Dive PhysiologyDive Physiology

AndAnd

Medical AspectsMedical Aspects

Underwater PhysiologyUnderwater Physiology

RespirationRespiration

Effects of heat and coldEffects of heat and cold

BarotraumaBarotrauma

Pressure related problemsPressure related problems– DirectDirect– IndirectIndirect

RespirationRespiration

The breathing cycleThe breathing cycle

Oxygen consumptionOxygen consumption

Carbon dioxideCarbon dioxide

Breath holdingBreath holding

HypoxiaHypoxia

hypercapnia/hypocapniahypercapnia/hypocapnia

Carbon monoxide poisoningCarbon monoxide poisoning

RespirationRespiration

Air Must Pass Through“Dead” Spaces

Respiration

The ProcessMovement of air intoand out of the lungs

Transport of oxygento the cells and removalof carbon dioxide

Approx. 5% Oxygen Consumed

Carbon DioxideIncreases 5%

Shallow Water BlackoutCaused by ExcessiveHyperventilation

Skip Breathing CausesHypercapnia

Air with Less Than 10%O2 at 1atma Will NotSupport Consciousness

Mouth, Nose,Throat

Diaphragm

Lungs

Trachea

Bronchi

Bronchioles

Alveoli Heart

Lungs

Capillaries

Vena Cava

Aorta Pulmonary Artery

PulmonaryVein

CO2

O2 CO2

O2

Hemoglobin Molecules in Red Blood Cells Carry Oxygen

Effects of Heat and ColdEffects of Heat and Cold

Heat injuries (hyperthermia)Heat injuries (hyperthermia)– crampscramps– exhaustionexhaustion– strokestroke

Cold injuries (hypothermia)Cold injuries (hypothermia)– Decreased body functionsDecreased body functions– Decreased mental functionsDecreased mental functions– Shivering, numbnessShivering, numbness– Related protection requirementsRelated protection requirements

Temperature InjuriesTemperature Injuries

Temperature Injuries

Progressive Symptoms and Effects

Heat Cold- Cramps- Exhaustion- Stroke

Profuse SweatingWeaknessMalaiseDry, Flushed Skin

Cool VictimOral FluidsNo Caffeine/Alcohol

Sym

ptom

s

- Hypothermia

Uncontrolled ShiveringLoss of Coord/DexterityNumbness

Warm VictimNo CaffeineNo Alcohol

Sym

ptom

s

1st A

id

1st A

id

Pressure Related ProblemsPressure Related Problems(direct)(direct)

Descent (squeezes)Descent (squeezes)– EarsEars– SinusesSinuses– MaskMask– ThoracicThoracic– TeethTeeth– Stomach/IntestinesStomach/Intestines– SuitSuit

Ascent (expansion)Ascent (expansion)

– Air embolismAir embolism

– PneumothoraxPneumothorax

– Mediastinal Mediastinal EmphysemaEmphysema

– Subcutaneous Subcutaneous EmphysemaEmphysema

Pressure Related ProblemsPressure Related Problems(indirect)(indirect)

Decompression sicknessDecompression sickness– Nitrogen partial pressuresNitrogen partial pressures– SolubilitySolubility

Nitrogen narcosisNitrogen narcosis

Oxygen toxicityOxygen toxicity

Nitrogen narcosisNitrogen narcosis

Nitrogen Narcosis

“Rapture of the Deep” - “Martini’s Law”

SURFACE

75-100’

150-175’

200’+

Thinking andJudgmentPOTENTIALLY Affected

Communication,Motor and MentalTasks IMPAIRED

NOT IN CONTROL

Symptoms and Effects onIndividual Diver VaryWith Depth and Exposure.

Barotrauma

Direct PressureRelated Problems

Indirect PressureRelated Problems

- Descent (Compression) Squeezes

Ear, Sinus, Lung,Stomach, Intestinal,Tooth, Equipment

- Ascent (Expansion)

Lung Ruptures -Subcutaneous andMediastinal EmphysemaPneumothorax

Air Embolism

- Decompression Sickness (The Bends) (DCS)

- Nitrogen Narcosis

- Oxygen Toxicity

Descend and AscendSlowly to MinimizePotential Problems

NEVER HOLD YOURBREATH ON SCUBA!

Precautionary Decompression Stops(Safety Stops) HelpReduce Bubble Formationand Incidence of DCS

Physiology SummaryPhysiology Summary

Physiology Summary

Respiration is Mechanical- Oxygen-Carbon Dioxide Exchange- Slow Deep Breathing

Barotrauma - Pressure Injury- Direct Subcutaneous Emphysema Mediastinal Emphysema Pneumothorax Air Embolism- Indirect DCS (the Bends) Nitrogen Narcosis Oxygen Toxicity

Proper Exposure Protection isRequired to Avoid Hypothermia