Heart Anatomy - Quick Notes

Heart anatomy

• The heart is a muscular, chambered organ of the circulatory system; blood is the circulating fluid.
• Size: roughly the size of a clenched fist.
• Location: in the thoracic cavity between the lungs; protected within the pericardium (the pericardial sac).

Chambers and septa

• The heart has $2$ atria and $2$ ventricles.
• Atria (upper chambers) are separated from each other by the interatrial septum.
• Ventricles (lower chambers) are separated from each other by the interventricular septum.

Valves

• The atrioventricular valves separate the atria from the ventricles:
  • Right side: tricuspid valve with $3$ cusps.
  • Left side: mitral valve with $2$ cusps.
• These valves guard the openings to the ventricles (preventing backflow during contraction).

Additional context

• The heart sits within the pericardial cavity and is the central pumping organ that drives blood through the vessels of the circulatory system.