick airways).
• Reinforcement of peripheral airways (bronchioles & trachea).
• Loss of respiratory bronchioles.
• Branchial sphincters.
What do diving mammals do before they enter water?
They exhale at the beginning of each dive.
Analogy of Diver’s disease?
Carbonated drink.
Why do divers take scuba tanks with Increased Helium?
It’s because Helium is less soluble & diffuses much faster than Nitrogen, therefore reducing the development of The Bends.
Contents of scuba tanks? (2)
• Reduced Nitrogen.
• Increased Helium.
How is High body fat a risk factor?
It’s because it requires such divers to degas for longer periods.
Symptoms of Decompression sickness? (4)
• Itching skin (external).
• Strong pain & aching muscles (bone).
• Hallucinations (brain).
• Acute respiratory depression (bloodstream).
Why do diving mammals exhale at the beginning of each dive?
It’s so that their lungs collapse completely under high water pressure, which helps reduce buoyancy.
O2 toxicity attributes? (4)
• Toxic limit of O2>1atm.
• Increased time (hrs) = Less O2 partial pressure inspired.
• Pulmonary limit (5atm of breathing 20% O2).
• CNS limit.
Narcotic effect of gases attributes? (2)
• Physiological & mental disturbances (“Martini effect”).
• He is used as the rate of diffusion is faster (moves out of body quicker due to low molecular weight).
O2 supply attributes? (4)
Enables longer duration underwater by:
• Increased O2 storage.
• Anaerobic processes.
• Decrease O2 consumption by lowering MR.
• Aquatic respiration.