Differing Adaptation to High altitudes Flashcards
How long have Tibetans been at HA?
> 25,000 years
What are 6 characteristics of Tibetans respiratory features?
Bigger lungs
High TV
High FEV1/FVC
High diffusing capacity
higher ventilation
Less shunting
What are 5 oxygen carrying characteristics of Tibetans/
Low Hb conc
Low blood viscosity
Low SaO2
Same oxygen affinity
Low oxygen content per L
Has Tibetan Hb response system been due to genetic changes?
Yes - single nucleotide polymorphisms in PHD2 and HIF2 alpha gene
How did tibetans increase their blood volume?
Increased Hb and plasma volume - diluted Hb
How did andeans increase their blood volume?
Increased red cell component -> more viscous blood
How do Tibetans improve blood flow?
Increased NO metabolites -> vasodilation & systemic/pulmonary pressure is kept low
What are 7 cardiovascular adaptations that the Tibetans have compared to acclimatized lowlanders?
Low PA pressure
Low RVH
Elevated max. HR
Elevated CO
Increased muscle & cerebral blood flow
Increased NO metabolites
What are 6 skeletal muscle adaptations that the Tibetans undergo?
Increased type 1 fibres
Decreased fibre cross sectional area
Decreased mitochondrial volume density
increased myoglobin concentration
Increased capillary:fibre ratio
Increased carbohydrate oxidation
Did the Tibetans suffer from weight loss at high altitudes?
No
How do Tibetans increase O2 delivery?
Increasing CO & tissue blood flow
What is a indicator of high cardiac output in urine?
Elevated cGMP
How is TPR reduced in tibetans?
Produce higher NO metabolites
When is successful adaptation reached?
Successful reproduction at high altitude
