Q:

What are the three main parts of the circulatory system?

A:

The three main parts of the circulatory system are the heart, the blood and the blood vessels. The purpose of the circulatory system is to transport oxygen throughout the body.

In humans, the heart is a fist-sized muscle located slightly to the left of center in the chest. It acts as an engine for the circulatory system, pumping blood through the blood vessels. It will beat approximately three billion times in an average human lifespan.

The blood vessels are hollow tubes that conduct blood from the heart to the body’s tissues and back again. There are three types: arteries, veins and capillaries. Arteries carry oxygenated blood away from the heart and to the tissues. The one exception to this is the pulmonary artery, which carries deoxygenated blood from the heart to the lungs. They are thick-walled, elastic vessels that contain no valves. Veins carry blood back to the heart after the body tissues have used the blood’s oxygen. They have thinner walls than arteries and contain valves to keep the blood from flowing backward. Capillaries are tiny vessels that connect arteries to veins. Because their walls are so thin, they allow oxygen and other nutrients to pass from the vessels to the surrounding tissue.

Blood is made of two parts: plasma and blood corpuscles (or cells). Plasma is the liquid portion of blood and is made mostly of water. There are three types of corpuscles: red blood cells, white blood cells and platelets. The red blood cells carry oxygen and carbon dioxide, white blood cells attack germs and foreign bodies and platelets help to clot the flow of blood in cuts or injuries.


Is this answer helpful?

Similar Questions

  • Q:

    How does a shark circulatory system work?

    A:

    In a shark's circulatory system, the heart pumps blood first to the gills where it is oxygenated, then to the organs and muscles, and finally back to the heart. To remain oxygenated, the blood must flow continually, and this is accomplished through the opening and closing of a shark's mouth as well as the muscle movements of its body.

    Full Answer >
    Filed Under:
  • Q:

    What are the organs in the circulatory system?

    A:

    The main organ in the circulatory system is the heart, according to Hillendale Health. The two other major parts of the circulatory system are the blood and the blood vessels.

    Full Answer >
    Filed Under:
  • Q:

    What serves as a heart in an earthworm's circulatory system?

    A:

    The aortic arches serve as a heart in an earthworm's circulatory system. There are five pairs of aortic arches, located near the head of the earthworm, that function much like a human heart.

    Full Answer >
    Filed Under:
  • Q:

    How do skeletal muscles aid the circulatory system?

    A:

    The skeletal muscles, the muscles that power voluntary movements of the body, aid the circulatory system as the primary method by which deoxygenated blood is pushed back to the heart through the veins. Veins have thin walls compared to arteries and are easily compressed as skeletal muscles contract, forcing blood along the vein. Backflow is prevented by the presence of valves within the veins, a feature arteries largely lack.

    Full Answer >
    Filed Under:

Explore