cardiovascular system Flashcards
starting from the left atrium, explain the pathway of blood
left atrium, bicuspid valve, left ventricle, semi-luna valve, aorta, BODY, vena cava, right atrium, tricuspid valve, right ventricle, semi-luna valve, pulmonary artery, LUNGS, pulmonary vein, left atrium
how do you calculate cardiac output?
HR X SV
how to calculate stroke volume from end systole and diastole volume
EDV-ESV
what’s heart rate (HR) and its units
number of times your heart beats per minute, bpm
what’s stroke volume (SV) and its units
the volume of blood that you can eject from the left ventricle per beat, ml
what’s cardiac output (Q) and its units
the volume of blood that you can eject from the left ventricle per minute, L/min
what’s systole and diastole in simple terms?
systole- heart contracting
diastole- heart relaxing
what’s end-diastolic volume (EDV)?
the volume of blood in the ventricles at the end of the relaxation filling stage
what’s end-systolic volume (ESV)?
the volume of blood remaining in the ventricles at the end of the contraction phase
rest HR for an untrained athlete
60-72 bpm
sub max HR for an untrained athlete
100-130bpm
max HR for any athlete
220-age
rest HR for trained athlete
50bpm
sub-max HR for trained athlete
95-120bpm
rest SV for untrained athlete
70ml
sub-max SV for untrained athlete
100-120ml
max SV for untrained athlete
100-120ml
rest SV for trained athlete
100ml
sub-max SV for trained athlete
160-200ml
max SV for trained athletes
160-200ml
rest cardiac output for an untrained athlete
5 L/min
sub-max cardiac output for an untrained athlete
10-15 L/min
max cardiac output for an untrained athlete
20-30 L/min
rest cardiac output for a trained athlete
5 L/min
sub-max cardiac output for a trained athlete
15-20 L/min
max cardiac output for a trained athlete
30-40 L/min
what’s sub-maximal exercise?
low to moderate intensity within a performer’s aerobic capacity
what’s maximal exercise?
high intensity of exercise above a performers aerobic capacity which induces fatigue
what’s venous return and what’s dependant on it?
it’s the return of blood from the body to the right atrium.
stroke volume is dependant on it
what are the 5 mechanisms of venous return?
pocket valves, muscle pump, respiratory pump, smooth muscle, gravity
what are pocket valves?
one way valves that prevent back flow of blood and direct it to the heart
how does the muscle pump help venous return?
viens are situated between muscles, this helps to squeeze blood back towards the heart when the muscle contracts and relaxes
how does the respiratory pump help venous return?
during exercise, breathing becomes deeper and faster which causes pressure changes in the thorax and abdomen. this increases the pressure in the abdomen, squeezing the large veins in that area, helping force blood back to the heart
how does smooth muscle help venous return?
contraction and relation of smooth muscle in the middle layer of the vine walls also helps push blood through the veins towards the heart
how does gravity help venous return?
blood from the upper body is aided by gravity as it depends to the heart
what happens to stroke volume as intensity increases?
SV increases linearly with intensity up to 40-60% of max (sub-max intensity) due to the ventricle size and plateus
what’s starling’s law?
increased venous return leads to an increased stroke volume. this is due to an increased stretch of the ventricle walls and therefore a greater force of contraction
what are receptors?
sense organs that pick up stimuli, which are relayed to the brain (medulla oblongata)
what are the three types of receptors?
proprioreceptors
chemoreceptors
baroreceptors
what are proprioreceptors?
detect a change in movement
in muscles, tendons and joints
inform the CCC that motor activity has increased
what are chemoreceptors?
sensitive to chemical changes in muscle, aorta and carotid arteries. inform the CCC that lactic acid and CO2 levels have increased (decreased pH)
what are baroreceptors?
informs the CCC that blood pressure has changed
sensitive to stretch within the blood vessel walls
what’s the conduction system?
a set of structures in the cardiac muscle which create and transmit an electrical impulse, forcing the atria and ventricles to contract. there are 4 structures
what’s myogenic mean?
the capacity of the heart to produce its own electrical impulse, which causes the cardiac muscle to contract
what’s neural control?
receptors
whats hormonal control?
adrenaline
where is the CCC located?
medulla oblongata
what does the sympathetic nervous system do?
increase HR
to the cardiac accelerator nerve
what does the parasympathetic nervous system do?
decrease HR
to the vagus nerve
what does adrenaline directly stimulate?
the SA (sito-atrial node)
where’s the SA node located?
top of the right atrium
what happens after the impulse reaches the SA node?
impulse travels through atria walls causing wave like contractions, this causes both atria to contract and push blood into the ventricles
what happens at the AV node?
slight delay, to allow the atria to finish their contraction so valves can close
where is the AV node located?
right atrium
what happens to the impulse after the AV node?
impulse spreads down to the bundle of his and then spreads around the ventricle walls through a network of purkinje fibres.
where’s the bundle of his located?
in the septum
what are the 4 structures of the conduction system?
SA node, AV node, bundle of him, purkinje fibres
what are the two structures of the conduction system that undergo atrial systole?
SA node, AV node
what are the two structures of the conduction system that undergo ventricle systole?
bundle of his, purkinje fibres
what happens to intrinsic control during exercise?
temperature increases, speeds up nerve transmissions which increases HR. this will effect the viscosity of the blood.
venous return increases, increases the stretch of the ventricle walls, increases the force of contraction, increases EDV therefore SV
what happens to intrinsic control after exercise?
temperature decreases, HR decreases
venous return decreases which decreases SV (starling’s law)
whats the process of the vascular shunt mechanism?
receptors to VCC (vasomotor control centre) to the nervous system to arterioles to capillary beds to the sympathetic nervous system
where is the vasomotor control centre (VCC) located?
in the medulla oblongata
in the vascular shunt mechanism, what happens in the capillary beds?
blood flow is controlled by pre-capillary sphincters which are at the entrance. this stimulates the sympathetic nervous system
in the vascular shunt mechanism, what does the sympathetic nervous system do?
either vasodilate or vasoconstrict the pre-capillary sphincters and arterioles supplying muscles and organs
what is blood flow like during rest and during exercise to the working muscles and other organs?
at rest: 80-85% other organs, 15-20% to working muscles
other way around during exercise
how is oxygen transported in the body (2 ways)?
97% is carried within the protein haemoglobin to form oxyhaemoglobin, 3% of oxygen is carried within blood plasma.
how is carbon dioxide transported in the body (three ways)?
70% combines with water within red blood cells as carbonic acid
23% combines with haemoglobin to form carbaminohaemoglobin
7% is dissolved in blood plasma
Explain how the conduction system of the heart controls diastole
- (Atria relax) Atria/ventricles do not contract
or atria/ventricles relax
or atria/ventricles are filling/fill with blood - (No impulse) (due to …) No (electrical) impulse/signal
