A&P Cardiovascular Flashcards
Where is the heart located?
In the mediastinum, contained in a fibrous sac called the pericardium.
What are the three layers of the pericardium?
Visceral - adheres to the myocardium.
AKA epicardium
Parietal - adheres to the fibrous pericardium.
Fibrous - Contains the heart within a strong and inelastic sac.
What are the 3 layers of the heart wall?
Epicardium - AKA visceral pericardium
Myocardium - functional muscle of the heart
Endocardium - Highly specialized layer that prevents clots and turbulence.
Which ventricle is thicker due to the higher systemic circulation?
Left ventricle.
What is the percentage of cardio output that is sent through the atrium?
25% is sent through the atrial kick.
What does the SA node fire at?
60 - 100 BPM
What does the AV node and Bundle of His fire at?
40 - 60 BPM
What rate does purkinje fibers fire at?
20 - 40 BPM
What does the LCA supply?
Left ventricle
Anterior
Septum
Posterior
SA node 50%
What does the RCA supply?
Right ventricle
Inferior heart
Posterior heart
SA node 50%
AV node 80%
What happens in systole?
Contraction of ventricles
AV valves close
What happens in diastole?
Relaxation of ventricle
Contraction of atria.
What affects stroke volume?
Pre-load
Contractility
Afterload.
What is blood pressure?
Blood pushing against blood vessel wall.
What is hepatic circulation?
Blood that goes through the liver and spleen.
Filters approx 1l/min.
