Gluten sensitivities typically affect your digestive system, skin or sinuses, but in certain circumstances, a gluten allergy can cause ear congestion and a temporary reduction in hearing.

The process by which dietary calories are absorbed is called metabolism. Metabolism starts with digestion. Digestion begins in the mouth where food is combined with saliva during chewing and carbohydrates begin to break down into simple sugars.

Voluntary muscles are one of three types of muscle in the body; smooth and cardiac are the other two types. There are more than 600 muscles in the body, and each falls into one of these categories.

Adults have 206 bones. Babies are born with about 300 bones, but many fuse together as the baby grows. According to St.

Nerve cells send signals along long wires called axons, which are insulated with a fatty substance called myelin. The myelin sheath allows signals to be transmitted rapidly from the nervous system to the rest of the body. When myelin is destroyed -- called demyelination -- nerve signals are slowed or stopped.

Ear piercing is one of the earliest types of body modification. It was replaced by the popularity of clip-on earrings in the 1900s, but pierced ears came back in style in the 1950s. Many people pierced their own ears at home until jewelry stores and doctors began offering the service.

Good posture is important for the protection of muscles, joints and ligaments. If you regularly sit or stand in positions that put unnecessary strain on your body, you may develop pain, injury, arthritis or abnormal positioning of the spine, according to the Cleveland Clinic.

At colleges and universities, anatomy and physiology are often combined into one course. This is because they are branches of the study of biology that are closely related.

An indigestible carbohydrate found in fruits, vegetables, whole grains and beans, fiber adds bulk to stools, speeds the movement of food through the digestive tract and promotes regularly. This can aid in the treatment and prevention of constipation.

No matter what your fitness goals are, you'll hear a lot about the "core." Personal trainers advise core-strengthening exercises, and articles in fitness magazines come out with a new "core" exercise routine every month.

The "master gland" of the body, your pituitary gland -- located at the base of your brain -- secretes hormones that control the function of other glands throughout your body. It controls a range of physiological processes, including pubertal development and reproductive health, muscle growth and cellular metabolism.

While the idea of burning pain radiating though your muscles might seem alarming, for many athletes it’s all too familiar. Lactic acid, a byproduct of hardworking muscles, is responsible for the painful sensation.