The heart's layers, chambers, valves, and conduction pathway, plus how arteries, veins, and capillaries move blood, mapped to what the HESI A2 anatomy and physiology subtest asks.
ObjectiveA.4.1Read7 minExam weightCirculation, Respiration and Maintenance ≈ 28% of Anatomy & Physiology
This lesson is part of the full Study Guide
Unlock every lesson, unit, and quiz across every subject. The Anatomy & Physiology circulation, respiration and maintenance unit is included.
Trace one drop of blood through the four heart chambers, valves, and both circuits.
Name the three layers of the heart wall and the three layers of a vessel wall.
Explain what an ECG actually measures and why the P, QRS, and T waves appear in that order.
What the lesson concludes
The right side of the heart is the pulmonary pump, the left side is the systemic pump, and the left ventricle's wall is thickest because it does the most work.
Blood is roughly 55 percent plasma and 45 percent formed elements: red cells, white cells, and platelets.
The heartbeat starts at the sinoatrial node, so the ECG's P wave, QRS complex, and T wave record electrical timing, not the mechanical squeeze itself.
Arteries carry blood away from the heart under high pressure, veins return it under low pressure, and capillaries are where the actual exchange happens.