SPEX 203 Flashcards
Length tension velocity relationship
If velocity is high, force is low
power
work/ time
Type 1 fibres
slow twitch, flatigue resistant
Type 2 fibres
fast twitch, flatigue quickly
Why are children less strong than adults
Same muscle quality but less muscle mass
sarcopenia
active loss of muscle
What motor units are recruited first?
The smallest ones (size principle)
When is muscle power maximised?
At moverate force and velocity
Flatigue
Reduction in strength
“The Central Governor model predicts that performance during the marathon [endurance events] is set by the subconscious brain
specifically to ensure that the athlete reaches the finish line whilst still in physiological homeostasis”, what priciple does this show?
Anticipatory Behavioral regulation
Ergometry
The measurement of mechanical energy production
Ergometer
A device from which work & power can be determined
Strength
The maximum force that a muscle group can produce in a single movement
Work equation
force x displacement
Force equation
mass x acceleration
Power
Rate of doing work
Endurance
ability to maintain force or repeated movements
Respiration
Aerobic metabolism
hyperpnoea
increased ventilation
2 main functions of respiratory system
to oxygenate blood and eleiminate carbon dioxide
Is inspiration active or passive?
active
Is expiration active or passive?
passive
Tidal volume equation
Tidal volume = aviolar volume + dead space volume
Aviolar ventilation is controled by what 4 aspects of inspiration?
Duration, force, frequency, and resistance
Where are the inspiratory neurons?
In the medial medulla, next to the expiratory neurons
How does increased ventilation help with posture?
It stiffens the trunk/ thorax
Extent of gas dissolving into a fluid depends on?
Pressure, Solubility, Temperature and Time
Key stages in O2 and CO2 exchange between atmosphere and blood
Aviolar ventilation and Aviolar blood transfer
What increases first tidal volume or tidal frequency?
Tidal volume
What is important for buffering H+ in excersise?
The lungs and Bicarbonate (HCO3)
What are the two parts of the cardiorespiratory systems and their functions?
Systemic= deoxygenisation
Pulmonary= reoxygenisation
Types of blood vessels?
Arteries, arteriols, cappillaries, venules, veins
VO2 equation
VO2 = Stroke volume x Heart rate x a-VO2 difference
Aerobic power & fitness depends on ability to… (four things)
- increase cardiac output (SV and HR)
- carry arterial oxygen
- redistribute blood flow to active muscles
- extract oxygen from blood in those muscles.
What is the hearts main fuel at rest?
Fatty acids
What is the hearts main fuel during hard excersise?
Lactate
What does a lower resting HR indicate?
Less cardiac O2 demand and higher potential for power
Intrinsic regulator of Stroke Volume?
Starling law of heart
Extrinsic regulators of HR? (3)
- Nural drive
- Hormones (from adrenal medulla or SNS)
- Temperature (7 beats per degree)
