Cardiovascular System Flashcards
what makes up the CVS
blood vessels and heart
list 4 materials that the blood transports round the body
oxygen and CO2 to and away from respiring cells
digested food from digestive system to liver (processing or storage)
urea from liver to kidneys
hormones and antibodies
what is another important function of the blood?
Distributing heat
What is diastole?
When the ventricle muscle is relaxed
what is systole?
When the ventricle muscle is contract
Describe the muscle of the myocardium
has small interconnected cells which allow rapid spread of impulses which cause contractions of the heart
Where does the impulse fro the contraction of the heart originate?
in the sinoatrial node, high in the right atrium
describe a full contraction of the myocardium
muscles of atrium contract and push blood into ventricle ventricles contract (starting at the base) and pump out blood at high pressure
What are the measurable parameters of the CVS and their normal resting values?
HR - 72 per minute
SV - 0.07 litres
CO - 72 x 0.07 = 5 litres per minute
BP - 120 systolic, 80 diastolic
Why do changes to the CVS occur during excersise?
There is a higher demand for oxygen because there is increased respiration in the skeletal muscles.
Describe changes to CVS and its parameters during exercise.
HR and CO increase. Atria receive more blood back therefore become distended which causes their force and amount of blood to ventricles to increase. Ventricles receive more blood so SV increases. Systolic blood pressure increases because distension of ventricles increases their force of contraction.
More changes to CVS
blood flow increases due to vasodilation,
increased blood flow through coronary arteries to keep heart muscles aerobic,
blood flow to gut and kidneys is decreased with vasoconstriction,
blood flow to skin increases by vasodilation and increases heat radiation
Describe differences between arteries and veins.
Artery wall has a thick layer of muscle and extra elastic layers.
Vein wall has a thin layer of muscle and includes valves to prevent blood flowing back.
Define recovery time
The period of time it takes for the CVS parameters to return to normal after exercise.
What happens to the by products of exercise during recovery time?
they are removed from muscle and enter the bloodstream for transport to kidneys, liver or lungs for processing or removal.
