Dark-colored blood, called venous blood, is dark because it has become deoxygenated after having traveled through the body before returning to the heart drained of oxygen. Blood leaving the heart, called arterial blood, is pumped from the lungs back to the heart by the pulmonary artery, and it contains a large amount of oxygen for delivery around the body. Arterial blood, therefore, appears a brighter red than deoxygenated venous blood.Know More
Blood gets its color from red blood cells called hemoglobin, to which oxygen binds. Ninety-seven percent of the oxygen transported by the blood from the lungs is carried by hemoglobin. Besides carrying oxygen around the body, hemoglobin helps remove carbon dioxide from the body. The difference in color between venous blood and arterial blood is known as the arteriovenous oxygen difference. Venous blood is also colder than arterial blood due to its lower oxygen content and pH.
A popular and persistent misconception indicates that deoxygenated blood is blue because veins may appear to be blue due to the way light is diffused by the epidermis. Human skin may also take on a bluish color, known as cyanosis, sometimes as a result of certain medical conditions; however, deoxygenated human blood is never blue.Learn more about Blood
A vein is a blood vessel that carries blood toward the heart. There are four main types of veins: pulmonary and systemic, and superficial and deep.Full Answer >
A blood reservoir is an organ or vessel that holds large proportions of blood, and veins are vessels termed as the blood reservoirs of the body. This is because they hold the largest amount of blood, which is about 50 to 60 percent of the entire body’s blood volume.Full Answer >
Blood is responsible for transporting oxygen, carbon dioxide, nutrients, hormones and proteins in the body, according to KidsHealth. The blood also carries glucose, ions, amino acids and waste products, such as urea, through the body. Red blood cells carry hemoglobin, a chemical that gives blood its red color.Full Answer >
According to the University of Cincinnati's Clermont College, human beings have double circulation, which means that there are two separate loops through which blood travels. One loop, called the systemic loop, takes oxygenated blood to the body, while the other loop, called the pulmonary loop, carries blood to and from the lungs so that blood can absorb oxygen.Full Answer >