Chapter 4 - Acute Responses to Exercise Flashcards
Define: Blood Volume
> Blood volume is composed of red blood cells and blood plasma circulating throughout your body. While red blood cells transport oxygen, blood plasma is a yellowish liquid that carries your red blood cells. Composed mostly of water, blood plasma contains dissolved proteins, hormones and minerals. Increased blood volume provides greater amounts of blood to your heart and increases how much blood your heart pumps per beat and per minute.
Blood volume is the volume of blood (both red blood cells and plasma) in the circulatory system of any individual.
TOTAL QUANTITY OF BLOOD IN THE BODY = PLASMA VOLUME + RED BLOOD CELL VOLUME
(plasma = fluid portion of the blood/yellowish liquid that carries your red blood cells)
(red blood cell volume = oxygen and co2 carriers - contain haemoglobin which carries oxygen).
Define: Diffusion
> The movement of molecules/ Diffusion of gases from an area of high concentration to an area of low concentration.
Diffusion capacity is increased during exercise, due to the increased surface area of alveoli and the muscle tissue.
This means that greater amounts of o2 and co2 can be exchanged at the alveoli (lungs) and at the muscles.
This allows for greater amounts of oxygen to be available at the muscles and greater amounts of co2 to be removed.
Define: Pulmonary (lungs) Diffusion
> Oxygen concentration is high in the lungs, so the oxygen is diffused from the alveoli into the bloodstream.
Carbon dioxide levels are high in the blood, so co2 is moved from the blood into the alveoli via a diffusion path.
Define: Muscle Diffusion
> Blood oxygen levels are high and muscle oxygen levels are low, so:
Oxygen is diffused into the muscle
Carbon dioxide is moved out of the muscle and into the bloodstream.
Define: Stroke Volume ; What happens during exercise?
> Amount of blood ejected by the left ventricle per beat.
Increases during exercise until it reaches its maximum at submaximal level, then any increases in Cardiac Output are due to Heart Rate.
Define: Heart Rate ; What happens during exercise?
> Number of times the heart beats per minute.
Lower in trained athletes (heart does not have to beat as much due to increased SV - the same amount of blood can be pumped with less beats).
Increases during exercise
> During submax, HR increases until the oxygen demands of the exercise have been met, then it levels off at steady state.
> During max (/with increasing workloads), HR increases linearly with intensity until max HR is reacher
Define: Cardiac Output
> Amount of blood pumped out of the heart per minute.
> Q = HR x SV
Define: A-vO2 Difference ; What happens during exercise?
> The difference in oxygen concentration in the arterioles compared with the venuoles.
The amount of oxygen extracted from the blood by the muscles.
Think of the sponge.
During exercise, the working muscles extract greater amounts of oxygen from the blood, increasing the a-vO2 difference.
Define: Oxygen Consumption ; What happens during exercise?
> The volume of oxygen that can be taken up and used by the body.
During exercise, as intensity increases so does oxygen consumption - a direct result of increased Cardiac Output and a-vO2 diff.
Define: Lactate Inflection Point (LIP)
> The last point where lactate entry and removal from the blood are balanced.
Lactate production increases in direct proportion to increases in work-rate. However, blood lactate concentrations remain relatively stable during sub-maximal work-rates, as the body is able to remove it at a similar rate to its production.
