Cardiovascular homeostasis I Flashcards
What is Pulmonary circulation
Blood is pumped from the heart to the lung, short distance and the pressure requirements are low
What is systemic circulation?
Blood pumped from the heart to the rest of the body, long distance with high aortic pressure
What is the main function of the heart?
To pump blood at a pressure high enough that it is able to circulate throughout the entire body and reach all the target organs
What does a P wave show?
Depolarisation of the atria
What does the QRS complex show?
Depolarisation of the ventricles
What does a T wave show?
Repolarisation of the ventricles
What sound does the closure of the AV valves make?
A ‘lubb’ sound, it is long and deep
Which valves vibrate as they close?
the AV valves (tricuspid and mitral)
What is the ‘second sound’?
Fast Closure of the pulmonary/ aortic valve as the ventricles relax- it is a higher pitched and shorter sound
Where is information sent to either increase or decrease rate of firing?
Information is sent to the SA node
What system controls the regulation of the heart rate?
The nervous system (specifically the autonomic)
What receptors on the heart stimulate the sympathetic system?
Beta-1-adrenoreceptors
What receptors on the heart stimulate the parasympathetic system?
M2 Muscarinic receptors (inhibit/s low down heart rate)
Why is the resting heart rate low in animals?
The parasympathetic system is dominating
What effect does the stretching of cardiovascular muscle have on the ventricles?
The force exerted due to the stretch further increases pressure inside the ventricle
this is called isovolumetric contraction