Merck Manual

Please confirm that you are not located inside the Russian Federation

Loading

Overview of Blood

By

Ravindra Sarode

, MD, The University of Texas Southwestern Medical Center

Last full review/revision Jan 2018| Content last modified Jan 2018
Click here for the Professional Version
GET THE QUICK FACTS
NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version
Topic Resources

Blood is a complex mixture of

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
Click here for the Professional Version
Others also read

Also of Interest

Videos

View All
Acute Myeloid Leukemia
Video
Acute Myeloid Leukemia
Inside the hollow area of the bones is a spongy core called bone marrow. It is here, that...
Acute Lymphocytic Leukemia
Video
Acute Lymphocytic Leukemia
Inside the hollow area of the bones is a spongy core called bone marrow. It is here that stem...

SOCIAL MEDIA

TOP