Diving and Air Breathing Marine Animals Flashcards
What is the deepest diving non-mammal?
leatherback turtle
What are the 2 greatest physiological problems with deep diving?
Effects of water pressure and temporary anoxia
Name 2 adaptations to temporary anoxia
increases oxygen carrying capacity of blood, postural bradycardia
How does water pressure increase with depth?
1 atmosphere every 10 metres
Name the 2 effects of increasing water pressure
direct mechanical compression, increase in air pressure supply (to match external water pressure)
Name 3 adaptations of marine mammals for deep diving?
no sinuses, lungs able to withstand collapse, modified thorax to allow painless compression (e.g. short sternum and modified/free ribs)
Give an advantage and disadvantage of un-lobulated lungs (NOT divided into chambers) in marine mammals
allows for reversible collapse, but risks the spread of infection
Give an advantgae of lung collapse and short impermeable airways
minimises hyperbaric oxygen and nitrogen toxicity, as it stops gases under high pressure from passing into the bloodstream
What animals make up the cetaceans?
whales, dolphins, and porpoises
What pressure adaptation do the cetaceans have?
waxy plug in middle ear, also with acoustic properties (for better navigation and prey detection)
What pressure adaptation does sea turtles have?
a flexible plastron (front of turtle) to allow for lung collapse
Define apnoea
a lack of gaseous exchange
Name an unwanted consequence of hyperventilating before deep freediving
Shallow water blackout: lungs expand on ascent, causing a drop in partial pressure of oxygen in the lungs and diffusion in from the blood, starving the brain.
What is caisson disease?
illness that affected bridge construction workers that led to scientific study of diving physiology/effects of breathing at increased pressure
What causes decompression sickness?
rapid reduction to from depth to surface air pressure, causing dissolved gases to form bubbles
Name 4 effects of decompression sickness
excessive clotting, loss of blood proteins, tissue damage, bone necrosis (death of osteoblasts)
Who produced the first sets of decompression tables and decompression chambers?
J.S. Haldane
Name 3 physiological problems with a new-found ability to dive deeper?
Nitrogen narcosis, oxygen toxicity, high pressure nervous syndrome (HPNS)
What causes nitrogen narcosis?
at increased partial pressures nitrogen dissolves readily into lipids and particularly those of the CNS, where it acts as an anaesthetic gas (between 30-60m)
What level of oxygen exposure causes lung damage?
above 0.6atm
What level of oxygen exposure produces involuntary muscle spasms leading to fatal convulsions?
above 2atm
Which gas is mixed with oxygen for deeper diving (150m+)?
helium
What is HPNS?
High pressure nervous syndrome, caused by fast descents on oxy-helium
Give 2 animals physical adaptations to reduce oxygen usage?
streamlining (to minimise energy use) and insulation (with fur or blubber)
