Cardiovascular System Flashcards
(47 cards)
First heart sound
Closing of the AV valves. First mitral than tricuspid.
Systole
Events associated with ventricular contraction and ejection, short part of the cardiac cycle.
Diastole
Events associated with ventricular relaxation and filling, long part of the cardiac cycle.
Chronotropic
That influence the heart rate.
Dromotropic
Affect the conduction speed in the AV node, therefore the rate of electrical impulse on of the heart.
Inotropic
Affect the force/energy of the contraction of the heart.
Vagal / parasympathetic activation of the heart
Decrease chronotropy, decrease dromotropy and decrease inotropy by releasing acetylcholine.
Sympathetic activation of the heart
Increase in chronotropy, increase in dromotropy, increase in inotropy by releasing noradrenaline.
What controls the heart rate ?
The sinoatrial node is the pacemaker of the heart, it is innervated by the vagal efferent fibres to prevent the heart from having a too high frequency of beat.
What happen to the duration of the cardiac cycle when the heart rate increase.
The diastole phase shorten, the cardiac cycle last less than 1s.
Third heart sound
Pathological signs after 40 of fatigue of the ventricles that became too stiff. Heard during the filling phase.
What method do you use to auscultate the heart ?
All Patient Take Med
Aorta (right up), Pulmonary (left up), Tricuspid (right down), Mitral (left down)
Second heart sound
Closing of semilunar valve. First aortic valve then pulmonary valve.
How do the AV valves close ?
Pressure in the ventricles exceed pressure in the atrial, then the papillary muscle and their attached chordae tendinae contract preventing the AV valves leaflets from bulging back.
What does the Frank-starling law say ?
Preload volume increase ==> EDV increase ==> pressure increase
Preload volume decrease ==> EDV decrease ==> pressure decrease
Afterload volume increase ==> pressure increase ==> stroke volume decrease
Afterload volume decrease ==> pressure decrease ==> stroke volume increase
What does the preload affect ?
It influences the interaction between the myosin and actin forming the muscle contraction. The higher it is, the stronger the connection between the two will be.
Parasympathetic efferent fibres
Vagus nerve
Sympathetic efferent fibres
Cardiac nerve from the lower cervical and the upper thoracic ganglia.
Autonomic nervous system
Both the sympathetic and the parasympathetic. Consist of autonomic nerves conducting impulse from the central nervous system to the glands, smooth muscle and cardiac muscles.
Cardiac output
Total blood flow pumped per minute
Stroke volume
EDV minus ESV
Pressure gradient
Difference between the atrial and ventricular pressure.
Total energy of blood
Sum of the pressure energy and the kinetic energy (which is the square velocity of the blood flow).
What is a physiological shock ? What are the major causes ? What are the main symptoms ?
Life threatening clinical state characterised by deficiency of blood supply.
Caused by allergic reaction, significant blood loss, heart failure, blood infection,dehydration poisoning and burn.
Symptoms : low blood pressure, weak pulse, confusion, thirst, low glucose level, bone fracture, organ rupture,…