Layers and Coronary Circulation
What is the middle (thickest) layer of the heart?
Myocardium
What is the fibrous skeleton of the heart and what is its function?
The valves; it slows down conduction to slow heart rate.
During prepotential of the heart, rapid influx of which ion contributes to depolarization?
calcium
What is the opening in the fetal heart that connects the atria?
Foramen ovale
Which side of the heart is the pulmonary pump?
Right
Where does the heart sit in the thorax?
Mediastinum
Which structures in the conduction system depolarize the outer ventricle walls?
Purkinje fibers
What happens if there isn't enough calcium in the contractile cells?
Contraction force decreases
What is the remnant of the ductus arteriosus called in the adult heart and what was its purpose in the fetal heart?
The ligamentum arteriosum; to connect the aorta with the pulmonary trunk.
Which ventricle has a thicker myocardium and why?
Left; systemic blood flow so has to pump harder
The viscreal layer of the pericardium is also known as:
The epicardium
The right side of the heart contains oxygen-rich or oxygen poor blood?
Oxygen-poor blood
What happens if there's not enough calcium in the nodal cells?
Heart rate slows
How can you calculate cardiac output?
Multiply stroke volume and heart rate
Where does coronary circulation route arise from?
The aorta
What is found between the visceral and parietal pericardium?
Pericardial cavity filled with pericardial fluid to reduce friction between organs.
Blood flows back into the left atrium from the lungs via the:
Pulmonary veins
What does the T wave of an ECG show?
Ventricular repolarization
Which three things increase stroke volume and therefore cardiac output?
Increase preload, increase calcium via noradrenaline, decrease afterload
Which muscles prevent eversion of the AV valves?
Papillary muscles
Where does all venous blood from coronary circulation drain into the right atrium from?
Coronary sinus
From the left ventricle, blood is then pumped through the ____ to the ________
Aortic valve; aorta
What makes the "dubb" sound of the heart?
The semilunar valves closing
Which nerve decreases heart rate and therefore decreases cardiac output?
Vagus nerve
What is the anatomical right-most artery that branches off of the arch of the aorta?
Brachiocephalic trunk