Oxygenated blood,
Mostly blood, and some plasma.
The ventricles are the lower heart chambers that contract to pump blood. The upper chambers, atria, also contract, but to a lesser degree.
systole
The heart is a muscle and gets its nurisment from blood that flows through it. And it also pumps and circulates blood through it in large vessels and chambers.
The heart is a muscle containing four chambers. These chambers are separated by one-way valves which will allow the blood only to move in one direction. An electric impulse stimulates the heart muscle to contract, forcing blood out into the circulatory system. As the muscle relaxes, more blood flows in, filling the chamber for the next contraction.
Myocardium is a type of muscle tissue. The reason why the myocardium receives its blood from coronary arteries and not from the cardiac chambers is because the blood from the cardiac chambers does not contain oxygen and nutrients.
Veins
Tunica Media
The heart is a pump that both circulates blood and uses it to obtain oxygen and nourishment. Circulating blood enters the Atria (top chambers), is pumped to the Ventricles (bottom chambers) and out. Every time the heart contracts or beats, this happens. Blood for nourishment enters the heart muscle via the coronary arteries, which are attached to the base of the Aorta (the vessel that leaves the Left Ventricle, and pumps blood to the body). When you have a heart attack, the heart is either quivering like a bowl of jello, or at a standstill. There is blood still in the chambers, but no pressure to push the blood into the coronary arteries. The heart muscle dies.
The pumps inside the heart are four chambers that work together to pump blood to your lungs and your body. There are two upper chambers called atria and two lower larger chambers called ventricles.
hemoglobin
It's aerobic