The document discusses various aspects of life support and the respiratory system. It addresses how long humans can survive without eating, drinking, breathing, or their heart beating. It then explores methods of life support like feeding tubes, oxygen masks, and ventilators. The document considers whether withdrawing life support constitutes murder and debates who should decide on life support measures. It provides an overview of the respiratory system and its functions before examining specific organs and gas exchange processes.

1. Life support

2. How long can you live without...
• Eating?
• Drinking?
• Breathing?
• Your heart beating?

3. How long can you live without...
• Eating? ~4 – 6 weeks
• Drinking? ~ 3 days
• Breathing? ~4 – 5 minutes
• Your heart beating? ~about 4 minutes

4. How can we support life?

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?

10. Positives and Negatives
What benefit to the individual or society?
What costs to individual or society?

11. Martha Mason of Lattimore, North Carolina died on
May 4, 2009, after spending 60 of her 72 years in an
iron lung.

12. Coma Miracle

13. Premature Baby’s First Few Minutes

14. Respiratory System

15. Function
• To exchange gases with the surrounding environment
O2 in CO2 out

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

17. Organ Overview
• Mouth, Nose
• Epiglottis (stops foood
entering trachea)
• Trachea (wind pipe)
• Bronchus (branch)
• Bronchioles (little branches)
• Alveoli

18. Nose and Mouth
• Humidifies and warms air

19. Lung Protection
• Mucous –sticky to trap dirt
and bacteria
• Cilia (little hairs) to
– Filter dirt/bacteria
– Remove dirt/bacteria
with their wave action

20. Epiglottis
• Flap of cartilage
• Covers trachea
when eating
to prevent food
from entering

21. Trachea
• A large tube
supported from
collapse by rings of
cartilage.

22. Bronchi
• two, one going to each lung
• similar structure to the
trachea with cartilage rings

23. Respiration 3D

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

27. Diffusion
• Gases move from high
concentration to low
concentration.

28. Diffusion

29. When good lungs go bad...
Bronchitis – narrowed bronchioles
Emphysema – alveoli walls broken down

30. Pneumonia

31. Intubation

32. Cardiopulmonary Respiration