cardiovascular system Flashcards
vascular shunt
redirection of blood flow to area where it is most needed
vasodilation
widening of blood vessels
vasoconstriction
narrowing of blood vessels
anticipatory rise
An increase in heart rate caused by an increase in activity of the sympathetic nervous system causing the adrenal glands to release adrenaline into the blood stream.
sub-maximal exercise
any activity that doesn’t exceed 85% maximum heart rate, causes cardiac output to remain relatively unchanged.
diastole
the heart filling with blood when relaxing
systole
the heart emptying the blood when contracting
maximal exercise
- cardiac output increases significantly
- untrained individuals cardiac output is 14-20 L/min.
- trained individuals - 25-35 L/min
chemoreceptors
detects increases in carbon dioxide and lactic acid and decreases in oxygen
baroreceptors
detects an increase in blood pressure
proprioceptors
detects increase in muscle movement
haemoglobin
oxygen carrying red pigment found in red blood cells
parasympathetic
controls the bodies ‘rest’ functons
sympathetic
controls your bodies responses (fight/flight response)
autonomic
controls things you don’t have concious control over
blood pressure
force exerted by the blood against the walls of the blood vessels
dual action pump
two seperate pumps that work simulateneously to pump blood to two different places
bradycardia
decrease in resting HR to below 60bpm
cardiac output
the amount of blood pumped around the body per minute
cardiac output formula
heart rate x stroke volume
stroke volume
the amount of blood pumped around the body per beat
venous return
the return of blood to the right side of the heart via the vena cava
myogenic
generates it’s own electrical impulse
arterio-venous difference (avo2)
the difference in the content of oxygen in the arterial blood arriving at the muscle and the oxygen content of the venous blood leaving it
cardiovascular drift
- when the heart rate increases steadily even when the exercise is at the same intensity
- fluid is lost in sweat from the plasma volume-decreases venous return and stroke volume
- heart rate increases to maintain a high cardiac output.
BOHR shift
- a shift of the curve to the right caused by the increase in carbon dioxide in the blood
- results in an increase in concentration of hydrogen ions in the blood, lowering the pH
myoglobin
a red protein containing haem which carried and stored oxygen in muscle cells
hypertrophy
an increase in muscle density of the myocardium
the heart gets bigger and stronger
systemic circulation
- carries oxygenated blood from the heart to the body
- carries deoxygenated blood from the body to the heart
pulmonary circulation
- carries oxygenated blood from the lungs to the heart
- carries deoxygenated blood from the heart to the lungs
valves
- semi-lunar valves orevent backflow of blood
- the blood in the veins can only move towards the heart and cannot ball back to where it came from
respiratory pump
- muscles around the thoracic and abdominal regions cause changes in pressure - changes in pressure allow the veins in this region to compress, causing blood to be ‘sucked’ through them
skeletal pump
the muscles surrounding the veins expand and contract pressing on the veins and causing a pumping effect
starling’s law
- increase in venous return
- greater diastolic filling of the heart
- cardiac muscle is stretched (myocardium)
- more force of contraction
- increased blood ejected
- increased stroke volume
- cardiac output
