The Human Heart

Location In the thoracic cavity, specifically the mediastinum. It's tipped slightly so that a part of it sticks out and taps against the left side of the chest. Notice how it is attached to the diaphragm in the picture.

Size of Heart The adult heart is approximately 14 cm long and 9 cm wide. Do these two people have the same size heart? No- Heart size varies with body size.

Covering of the Heart Pericardium- Covers the heart and proximal ends of the superior blood vessels

Wall of the Heart EPICARDIUM- outer layer, protects the heart by reducing friction MYOCARDIUM- middle layer, consists of cardiac muscle tissue that pumps blood out of the heart chambers ENDOCARDIUM- inner layer, houses specialized fibers that conduct cardiac impulses

Word Bank: ENDOCARDIUM, EPICARDIUM, MYOCARDIUM, PERICARDIAL CAVITY, PERICARDIUM

EPICARDIUMMYOCARIDUMENDOCARIUM 1 2 3

Heart Chambers and Valves

The Cardiac Cycle The Virtual Body What is the picture showing? -Why is some blood red and some blue? -Where does the blue blood go after it leaves the heart? -Where does the red blood go after it leaves the heart?

Heart Transplant Now watch this video of a heart transplant. Look for the structures you’ve just learned about.