8. How can we support life?
• Drips
• Feeding tubes
• Oxygen masks
• Ventilators
9. Is switching off life support murder?
Is it humane to continue life if a person is suffering
and in pain?
Is it humane to continue someone’s life who has no
chance for a reasonable life?
Is it humane to continue life if a person has no way
to consent to treatment?
Who decides?
16. Control Mechanism
• CO2 is a waste product
of the cells
• CO2 makes carbonic
acid in the blood
(changes pH)
• The medulla oblongata
keeps track of pH,
controls breathing
24. Alveoli (pl)
• Site of gas exchange
• We have ~ 300 million
• Surface area equivalent
to a tennis court!
• Capillaries surround
each alveolus.
25. How does it work?
• Lungs are not muscles
• Diaphragm is a muscle
– Diaphragm contracts
– Ribcage expands
– Lungs expand
– Air rushes in to fill up
empty space
26. How does it work?
• Exhaling is generally a
passive process
– Diaphragm relaxes
– Lungs compress
– Forces out air
• You can also use the
muscles around your
ribcage to constrict your
chest more, expelling
more air