Week 6 - Brain blood flow and exercise

Question 1

Blood flow to the brain

Answer 1

Vital for survival, Brain only 2-3% of body mass however requires 20% of cardiac output, Stroke will occur by over or under perfusion

Question 2

Functional consequences of brain blood flow

Answer 2

• Performance
• Cognitive function
• Impairment linked with disease/conditions
• Prognistic value

Question 3

Aerobic fitness and brain flow

Answer 3

Habitual exercise offsets the natural age-related decline in brain blood flow
Brain blood flow decreases as age increases due to inactivity

Question 4

Measurement of brain blood flow

Answer 4

MRI (structure and functional) Doppler, NIRS

Question 5

Transcranial doppler

Answer 5

Measures blood velocity as an index of flow

Question 6

Near infared spectroscopy

Answer 6

Measures the balance of oxygen supply and oxygen demand at a capilary level in cerebral cortex tissue
Gives a measure of brain activation - neurovascular coupling

Question 7

Brain blood flow responsiveness to CO2

Answer 7

Brain blood flow is highly sensitive to changes in arterial partial pressure of carbon dioxide
Even when perfusion pressure is increased

Question 8

What happens if you hold petco2 constant

Answer 8

Brain blood flow continues to rise as exercise intensity increases

Question 9

How does exercise in water impact brain blood flow

Answer 9

Exercise on water increases brain blood flow compared to on land.
In water, same increase from running on land to walking on land has same impact on increasing brain blood flow
Increased hydrostatic pressure = increased venous return