Digestive System
Functions:
The function of the digestive system is to supply the body with
materials needed for the over 200 trillion cells in the body. It is composed of
organs for changing food chemically for absorption by body tissues. It also
serves to eliminate solid byproducts as wastes. The digestive system is
mainly one long, continuous tube that runs from the lips to the bottom of the
trunk. It takes up most of the space from the neck to the thighs.
Major parts and organs:
The major organs of the digestive system are the esophagus, the
stomach, the small intestine, the large intestine, and the liver. The
esophagus is a hollow tube, about ten inches long, that connects the neck to
the stomach. The esophagus is encircled by muscle tissue that contracts and
gets smaller, one by one, starting at the top. This forces the food to the
stomach, no matter what position you�re in, or if there is any gravity. The
stomach is a flexible bag surrounded by muscle, below the diaphragm.
When full, it may contain up to 1.5 liters(three pints) of food. Food may be
stored in the stomach from two to four hours. The small intestine is a tube
about 16 feet in length. The majority of digestion takes place here. The
large intestine is a large, wide, tube that measures five feet in length. It is
made up of four parts: the cecum, the colon, the rectum, and the anal canal.
The liver is the largest organ, weighing three to four pounds. It�s situated in
the upper right quadrant of the abdominal cavity, and is dark red in color. It
secretes bile, and is active in the formation of certain blood proteins and in
the metabolism of carbohydrates, fats, and proteins.
Interactions with other systems:
Two other systems that interact with the digestive system are the
Muscular and Skeletal systems. The muscles of the Muscular system are
in the walls of your digestive passages. These muscles move rhythmically to
push food along the digestive tract. The ribcage of the Skeletal system
protects most of the digestive system.
Diseases:
Some diseases of the digestive system are scurvy, pellagra,
hemorrhoids, and beriberi. Scurvy is a disease caused by a prolonged
deficiency of vitamin C, or ascorbic acid, in the diet. It is characterized by
progressive bodily weakness, spongy and inflamed gums, loose teeth,
swollen and tender joints, and a tendency toward ecchymosis. Vitamin C is
used for treating this. Pellagra is a dietary-deficiency disease resulting from
inadequate intake, or absorption of niacin, one of the components of the
vitamin B complex. Niacinamide is used to treat Pellagra. Hemorrhoids are
swelling, occurring in or around the rectum or at the anus, caused by
enlargements of the superficial veins. A hemorrhoid occasionally prolapses,
or protrudes from the anus, causing discomfort by strangulation; to relieve
the pain, the prolapsed hemorrhoid must be replaced within the anal sphincter
muscle. Surgery is one treatment for hemorrhoids. Beriberi is a
diet-deficiency disease caused by a lack of vitamin B1. Chronic deficiency is
known to cause two distinct forms of beriberi. When associated with low
calorie intake and inactivity, this disease tends to affect the nervous system.
The second form of beriberi, known as wet beriberi, is usually associated
with extremely high activity levels and a high carbohydrate intake.