brain blood flow during exercise - week 6 Flashcards
what are the functional consequences of bad blood flow to the brain?
performance
cognitive function
impairment linked w diseases/conditions e.g. dementia
prognostic value
what are differences in trained and untrained people in terms of BBF decline ?
trained people have more blood flow than untrained people
blood flow still declines but offset decline when trained
what is transcranial doppler ?
measures blood velocity as an index of flow
shows beat tot beat BF
what is near infrared spectroscopy (NIRS)? (3)
measures balance of oxygen supply and oxygen demand directly at capillary level in cerebral cortical tissue
gives measure of brain activation
looks at oxygen/deoxy haemoglobin
what are the chemical changes during exercise to BBF?
decrease in PO2 and increases in PCO2 due to gas changes and breathing
what happens to BBF during exercise in terms of perfusion pressure ?
prevents hypotensive injury
increases during exercise
what causes fainting after exercise ? (4)
patrons would fall post exercise
drops BP
reduces BBF
leads to fainting
what are the main factors that interact with cerebral blood flow ? (5)
baroreflex
cardiac output
metabolism
symp/parasyp NS
arterial BP
what is the BBF responsiveness to CO2?
BBF sensitive to changes in arterial partial pressure of CO2
CO2 build up makes us breath again to exchange - can lead to hyperventilation
how does exercise intensity lead to reduced brain blood flow (4)
high intensity exercise increases anaerobic activity
this stimulates the respiratory system (increased)
there’s an increased in CO2
which leads to decreased brain blood flow
what happens to BBF when you clamp PCO2?
there is increased blood flow to brain even in high intensity exercise
but max power decreases despite higher BBF
what is the main modality that BBF is studied ? is this a problem ?
mostly used on stationary exercise bike - easier to measure someone stationary
can’t generalise research onto different sports/exercise
what did research on rowing tell us about BBF?
rowing has more challenges regulating BBF
shows exercise modality can effect BBF
what did comparison against running and cycling on BBF reveal ?
BBF is dependent on fitness and modality dependent
what has research on aquatic treadmill exercise shown ?
BBF is increased in water compared to on land
good for those disadvantaged such as had stroke as its harder for them to train at high intensity
water treadmills can improve CV health
due to increased hydrostatic pressure - increased venous return
