Human perf 2

Lowered into water, at 10m, vol of air halves so barrel that is lower to fill up Free dive from here Later connected to surface and air pumped in

Suit connected to surface with handsfree

CO2 build up underestimated pressures needed Cold exposure Falling over- air to feet

Self contained underwater breathing appliance. Now to 200atm/ 3000PSI Automatic demand valve to mouthpiece which regulates pressure in regards to depth

Very deep Must remain constant vol as if this decreases it will be very hard to increase again

760mmHg 760 Torr 100 kPa 1000 hPa 1 bar 1000 cmH20

For a fixed amount of gas at a constant temperature Volume x Pressure = constant Or P1 x V1 = P2 x V2 Hence deeper you go (higher pressure) the quicker the gas bottle will empty (lower vol)

6L down to 1.5 at 30m (4ata) would draw tissue fluid and burst BVs as lower pressure and result in drowning

Larger volume of lung (>6L) and hyperventilation/ overfilling Smaller residual volume - diaphragm rises higher

Static apnea Dynamic apneo Constant wight (no fins or fins)

The pressure exerted by a ags mixture is equal to the sum of the pressures which each of the gasses would exert if it alone occupied the space filled by the mixture (partial pressure)

.209 x 760 = 159mmHg

conc x 760 x ata (total pressure)

if the Partial pressure of a gas in a liquid is reduced then the amount of that gas which can be held in solution will be decreased proportionally

Normally rising CO2 triggers urge to breath. Hyperventilation prior decreases CO2 (doesnt really increase O2 as already nearly fully saturated) resulting in a delay breathing stimulus. If O2 falls below 30mmHg (normally 105) then blackout occurs All phases of the dive in shallow water so depressurisation is not a factor Can train yourself to be less sensitive to CO2 also by often breathing in high Co2. - more likely

Arterial O2 is normally 105mmHg At 4ATA it increases to 420. This can decrease to 105 without a problem. Sudden ascent then pressure will fall 3x. Result in <30mmHg and a blackout. Deeper more likely

Loss of motor control. It is a partial loss of physical or mental integrity and generally occurs up to 15 seconds after reaching the surface, normally during your first breath after a dive. Blackout is the next stage.

Adjusts pressure to match surrounding pressure so lung volume stays constant

Watertight container with an open bottom lowered to a waterbed to allow construction work. Kept pressurised to prevent water getting in

Itching The bends - joint adn back pain and hunched appearence The chokes - Lung caps and capillaries - suddenly loads of gas given off in lung The staggers - vestibular organ/ balance The cerebral bends - vision, higher functions, speech (fatal) Spinal cord - pins and needles, paralysis

Nitrogen partial pressure increases resulting in more nitrogen dissolved in the blood stream - approximately 1L per atm. As ascend then microbubbbles form in blood stream - can block capillaries (embolise) or occupy space causing deformity e.g. bone Can enduce a blood clot Air embolism if lung tissue ruptures Face mask squeeze - BVs Blockage of Eustachian tube - prevents equalising and can cause haemorrhage and rupture of tympanic Blockage of sinus opening - relative vaccum - haemorrage of sinus membrane and fain Mediastinal and SC emphysema Pneumothorax - expanding air pocket (keep mouth often on ascent) rupturing pleura

Fully exhale - collapsible alveoli, and sturcutres (not trachea), decrease blood flow to lungs

Re-compression if possible to treat. Decompression slowly - use charts. Haldane 1906 found that halving pressure (doubling volume) was acceptable. Navy decompression tables

% body fat - being female. If flying soon.