Q:

What is the function of an arteriole?

A:

Arterioles facilitate and manage the flow of blood between the oxygen-rich arterial component of the circulatory system and the oxygen-poor venous loop. Dictionary.com describes arterioles as the smallest branches of an artery and notes that they terminate in capillary beds.

About.com Biology provides details about how arterioles function to encourage the circulation of oxygen-rich blood to the parts of the body that need it most. Each arteriole is equipped with a special valve, the precapillary sphincter, that opens and closes in response to the flexure and contraction of its tiny internal muscle. When open, these valves permit blood to flow out of the arterioles and into the capillary beds where gas and waste exchange can take place. When these valves are closed, arterial blood flows past the capillaries and directly into the venules through a structure called the thoroughfare channel. This has the effect of bypassing the surrounding tissue bed and shunting oxygen-rich blood to other areas of the body where it might be more urgently needed. An example of this process is the rerouting of blood to the digestive organs which arterioles undertake to improve the breakdown and absorption of nutrients from food. While blood is present in all parts of the body at all times, the capillary beds only contain blood when it is needed.


Is this answer helpful?

Similar Questions

  • Q:

    What is the function of precapillary sphincters?

    A:

    The purpose of the precipillary sphincter is to adjust the flow of blood into the capillaries. These smooth muscles contract and act as a valve to redirect blood to the area where the body needs it most. They encircle each capillary branch at its exit from the arteriole, according to Reference.com.

    Full Answer >
    Filed Under:
  • Q:

    How do you trace the flow of blood through the heart?

    A:

    The flow of blood through the heart can be traced by injecting a dye into the arteries through a procedure known as an angiogram. Another procedure, cardiac catheterization, involves using a catheter to inject the dye. Magnetic resonance angiography or MRA, uses MRI technology.

    Full Answer >
    Filed Under:
  • Q:

    How does blood circulate through the body?

    A:

    Blood circulation is regulated by the circulatory system, and blood is distributed throughout the body by the heart. It flows from the heart into arteries that branch into smaller veins and capillaries.

    Full Answer >
    Filed Under:
  • Q:

    What does the circulatory system do?

    A:

    The main function of the circulatory system is transporting blood, oxygen, hormones, nutrients and other important substances throughout the body. The circulatory system is actually two separate systems of circulation, pulmonary and systemic, both of which interact with the heart and cardiovascular system to pump blood throughout that system.

    Full Answer >
    Filed Under:

Explore