1

BLOOD GAS BLOOD GAS TRANSPORTTRANSPORT

PART 2PART 2

Instructor Terry WisethInstructor Terry Wiseth

2

PHYSIOLOGY OF PHYSIOLOGY OF DIVINGDIVING

3

Aquatic mammals can spend up to 10 minutes under water without breathingex: whales, seals, dolpins etc

Trained free divers (human) can spend a minute or more under water without breathing

PHYSIOLOGY OF DIVINGPHYSIOLOGY OF DIVING

4

PHYSIOLOGY OF DIVINGPHYSIOLOGY OF DIVINGNeeds of O2 for metabolism is provided by:

O2 stored in lungsO2 bound to HbMyoglobinDissolved O2 in body fluids

5

PHYSIOLOGY OF DIVINGPHYSIOLOGY OF DIVINGLargest physiological problem in diving

is maintaining heart and brain function

6

PHYSIOLOGY OF DIVINGPHYSIOLOGY OF DIVINGDiving reflexDiving reflex

Cardiovascular response to immersion of the head in waterSlowing of the heart rate by several beats per minute

More profound if the water is cold

7

PHYSIOLOGY OF DIVINGPHYSIOLOGY OF DIVINGCombines with peripheral

vasoconstriction and reduced metabolism induced by hypothermiaIncreases the chances of survival

for drowning victims in cold water

8

PHYSIOLOGY OF DIVINGPHYSIOLOGY OF DIVINGAquatic animalsAquatic animals

Reflexive bradycardia and peripheral vasoconstriction

Effect is to force skeletal muscle to draw on its store of O2 in myoglobin and then shift to anaerobic glycolysis

9

PHYSIOLOGY OF DIVINGPHYSIOLOGY OF DIVINGVarious marine mammals have been

found to have adapted special abilities which help in their respiratory processes, enabling them to remain down at great depths for long periods of time

10

PHYSIOLOGY OF DIVINGPHYSIOLOGY OF DIVINGThe Weddell seal only stores 5% of its

oxygen in its lungs, and keeps the remaining 70% of its oxygen circulating throughout the blood stream

Humans are only able to keep a small 51% of their oxygen circulating throughout the blood stream, while 36% of the oxygen is stored in the lungs

11

PHYSIOLOGY OF DIVINGPHYSIOLOGY OF DIVINGThe explanation for this is that the

Weddell seal has approximately twice the volume of blood per kilogram as humans

As well, the Weddell seal's spleen has the ability to store up to 24L of blood

12

PHYSIOLOGY OF DIVINGPHYSIOLOGY OF DIVINGIt is believed that when the seal

dives the spleen contracts causing the stored oxygen enriched blood to enter the blood stream

13

PHYSIOLOGY OF DIVINGPHYSIOLOGY OF DIVINGAlso, these seals have a higher

concentration of a certain protein found within the muscles known as myoglobin, which stores oxygen

The Weddell seal contains 25% of its oxygen in the muscles, while humans only keep about 12% of their oxygen within the muscles

14

PHYSIOLOGY OF DIVINGPHYSIOLOGY OF DIVINGNot only does the Weddell seal store

oxygen for long dives, but they consume it wisely as well

A diving reflex slows the pulse, and an overall reduction in oxygen consumption occurs due to this reduced heart rate

15

PHYSIOLOGY OF DIVINGPHYSIOLOGY OF DIVINGRegulatory mechanisms reroute blood

to where it is needed most (brain, spinal cord, eyes, adrenal glands, and in some cases placenta) by constricting blood flow where it is not needed (mainly in the digestive system)

16

PHYSIOLOGY OF DIVINGPHYSIOLOGY OF DIVINGBlood flow is restricted to muscles

during long dives and they rely on oxygen stored in their myoglobin and make their ATP from fermentation rather then from respiration

17

PHYSIOLOGY OF DIVINGPHYSIOLOGY OF DIVINGscuba diversscuba divers

If working at depths greater than 30 meters a diver breathes air at higher than atmospheric pressure and can accumulate dissolved gases in blood and tissues

18

PHYSIOLOGY OF DIVINGPHYSIOLOGY OF DIVINGIf diver’s return to the surface is too

rapid the dissolved gas comes out of solution forming bubbles in tissues and blood vessels (mainly N2) “bends”“bends”

Condition is prevented by controlled decompression

19

SCUBA DIVERSCUBA DIVER

20

Diving animals exhale exhale at the start of a dive

Increased pressure of diving to considerable depths decreases the volumes of gases in the lungs to the point of causing the lungs to collapse

PHYSIOLOGY OF DIVINGPHYSIOLOGY OF DIVING

21

Reduced air volume in lungs where gases are exposed to capillaries minimizes the transfer of dissolved N2 to the animal’s blood

Bubble formation is not a problem when the animal returns to the surface

PHYSIOLOGY OF DIVINGPHYSIOLOGY OF DIVING

22

ENDENDBLOOD GAS TRANSPORTBLOOD GAS TRANSPORT

PART 2PART 2