When exercising, the body redistributes blood so more to the working muscles and less to organs
This occurs by the constriction and dilation of the internal diameter of arteries
Inactive areas (organs) vasoconstrict
Active (working muscles) vasodilate
As O₂ and lactic acid increase in sport
Blood vessels dilate to allow more O₂
The intensity of exercise impacts the degree of vasodilation and vasoconstriction, from low intensity to high intensity
The cardiac cycle
1. Heart relaxes to fill with blood = diastolic phase
2. Heart contracts, forcing blood through the body and out = systolic phase
Stroke volume
The amount of blood pumped out per beat (ml/beat)
Stroke volume x heart rate
Cardiac output (blood pumped out per minute)
Heart rate
Number of beats generated per minute (bpm)
Healthy heart
Lower resting heart rate = more efficient
Unhealthy heart
Higher resting heart rate = weaker, goes into atrophy
The heart is mainly made of cardiac muscle which allows it to conduct its own electrical signal for contractions (doesn't need nervous stimulation)</b>
Electrical impulse in the heart
1. Spreads to both atria, causing contraction
2. Delayed from spreading to the ventricles so they aren't full of blood
3. Both ventricles then contract, forcing blood around the body
Arteries carry deoxygenated blood away, but the pulmonary artery carries deoxygenated blood and the pulmonary vein carries oxygenated blood
Valves
Prevent the backflow of blood as pressure in veins is lower
Blood pressure
The force exerted on artery walls by the blood
Systolic pressure: max pressure in arteries when the heart contracts
Diastolic pressure: pressure of blood during relaxation between heart beats (depends on the elasticity of arteries)
Plasma
Ensures O₂ transportation and CO₂ dissolves
Platelets
Stick together and clot to prevent blood loss and infection. Rush to site, swell, stick
White blood cells
Protect from disease, digest pathogens, and produce antibodies for protection
Healthy people have a lower RHR as their hearts are more efficient
Unhealthy people have a higher RHR as their hearts are weaker and can go into atrophy
Atrophy is when a muscle isnt used enough so weakens
Cardiac output is the amount of blood pumped out per minute
Diastolic phase is when the heart relaxes to fill with blood
The systolic phase is when the heart contracts forcing blood throught the body and out of the heart
The cardiac cycle is the electrical and mechanical events in the hearts complete cycle
Average RHR is 72bpm
Heartbeats are instrinsic as they are electrical signals that come from withing itself and dont need nervous stimulation
After the electrical impulse it spreads to both atria causjng contraction
The impulse is delayed from spreading to the venteicla so it isnt full of blood
Valves prevent the backflow of blood bc pressure in veins is lower
In sport, vasodilation because bloodflow is increased and temp increases
Respiration is to:
get O2 in the body
to remove CO2
to work with the cardiovascular system in sport to supply O2 and to function
Inhalation- intercostal muscles contract, ribcage moves up and out, diaphragm relaxes