Overview of Blood

 Overview of Blood

By Ravindra Sarode, MD, The University of Texas Southwestern Medical Center

Last full review/revision Feb 2021| Content last modified Feb 2021

 

Click here for the Professional Version

 

Topic Resources

• 3D Models (0)
• Audios (0)
• Calculators (0)
• Images (0)
• Lab Test (0)
• Tables (0)
• Videos (1)  

 

Overview of the Blood

VIDEO

Blood is a complex mixture of

• Plasma (the liquid component)

• Red blood cells (the oxygen-carrying component)

• White blood cells (the cells that defend against infection)

• Platelets (particles that promote clotting)

The body contains about 5 to 6 quarts (about 5 liters) of blood. Once blood is pumped out of the heart, it takes 20 to 30 seconds to make a complete trip through the circulation and return to the heart.

Blood performs various essential functions as it circulates through the body. It delivers oxygen and essential nutrients (such as fats, sugars, minerals, and vitamins) to the body's tissues. It carries carbon dioxide to the lungs and other waste products to the kidneys for elimination from the body. It transports hormones (chemical messengers) to allow various parts of the body to communicate with each other. Also, it carries components that fight infection and stop bleeding.

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version