Cardiovascular System Quiz

The heart is situated in the mediastinum, between the lungs, slightly left of center.

Atrial systole; ventricles are in diastole (relaxation). Blood moves from atria into ventricles, with a rapid initial filling phase followed by a slow filling phase.

Phase of the cardiac cycle where all four valves are closed, building pressure in the ventricles.

The ventricles contract, pushing blood out to the lungs and body. Aortic and pulmonic valves are open.

Passive ventricular filling; the ventricles relax, filling back up with blood. The AV valves are open.

The aortic valve is best heard in the second intercostal space, on the right sternal border.

Located at the apex (PMI); best heard at the fifth intercostal space, mid-clavicular line.

Normal right atrial pressure is 4 mmHg, fluctuating between 0 and 8 mmHg.

A tough, protective outer layer of the heart that prevents overstretching and anchors the heart to surrounding structures..

A thin, double-layered membrane enclosing the heart that reduces friction during heartbeats by secreting fluid. This lubrication helps the heart move smoothly.

The outer heart layer; the visceral layer of the serous pericardium.

The muscular layer of the heart, particularly in the atria, that facilitates pumping of blood.

The muscular layer of the heart, particularly in the ventricles, that contracts to propel blood.

The left ventricle's (LV) myocardium is significantly thicker than the right ventricle's (RV). This difference is due to the higher pressure needed to circulate blood throughout the body.

The inner lining of the heart chambers, including the heart valves. It's smooth and continuous with the blood vessels.

The left ventricle's (LV) myocardium is structured to sustain high pressures, maintaining stroke volume during changes in blood pressure.

Optimal pressure in the aorta during diastole, crucial for coronary perfusion.

Heart valves between atria and ventricles, preventing backflow.

Heart valves between ventricles and arteries, preventing backflow.

Valve area between right atrium and right ventricle, typically 7-10 cm².

Valve area between left atrium and left ventricle, typically 2-6 cm².

Decreases heart rate (chronotropy), conduction speed (dromotropy) and contraction force (inotropy), causing coronary vasodilation.

Regulates blood pressure by sensing changes in blood pressure via carotid and aortic baroreceptors to the Cardio Inhibitory Center.

Reflex increasing heart rate by responding to increased stretch in the right atrium, opposite to carotid/aortic reflex.

Myosin length remains constant during muscle contraction; actin filaments shorten.

Myosin head and arm structures that facilitate muscle contraction by interacting with actin.

Regulatory proteins on actin filaments that block myosin binding sites in a relaxed muscle.

Calcium ions released by nerve stimulation bind to troponin, causing tropomyosin to move and expose myosin-binding sites on actin.

ATP hydrolysis powers the myosin head's movement, which pulls on actin, causing muscle contraction. ATP binding causes myosin to detach from actin.

Invaginations of the sarcolemma that allow action potentials to spread deep into muscle fibers, allowing for calcium release.

Volume inside the ventricle at the end of diastole; determined by venous return and blood left in the LV at the end of systole.

Resistance to ejection during systole, primarily determined by aortic systolic pressure.

A birth defect with four problems in the heart: a hole between the lower heart chambers (VSD), aorta positioned over the hole, a narrow pulmonary artery, and a thickened right ventricle.

A condition where the structures on the left side of the heart don't develop properly, leading to reduced blood flow to the body.

Problems in the heart where oxygen-rich and oxygen-poor blood get mixed together.

A birth defect where the large blood vessels leading from the heart are switched.

The right ventricle of the heart thickens due to extra work.

The closing of the ductus venosus, foramen ovale, and ductus arteriosus after birth, changing the circulatory system to adult pattern.

Heart position and size change, along with lower pulmonary vascular resistance (PVR) and higher systemic vascular resistance (SVR), leading to a stronger left ventricle and heart rate between 100-180 bpm.

Heart defects present at birth, categorized by their effects on pulmonary blood flow (increased or decreased) or outflow tracts (obstructed).

A serious complication of congenital heart defects, where pulmonary vascular resistance equals or exceeds systemic resistance, reversing the shunt.

A heart defect where blood is shunted from the higher-pressure left side of the heart to the lower-pressure right side, leading to the high pressure on the pulmonary side.

A heart defect leading to less blood flow to the lungs, often causing a right-to-left shunt and cyanosis, a bluish tint from lack of oxygen.

A heart defect blocking blood flow out of the heart. No shunt is involved.

A heart defect where desaturated and saturated blood mix within the heart chambers or major arteries.