The Cadriovascular System Flashcards
health
complete physical, mental and social well-being, not merely the absence of disease and infirmity
fitness
the ability to meet the demands of the enviroment
stroke volume
the volume of blood pumped ot of the ventricles during each contraction
cardiac output
the volume of blood pumped out of the ventricles per minute
(HR x stroke volume)
sympathetic nervous system
part of the ANS and can activate an increase in HR
parasympathetic nervous system
part of the ANS and can activate a decrease in HR
vascular shunting
the redistribution of blood flow around the body
myogenic
the hearts ability to create its own contraction
chemoreceptors
repsonsible for detecting a change in co2, lactic acid, blood acidity
baroreceptors
responsible for detecting a change in blood pressure
proprioceptors
repsonsible for detecting change in muscle movement
plasma
the liquid part of blood
myoglobin
an oxygen binding protein found in muscle tissue
haemoglobin
an oxygen binding protein found in red blood cells
oxyhaemoglobin
found when oxygen combines with haemoglobin
mitochondria
the part of the cell where repsiration and energy production occur
disassociation curve
a graphical representation of the rate at which oxygen seperates from haemoglobin and diffuses into the muscle cells
bohr shift
the shift to the right that the disassociation curve makes during exercise
venous return
the flow of the blood back to the heart via the veins and spersifically the vena cava
starlings law
stroke volume increases due to an increase in venous return
cardiovascular drift
the increase of heart rate during when taking part in steady exercise in a warm enviroment
arterio-venous oxygen difference
the difference between the pressure of the oxygen in the arteries and veins
what is maximal exercise
- when excerising at maximal level, a preformers stroke volume will only continue to rise up to 60% mamimal effort
- at this point the heart rate is too high for the ventricles to have enough time to fill up with blood, meaning that there is a plateau in stroke volume
anticipatory rise
this is an increase in heart rate that occurs just before taking part in exercise, it is caused by an increase in activity from the sympathetic nervous system
hormonal regulation
relating or contaning hormones
neural regulation
relating to nervous system
chemical
relating to reponses where chemicals are released in the body
adrenaline
a hormone which leads to an increase in heart rate, blood pressure and awarness
vasodilation
blood vessels dilate (get bigger) - allows more blood for te active muscles
vasoconstriction
blood vessels constrict (get smaller) - takes blood away from inactive areas and the organs
how is vascodilation used by the body during exercise
occurs i arteries delivering oxygenated blood to preformers leg, this allows more oxygen to be delivered to active musckes allowing more aeorbic repsiration to take place to produce more enrgy
how is vasocontriction
arteries deliver blood to areas such as digestive system and liver are constricted, this diverts a large preportion of the performers blood supply to their muscles
what is the process of vascular shunting
- increase in co2 and lactic acid detected by the chemoreceptors
- the chemoreceptors stimulate the vasomotor
- the vasomotor signals for a redistribution of blood flow
- vasodilation and vasocontriction occur and the pre-capillary sphincters adjust blood flow into the capillaries
vasomotor
- located in medulla oblongata
- regulates heart rate, blood pressure and redistribution of blood flow
deffninition of cardiac conduction system
a group of cells found in the wall of the heart which are responsible for the electrical impulses that cause the heart to contract
cardiac conduction system order of events
- electrical signal begins in the sinoatrial node (SAN)
- the electrical impulses travel through the atria, causing them to contract and pass blood into the ventricles, before reaching the atrioventricular node (AVN)
- a delay of 0.1 seconds then occurs whilst the atria fully contract
- the electrical impulse then travels down the bundle of his, which is located in the septum
- the bundle of his then seperates into smaller branches called purkinke fibres, these spread around the ventricles and cause them to contract
in venous return how does the skeletal uscle pump help
muscles contracting and relaxinfg are constantly changing shape. this results in muscles pressing on nearby veins, this causes a pumping action, which pushes back towards the heart
in venous return how does the respiratory pump help
breathing in and out causes contracting many muslces, as welll as the diaphragm. This causes a constant change in the veins of the thoracic (chest) cavity, compressing the veins and causing venous return
in venous retuen how does the pocket valves help
veins are full of pocket valves, as blood passes throgh these valves, they close to prevent the backflow of blood
what is the process of starlings law
- there is an increase in venous return
- therefore greater diastolic filing of the heart occurs
- this causes the cardiac muscle to be stretched
- resulting in a more powerful contraction
- and an increased ejection fraction (stroke volume)
systolic blood pressure
the maximum blood pressure during contracton of te ventricles
diastolic blood pressure
the pressure of the blood in the heart as it relaxes and refills
