Hapter 4 Flashcards
Acute response
Something that happens in the body straight away
3 types of Acute Responses to exercise
Cardiovascular
Respiratory
Muscular
What is the response dependent on?
Intensity and length of exercise
Aim of response
1- Get more O2 in (respiratory)
2- Deliver it quicker (cardiovascular)
3- Use it more effectively (muscular)
Acute respiratory responses to exercise
Ventilation
Tidal Volume
Respiration Rate
Ventilation
(how much air is breathed in or out in one minute)
V (litres per minute) = TV (litres) × RR (breaths per minute)
- Increases during exercise as Tidal Volumne and Respiratory Rate both Increase
- Plateus after 4 or 5 minutes during submaximal exercise
- During maximal intensity, ventiliation continues to increase unitll the exercise is stopped.
tidal volume (TV)
(how much air is inspired or expired in one breath
- Exercise will increase depth of breathing thus more air per breath
- Will plateau/ or slightly down at max effort
respiratory rate (RR)
(the number of breaths taken in one minute)
- Increases during exercise to get more air into the lungs
Diffusion
Exchange of gas between the alveoli(airsacs in the lungs) to capillaries (blood vessels) in the lungs
Diffusion - gas moves from high to low concentration
In Alveoli - O2 High, Co2 is low
In Capillaries - O2 low, CO2 is high
- Diffusion allows O2 to move from lungs to blood and CO2 from blood to lungs
Cardiovascular responses to exercise
cardiac output (Q) stroke volume (SV) heart rate (HR)
Heart Rate
(Amount of beat p/m)
- Increases linearly as exercise intensity increases
- WIll increase until oxygen demands have been met, then level off, as the body has reached steady state. With increasing workloads, heart rate will increase linearly until max HR is met.
Stroke Volume
(Amount of blood ejected by heart per beat)
- Increases as exercise intensity increases but reaches peak before maximal intensity
Cardiac Output
(Amount of Blood ejected by heart per beat)
- HR x SV = CQ
- Increase during exercise as both HR and Stroke Volume increase
- As exercise reaches maximum HR will be close to its maximum although Stroke Volume will decrease
Blood Volume
(Consists of RBCs, WBCs, Plasma and Platelets)
- Decreases during exercise due to loss of plasma via sweat
- Amount determined by intensity and environment
Blood pressure
(Pressure in arteries when heart beats or relaxes)
systolic blood pressure - pressure in arteries as heart beats
Diastolic Blood Pressure - pressure in arteries as heart relaxes
Increased Cardiac Output = Increased Blood Pressure
Venous Return
When muscles contract, veins are constricted forcing blood back to the heart
- During exercise venous return increases due to greater muscle contraction
Redistribution of Blood Flow
Blood vessels open up (vasodialation) to allow blood to flow through muscles
- Blood vessels can also close up (vasoconstriction) to restrict blood flow to other areas where it is not needed
AVO2 Difference
Difference in oxygen concentration in the arterioles compared with the venuoles
- During exercise, the muscles uses up more o2 so less O2 will be in the veins
- Exercise requires more O2 to be used by the muscle, so the diff is greater
Acute Muscular Responses to exercise
Increased blood flow Motor unit recruitment Energy substrates Lactate Body temperature
Increased blood flow
During exercise, blood is directed away from non-essential organs to the working muscles.
-During exercise, skeletal capillaries open up and serve three main purposes. These are to:
• allow for increases in total muscle blood fl ow
• deliver large blood volume with minimal increase in blood fl ow velocity
• increase the surface area to increase diffusion rates.
-This results in an increase in blood flow to the working muscles, allowing for greater delivery of oxygen to meet the metabolic demands of the exercise.