Heart Structure & Function
The heart acts as two pumps in one organ. The right side serves which specific circulation?
pulmonary circuit
The tricuspid valve is found between which two chambers?
Right atrium and right ventricle
The term systole refers specifically to what phase of the heartbeat?
ventricular contraction
the coronary arteries originate from which vessel?
the aorta
a temporary chest pain caused by reduced oxygen to the heart muscle is known as what?
Angina pectoris
What chamber has the thickest wall and why?
Left ventricle because it must generate enough pressure to pump blood through the systemic circuit.
During relaxation, which valves prevent backflow from the arteries into the ventricles?
semilunar valves AKA aortic semilunar valves and pulmonary semilunar valves
The impulse from the SA node is delayed at the AV node for what crucial reason?
to allow the atria to complete contraction before the ventricles contract
the left coronary artery divides into which two major branches?
Anterior Interventricular artery and Circumflex artery
A myocardial infarction occurs when what happens?
a coronary artery becomes blocked, leading to death of cardiac tissue
The coronary sulcus marks the boundary between which two heart structures?
the atria and the ventricles
Which valves are supported by chordae tendineae and papillary muscles?
atrioventricular valves
What structure transmits impulses from the AV node to the ventricles?
atrioventricular bundle AKA Bundle of His
the coronary sinus drains blood from the myocardium into which heart chamber?
right atrium
In an MI, why do heart cells die quickly when deprived of oxygen?
because cardiac muscle relies almost exclusively on aerobic metabolism (aerobic requires oxygen)
The fossa ovalis in the right atrium is a remnant of what fetal structure?
the foramen ovale
What mechanical event immediately follows ventricular systole?
closure of semilunar valves
How do gap junctions within intercalated discs contribute to the synchronization of the heartbeat?
They allow ions to pass directly between cells, enabling rapid spread of action potentials.
Which vein runs alongside the anterior interventricular artery?
great cardiac vein
explain how coronary artery disease can progress to heart failure
Hence the term "heart failure"
Explain why the left and right ventricles contract simultaneously even though they pump to different circuits.
They pump simultaneously because the cardiac conduction system synchronizes impulses to both ventricles through Purkinje fibers.
During which phase of the cardiac cycle are the AV valves open and the semilunar valves closed?
ventricular filling AKA diastole
What structure is known as the pacemaker of the heart? What structure is known as the gatekeeper of the heart?
pacemaker = SA node
gatekeeper = AV node
Why is coronary circulation considered the heart's "functional blood supply"?
because it delivers oxygen-rich blood to the myocardium itself, not to other organs
A patient develops severe fatigue, fluid buildup in tissues, and shortness of breath due to a weakened myocardium. Identify this disorder and explain the reason it's happening.
Congestive heart failure. The heart cannot pump enough blood to meet oxygen demands of the body. This means not enough oxygen is reaching the body's tissues and muscles, making the patient feel tired (fatigue). Because the heart isn't pumping effectively, there is increased pressure within vessels causing fluid retention (fluid build-up).
This patient is short of breath, telling us the fluid retention is likely in the lungs. What kind of congestive heart failure does this patient have?