Healthy blood vessels are essential for proper circulation, as blood is pumped from the heart to carry nutrients to the cells throughout the body by way of the arteries and then returns to the heart through the venous system, according to Health911.com.

Blood infections, also known as sepsis, are very serious medical conditions that require prompt treatment. While the main cause of blood infections is an infectious organism in the blood, these organisms can enter the bloodstream in many ways. As a result, there are several causes of blood infections.

Lipitor (atorvastatin) is a cholesterol-lowering medication prescribed in dosages between 10 to 80 mg daily, depending on the patient. It lowers the amount of low-density lipoprotein (LDL) (“bad cholesterol”) to help combat heart disease by blocking an enzyme that the liver produces while making cholesterol.

Proteases are enzymes that catalyze the breakdown of proteins. Protein breakdown is a normal process necessary to maintain cellular homeostasis. Active proteases can be found throughout your body, including the digestive tract, inside cells and circulating in the blood.

Crab meat and other shellfish were once considered taboo if you were watching your cholesterol. Fortunately, that is no longer the case. Crabs, like all sources of meat, contain cholesterol. However, as long as you don’t overindulge, they can be a healthy option.

Deep heel bruises result from microscopic calcium fibers breaking apart. These fibers are normally interconnected to help form bones, so when a portion of the fibers is damaged, a deep heel bruise, or deep "bone bruise" occurs.

The nerve networks in the body are divided into two major nervous systems: the central nervous system and the peripheral nervous system. The central nervous system consists of the brain and spinal cord, and the peripheral nervous system consists of the nerve networks outside of the brain and spinal cord.

Reduced numbers of white blood cells, also known as leukopenia, means that you have fewer disease-fighting cells circulating throughout your body. Fewer than 3,500 white blood cells, or leukocytes, per microliter of blood is considered a low white blood cell count, although this number varies based on age and sex.

A comedic pratfall invariably elicits audience laughter, but a bruised tailbone is no laughing matter. Falling backward onto your bottom or a blow to the tailbone incurred during sports activities can leave you with a painful bruised tailbone, or coccyx.

Diabetes that begins during pregnancy is called gestational diabetes. This condition affects 5 to 9 percent of all pregnancies in the United States, and it is becoming more common, according to a July 2009 article in "American Family Physician." Pregnancy also aggravates preexisting type 1 and type 2 diabetes.

The spleen is a soft organ on the left side of the abdomen that helps to filter used red blood cells out of the body. Although humans can survive without a spleen, our ability to fight off certain infections may be impaired without it.

The main job of platelets is to make blood sticky so that it can form clots. This is important when you are injured so that you do not bleed to death. When you bleed, platelets swarm to the area and attempt to stop the blood flow.