Biopac Lesson 15 Flashcards
Exercise is _____; there is a progression of events that occur sequentially in response to the desire to increase the metabolism
Phasic
Exercise is really just an increase in the ____ ________ rate caused by an increase in ________ activity
Basal metabolic
Muscular
The first phase of exercise is called what? Where does it come from? How does it spread?
Anticipatory phase
Comes from cerebral cortex (usually frontal lobe) and spreads via thalamus to the sympathetic nervous system
Muscles need energy. Where does the energy from everyday living and light exercise come from?
Fatty acids
When the muscles demand more energy, the energy source changes from fatty acids to what?
Carbohydrates
Where does the carbohydrate needed for strenuous exercise come from?
Glycogen stored in muscles, liver, blood glucose
The energy needed for contraction comes via the ______ initially
Krebs cycle
As muscle demand increase, enzymes of the Krebs cycle become saturated. What does this cause?
Increase of pyruvic acid, the end product of glycolysis
Pyruvate is then converted to lactic acid
The Effects:
1) The anticipatory phase _______ heart rate & blood pressure by the release of _________.
Increases
Norepinephrine
The Effects:
2) Shift from fatty acid metabolism to carb metabolism and resulting lactic acid increase stimulates medullary respiratory centers to increase ______. The drop in pH also causes ________ to muscles producing the most lactic acids. This causes _______ blood flow to those areas, and increased oxygen. The increased oxygen:
Respiration
Vasodilation
Increased
Helps but does not stop the buildup of lactic acid and pyruvate
The Effects:
3) The increase in blood flow to the muscles causes an ______ in venous return, which activates the ______ reception in the heart/aorta/carotid arteries, and ______ heart rate (and therefore blood pressure.
Increase
Stretch
Increases
The Effects:
4) The lactic/pyruvate build-up plus an increase in ____________, affect the respiratory centers in the pons and medulla causing an _____ in breathing rate
Plasma CO2 levels
Increase
The Effects:
5) B/c muscles are only ____% efficient, most of the ATP breakdown is given off as _____, which then activates the hypothalamic brain centers to start ________ mechanisms such as:
25-30%
Heat
Cooling
Sweating, dilating blood vessels close to outer surface
The most prolonged mechanism to return to normal is the __________ and _________.
Removal of lactic acid
Respiration
As you exercise, your body temperature:
Lowers
