adaptations causing changes in body physiology Flashcards
19: VO2max
maximum amount of O2 delivered to working tissues and utilised in aerobic metabolism
19: increased exercise =
generates increase O2
increase VO2
19: utilisation theory
VO2 max is determined by body’s ability to utilise the available o2
19: result of increases ventilation is
increased diffusion capacity due to increased blood flow through lungs and tissue
19: VT
= point during exercise at which venilation increases at faster rate than VO2
19: cardiac output during exercise
HR increases
stroke volume increases
cardiac output increases
19: cardiac output equation
HR X SV
19: cardiac output
measure of blood flow per minute
19: what is HR increase mediated by
- increased sympathetic activation of SA node
- decreased parasympathetic output
19: stroke volume dips at
extremes of exercise
19: increased end diastolic volume from (preload)
sympathetic venocontriction
skeletal muscle pump
respiratory pump
19: decreased after load from
vasodilation
19: decreased sympathetic drive =
slower HR
19: what are changes in cardiac output dependent on
HR
stroke volume
19: factors affecting a-vO2 difference
increases capillaristaion,capillary fibre ratio and aerobic capability
19: adaptations of O2 transport - how are central adaptations achieved
low intensity training
7-% VO2 max
19: adaptations of 02 transport - how are peripheral adaptations achieved
higher intensity training
90% vo2 max
19: effects of detraining
initial decrease in VO2 max due to decreased SV
later decreased VO2 max due to decreased a-v o2 difference
20: partial pressure of given gas determined by
conc of gas within mixture
total pressure of mixture
20: as altitude increases what decreases
barometri pressure falls (hypobaria)
partial pressure of o2 drops
20: partial pressure - daltons law
pressure exerted by a mixture of gases is equal to sum of partial pressures of each gas in the mixture
20: response to hypobaric environment (low atmospheric pressure)
increase ventilation
chemoreceptors in carotid body stimulated by PO2 which drives respiration (due to hypoxia)
20: PiO2 + PaO2
PiO2 = partial pressure of inspired o2 PaO2 = partial pressure of arterial o2
20: oxyhemoglobin disassociation curve - left shift vs right shift
L - decreases temp / increased - R
L - decreased 2-2 DPG / increased - R
L - decreased H+ / increased - R
R - redcued affintiy
20: initial physiological adaptations to altitude - increased diphosphoglycerate (2-3 DPG)
- production increased
- o2 dissociation curve = right
- Hb released O2 at higher PO2 making O2 more available
20: where is 2-3 DPG produced
erythrocytes
20: long term physiological adaptations to altitude - increased haematocrit (Initial and long term)
I - decrease in plasma volume
I - increased urination and ventilation rate
L - increased haemopoiesis
L - decrease O2 tension in kidney so it released erythropoietin
20: long term physiological adpatations to altitude - increased capillary numbers
more capillaries - angiogenesis (formation of new blood vessels)
improved diffusion of O2
increased SA for gas exchange
20: AMS
acute mountain sickness = impact of hypoxia (low 02 levels) on body
20: AMS - symptoms
headache
fatigue
anorexia
20: HACE
AMS can progress to High altitude cereberal Edma
permanent neurologic disability
severe symptoms - Coma, seizures
20: HACE - vasogenic oedema
movement of fluid into CNS across brain barrier increases intracranial pressure
- impaired brain function or cerebral hypoxia
20: HACE - cytotoxic oedema
retention of fluid by cells in CNS, which increases intracranial pressure
- impaired brain function
- cerebral hypoxia
