![Heart,computer illustration.The heart is a hollow sac (lower frame) of muscular tissue that pumps blood around the body.Small surface coronary blood vessels supply the heart muscle with blood.Four major blood vessels (upper Heart,computer illustration.The heart is a hollow sac (lower frame) of muscular tissue that pumps blood around the body.Small surface coronary blood vessels supply the heart muscle with blood.Four major blood vessels (upper](https://c8.alamy.com/comp/KY3X17/heartcomputer-illustrationthe-heart-is-a-hollow-sac-lower-frame-of-KY3X17.jpg)
Heart,computer illustration.The heart is a hollow sac (lower frame) of muscular tissue that pumps blood around the body.Small surface coronary blood vessels supply the heart muscle with blood.Four major blood vessels (upper
![Heart and great vessels (anterior view). The heart is enclosed in the pericardial sac, the inner… | Heart structure, Cardiovascular system, Human circulatory system Heart and great vessels (anterior view). The heart is enclosed in the pericardial sac, the inner… | Heart structure, Cardiovascular system, Human circulatory system](https://i.pinimg.com/736x/01/5d/ae/015dae55df927b1c7e304cccc17d5269.jpg)
Heart and great vessels (anterior view). The heart is enclosed in the pericardial sac, the inner… | Heart structure, Cardiovascular system, Human circulatory system
![19.6 Pericardium. The protective layers of the heart include the pericardial sac composed of an outer… | Anatomy models, Human anatomy and physiology, Heart anatomy 19.6 Pericardium. The protective layers of the heart include the pericardial sac composed of an outer… | Anatomy models, Human anatomy and physiology, Heart anatomy](https://i.pinimg.com/736x/df/c4/d6/dfc4d6823e4f10661fd2fbdd43633336.jpg)
19.6 Pericardium. The protective layers of the heart include the pericardial sac composed of an outer… | Anatomy models, Human anatomy and physiology, Heart anatomy
![Heart,computer illustration.The heart is a hollow sac (lower frame) of muscular tissue that pumps blood around the body.Small surface coronary blood vessels supply the heart muscle with blood.Four major blood vessels (upper Heart,computer illustration.The heart is a hollow sac (lower frame) of muscular tissue that pumps blood around the body.Small surface coronary blood vessels supply the heart muscle with blood.Four major blood vessels (upper](https://c8.alamy.com/comp/KY3X12/heartcomputer-illustrationthe-heart-is-a-hollow-sac-lower-frame-of-KY3X12.jpg)