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.

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.

Sodium is one of the major electrolytes, carefully maintained within a narrow normal range and necessary for proper functioning of your body’s systems. Low sodium levels, or hyponatremia, occur in a wide variety of medical disorders including cancer.

Red blood cells are vital to your health and well-being, carrying oxygen to cells throughout your body and carbon dioxide away from them so that it can be expelled. A number of nutrients are involved in the production, maintenance and function of red blood cells.

The small veins in the legs can be damaged by disease, advanced age or trauma. The location of the injured veins is important in determining the cause. Identifying what produced the injury is the first step in prevention and treatment; failing to do so can potentially lead to serious and longterm complications.

Gastrointestinal, or GI, bleeding means bleeding that begins in the gastrointestinal tract. MedlinePlus states that the amount of gastrointestinal bleeding can be undetectable, however, in some cases it can be extensive and dangerous to the life of the individual.

Vitamins play a significant role in many of the functions inside your body. Your cardiovascular health depends on your vitamin intake as well. Certain vitamins keep your blood vessels healthy by maintaining their pliability and reducing hardness.

Honey is often perceived as a healthier sweetener alternative because it is more natural -- like agave syrup, black strap molasses and maple syrup. However, whether you eat refined table sugar or honey, your body reacts the same way. Sugar is sugar.

Muscles hold enough energy stores for a short burst of activity. After that, they depend on increased blood supply to deliver oxygen, blood sugar and other nutrients to manufacture more energy.