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Bundle of His: Comes after the AV node, not immediately after the SA node.

Purkinje fibers: Terminal conduction fibers in the ventricles; far downstream from the SA node.

AV bundle: Another name for the Bundle of His, which still comes after the AV node.

Intercalated discs: Structures that connect cardiac cells and permit coordination, but not the term for the group behavior.

Chordae tendineae: Tendinous cords of AV valves; unrelated to cell-unit behavior.

Systole: The contraction phase of the cardiac cycle, not a term for a cell collective.

Internal jugular vein in the neck: Venous pulsations are observed, not palpated as an arterial pulse.

Aorta in the chest: Not a routine palpable site.

Subclavian artery in the neck: Deep and not a common palpation site.

pressure of the blood: Not primarily—systemic blood pressure is mainly from cardiac output and vascular resistance; proteins contribute minimally.

filtration: They oppose filtration by favoring reabsorption (their oncotic pull counters hydrostatic push).

central venous: CVP reflects blood volume, venous tone, and right heart function, not plasma protein levels directly.

hydrostatic: Hydrostatic pressure is due to fluid column and pumping; proteins affect oncotic, not hydrostatic, pressure.

Tunica media: Middle layer made of smooth muscle and elastic fibers; not the innermost layer.

Tunica externa: Outermost connective-tissue layer (adventitia) that contains collagen and sometimes vasa vasorum; not the innermost.

Vasa vasorum: Small blood vessels that supply the walls of large vessels, located in the outer layers; not the innermost.

The semilunar valves are closing: Semilunar valves close at S₂ (second heart sound), not S₁.

The AV valves are opening: AV valves open during ventricular diastole (filling), not at S₁.

The semilunar valves are opening: Semilunar valves open during ventricular ejection (systole) but their opening is not what produces S₁.

An increase in parasympathetic stimulation: Parasympathetic activity lowers heart rate and typically reduces BP, so this would not increase BP.

A decrease in peripheral resistance: Lower peripheral resistance reduces BP (BP = CO × PR), so this would decrease BP.

A decrease in stroke volume: Lowers cardiac output and therefore tends to decrease BP.

It carries oxygen-poor blood to the tissues: That’s the systemic circuit's function (to deliver oxygen to tissues via arterial blood), so incorrect.

It carries oxygen-poor blood to the heart: Venous return from tissues brings oxygen-poor blood back to the heart, but the pulmonary circuit specifically moves blood from the heart to the lungs -so this is misleading/incorrect.

It carries oxygen-poor blood from the tissues: The systemic veins do that; the pulmonary circuit carries blood from the heart to the lungs, not directly from tissues.

Compression of a vein because of muscle contraction: That’s mechanical venous compression (skeletal muscle pump), not vasodilation.

Contraction of the ventricles which increases ventricular pressure: That describes ventricular systole, not vasodilation.

A decrease in the diameter of a blood vessel: That is vasoconstriction, the opposite of vasodilation.