Final answer:
The heart is a vital organ located within the thoracic cavity. It has four chambers and four valves. The structure of the heart is closely related to its function as a pump.
Step-by-step explanation:
The heart is a vital organ located within the thoracic cavity, between the lungs in a space called the mediastinum. It is surrounded by a tough membrane known as the pericardium and sits in its own space called the pericardial cavity. The heart has four chambers - two atria and two ventricles - and four valves that help regulate blood flow.
The heart pumps blood throughout the body, supplying oxygen and nutrients to the cells and removing waste products. It is made up of three tissue layers: the epicardium, myocardium, and endocardium. The structure of the heart is closely related to its function as a pump, with the atria receiving blood and the ventricles pumping blood out to the rest of the body.