Essentials of Anatomy and Physiology

276 The Heart

Brachiocephalic (trunk) artery

Superior vena cava

Right pulmonary artery

Right atrium

Right coronary artery

Inferior vena cava

A

Left subclavian artery

Left internal jugular vein

Left common carotid artery

Aortic arch Left pulmonary artery

(to lungs)

Left atrium

Left pulmonary veins

(from lungs)

Circumflex artery

Left coronary artery

Left coronary vein

Left anterior descending

artery

Left ventricle

Right ventricle Aorta

Brachiocephalic artery

Superior vena cava

Left common carotid artery

Left subclavian artery

Aortic arch

Right pulmonary artery

Right pulmonary veins

Right pulmonary veins

Right atrium

Inferior vena cava

Tricuspid

valve

Pulmonary

semilunar valve

Left pulmonary artery

Left atrium

Left pulmonary veins

Mitral valve

Left ventricle

Aortic semilunar valve

Interventricular septum

Chordae Apex

tendineae Right ventricle Papillary

muscles

B

Figure 12–2. (A) Anterior view of the heart and major blood vessels. (B) Frontal section

of the heart in anterior view, showing internal structures.

QUESTION:In part B, in the right atrium, what do the blue arrows represent?