CVS Harc 2 Flashcards
What are coronary arteries classified as?
Functional end arteries
They can anastamose but are insufficient if the main artery becomes occluded, leading to ischaemia.
What are the first branches of the ascending aorta?
RCA and LCA
They arise from the right and left aortic sinuses.
What is the function of vasa vasorum?
Supply blood to the walls of larger blood vessels
They are small blood vessels that provide nutrients to the outer layers of larger arteries and veins.
What is the consequence of ventricular contraction on coronary circulation?
Blood is pushed into the aorta, filling aortic leaflets
Back flow due to aortic elastic recoil closes the valve, filling coronary arterioles.
Which artery supplies the SA node in most people?
RCA supplies 60% of the SA node
The LCA supplies 40% of the SA node.
What is coronary dominance determined by?
Which coronary artery gives rise to the posterior descending artery
In left dominance, the entire interventricular blood supply is only supplied by one artery.
What are the three veins that drain into the coronary sinus?
Great cardiac vein, middle cardiac vein, small cardiac vein
These veins drain into the right atrium.
What condition is caused by atherosclerosis?
Coronary artery disease
It leads to insufficient perfusion, causing angina or myocardial infarction.
What are common occlusion sites in coronary artery disease?
- LAD
- RCA
- Left circumflex
These sites are frequently affected by blockages.
What is a coronary artery bypass graft used for?
To bypass blocked coronary arteries
It involves clamping behind the coronary sinus.
What is the cardiac skeleton?
Four rings that valves attach to, maintaining opening integrity
It separates the atria and ventricles.
What effect does sympathetic innervation have on the heart?
Increases heart rate and contractile force
It also increases cardiac output.
What happens when parasympathetic innervation is lost?
Causes tachycardic symptoms
It decreases heart rate and contractile force.
What is the primary pacemaker of the heart?
SA node
It typically generates 70 bpm.
What is AV block?
Disruption in the conduction system affecting the AV node
It may cover the fork from the SA node.
What causes heart block?
Ischaemia, infarction, fibrosis, and drugs
These factors can lead to disruption in conduction.
What is the function of the moderator band?
Passes from septum to anterior papillary muscle
Also known as septomarginal trabeculae, it plays a role in the conduction system.
What is the heart rate generated by the AV node?
40-60 bpm
It acts as a secondary pacemaker with a built-in delay.
What is the role of special cardiac muscle cells in the conduction system?
They depolarize faster than normal cardiac cells
This ensures proper initiation and coordination of the cardiac signal.
