How the Heart Works
The heart is part of the circulatory system, along with the lungs and blood vessels. Just like in humans, a dog’s heart acts like a pump to drive the circulation of the blood around the body. With each heart beat, it delivers blood rich in oxygen and nutrients to all the vital organs and tissues, keeping the dog fit and healthy. The heart’s pumping power lies in its muscles. These are normally thick and powerful, helping blood reach as far as the outer extremities of the body.
Inside, the heart is made up of two halves; left and right. Each half of the heart is divided into separate chambers – the upper ones, known as the atrium, receive blood from the body where as the lower ones, the ventricles, pump it out again. In between these chambers are the heart valves, which open and shut in sequence to make sure the blood flows in the right direction. They are normally smooth and form a perfect seal when closed.
The lungs are the part of the body where vital oxygen is absorbed into the blood and waste carbon dioxide is removed from the blood. As your dog inhales, the air travels in through the airways and into small sacs called alveoli. There are tiny blood vessels surrounding the alveoli – this is where oxygen is absorbed and the carbon dioxide removed.
Blood vessels are the tubes which blood flows through to get around the body. Vessels carrying blood away from the heart are called arteries and those carrying blood back to the heart are called veins. Blood vessels have a layer of muscle in their walls that can contract and relax which helps to control blood pressure.
