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4 Cards in this Set
- Front
- Back
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Short term response in arctic |
-shivering - vasoconstriction: narrowing of blood vessels by small muscles in their walls (reduces conduction) -countercurrent heat exchange: deep arteries are located adjacent to veins allowing transfer of heat between them- warms blood returning from surface -hunting response or cold induced vasodilation: after initial vasoconstriction and dilation of 5 minute intervals |
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Long term response for arctic |
Bergmann& allens rules: Bergman - higher mass relative to surface area from cold climates Allens- focused more on limbs
-increased BMR 20-40% higher - possibly due to diet but increased protection due to heat Generation during exposure ... Shiver less - reduction jn sympathetic nervous system (sns) response to cold : low shivering threshold, allows to sleep, gain weight in winter (sns or inactivity) - higher 60% core to shell conductance via high rate of peripheral blood flow to extremities
-Inuit : increase vasoconstriction capabilities - no evidence for lower facial relief -Siberia (evenly reindeer herders): slow growth rates in late childhood and adolescence, adequate food intake. Increased metabolic requirements associated with adaption to cold -Ama divers (Korean) : most extreme exposure to cold. Seasonal differences between none-diving women. Higher bmr, likely non shivering thermogenesis. Lower shivering threshold Europeans- fish fillet era and n. Sea fisherman |
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High altitude short response |
Becoming more efficient at 02 intake for delivery to body 1)increase respiration rate & depth (due to stimulation of carotid and aortic bodies... In peripheral blood vessels - in response to lower blood oxygen levels 2) respiratory alkalosis - increased loss of CO2 via correspondingly increased expiration production of carbonic acid resulting in increase of blood ph 3)decreased respiration - Cerebrospinal ph also increases resulting in stimulation of brain receptors that Lower respiration rate 4) Restore balance - over course of a few days, excretion of bicarbonate ions restores acid base balance and can increase respiratory rate
Other: O2 uptake/carrying capacity increases (increased red blood cell and hemoglobin production in addition to increased number of cells actual hemoglobin per cell also increases - oxygen delivery increases due to increased vascularization via increased capillary utilization with corresponding vasoconstriction - at level of tissues, more efficient use of O2 of switch to anaerobic cycle |
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Long term high altitude |
The longer period of adaption time the higher hemoglobin (protein molecule in red blood cells that carry O2) concentration Genetic: Himalayan: Normal birth weight babies with better O2 transport to fetus, smaller cheat capacity relative to Andeans suggest all around better hypoxic (hypoxia reduced concentration of O2) conditions Andes: possibly larger chest capacity, highlanders raised in lowlands Both: more efficient glucose metabolism for brain use
Developmental - larger chest/lung capacity -higher ventilation rate (even at low altitude) -work ability = to low land capabilities circle window before age of 8, highest at 5 - more efficient lung volume and function |
