Diving and Air Breathing Marine Animals

Question 1

What is the deepest diving non-mammal?

Answer 1

leatherback turtle

Question 2

What are the 2 greatest physiological problems with deep diving?

Answer 2

Effects of water pressure and temporary anoxia

Question 3

Name 2 adaptations to temporary anoxia

Answer 3

increases oxygen carrying capacity of blood, postural bradycardia

Question 4

How does water pressure increase with depth?

Answer 4

1 atmosphere every 10 metres

Question 5

Name the 2 effects of increasing water pressure

Answer 5

direct mechanical compression, increase in air pressure supply (to match external water pressure)

Question 6

Name 3 adaptations of marine mammals for deep diving?

Answer 6

no sinuses, lungs able to withstand collapse, modified thorax to allow painless compression (e.g. short sternum and modified/free ribs)

Question 7

Give an advantage and disadvantage of un-lobulated lungs (NOT divided into chambers) in marine mammals

Answer 7

allows for reversible collapse, but risks the spread of infection

Question 8

Give an advantgae of lung collapse and short impermeable airways

Answer 8

minimises hyperbaric oxygen and nitrogen toxicity, as it stops gases under high pressure from passing into the bloodstream

Question 9

What animals make up the cetaceans?

Answer 9

whales, dolphins, and porpoises

Question 10

What pressure adaptation do the cetaceans have?

Answer 10

waxy plug in middle ear, also with acoustic properties (for better navigation and prey detection)

Question 11

What pressure adaptation does sea turtles have?

Answer 11

a flexible plastron (front of turtle) to allow for lung collapse

Question 12

Define apnoea

Answer 12

a lack of gaseous exchange

Question 13

Name an unwanted consequence of hyperventilating before deep freediving

Answer 13

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.

Question 14

What is caisson disease?

Answer 14

illness that affected bridge construction workers that led to scientific study of diving physiology/effects of breathing at increased pressure

Question 15

What causes decompression sickness?

Answer 15

rapid reduction to from depth to surface air pressure, causing dissolved gases to form bubbles

Question 16

Name 4 effects of decompression sickness

Answer 16

excessive clotting, loss of blood proteins, tissue damage, bone necrosis (death of osteoblasts)

Question 17

Who produced the first sets of decompression tables and decompression chambers?

Answer 17

J.S. Haldane

Question 18

Name 3 physiological problems with a new-found ability to dive deeper?

Answer 18

Nitrogen narcosis, oxygen toxicity, high pressure nervous syndrome (HPNS)

Question 19

What causes nitrogen narcosis?

Answer 19

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)

Question 20

What level of oxygen exposure causes lung damage?

Answer 20

above 0.6atm

Question 21

What level of oxygen exposure produces involuntary muscle spasms leading to fatal convulsions?

Answer 21

above 2atm

Question 22

Which gas is mixed with oxygen for deeper diving (150m+)?

Answer 22

helium

Question 23

What is HPNS?

Answer 23

High pressure nervous syndrome, caused by fast descents on oxy-helium

Question 24

Give 2 animals physical adaptations to reduce oxygen usage?

Answer 24

streamlining (to minimise energy use) and insulation (with fur or blubber)

Question 25

Give 2 physiological adaptations to reduce oxygen usage?

Answer 25

Bradycardia & shunting