The maxim 'Knowledge is power and cure of all evils' inspires me to write down this article for people to know their digestive system which is primarily responsible of all their health issues. I hope knowledge of this primary source of health would go a long way in making a reader healthy is utilized properly. The digestive tract begins with stomach and ends at rectum with its attached subsidiaries such as pancreas, liver, etc.
Stomach of a person works as basic reservoir of food and a mixer of its various components. Proteins and Carcinogens (cancer-producing substances) get digested here. Apart from this, it works as an antiseptic acid barrier between the food intake and its later digestion process. Water, salt, monosaccharide, alcohol and certain drugs get absorbed here from the food for further uses. Its capacity grows to about 2 litres in adults, and it is located on left hand side of the abdomen, half behind the ribs and half below them.
Mixed up food from the stomach goes to small intestine in small doses which is about 6 meter long, consisting of 3 sections - Duodenum, Jejunum and Ileum. Digestion of food is completed here with absorption of the digested contents of the food. The digestion of food is facilitated by addition of bile from Liver via gall bladder, and other substances from Pancreas.
Large intestine coming next to the small intestine has 8 sections one after the other in the following order with their approximate lengths as provided below for an adult person.
Appendix - 2 to 20 cm in length with an average of about 9 cm with a diameter of 5 mm in adults. Its size is larger in children.
- Caecum - 6 x 7.5 cm
- Ascending colon - 12.5 cm
- Transverse colon - 50 cm
- Descending colon - 25 cm
- Sigmoid colon - 38 cm
- Rectum - 12.5 cm
- Anus canal - 2.8 cm
Overall function of the large intestine is to store faecal matter until its excretion and to absorb fluids and solutes from it.
Liver is a wedge shaped gland and weighs 1400 to 1800 gm in male and 1200 to 1400 gm in female adults. Thus, it is the largest gland in human body located opposite to stomach mainly on the right side but extending partially to the left side too of the abdomen. Its main function is to create and secret bile. Additionally, its functions include -
- Metabolic functions - Carbohydrates, fats, proteins
- Synthetic functions - Bile, Prothrombin
- Excretory functions - Drugs, Toxins, Poisons, Cholesterol, Bile pigments, Heavy metals
- Protective functions - Antibody formation
- Storage functions - Glycogens, Fat, Iron, Vitamins A and D, Blood
Gall bladder stores bile received from liver and sends it to small intestine keeping a balance of it. Additionally, it absorbs water and salts and dissolves cholesterol after its absorption.
Pancreas is a J-shaped organ weighing about 90 gm. It secrets digestive juice and hormones like insulin, and provides them to small intestine at the point where Gall bladder provides bile. Its secretions are listed below -
- Polypeptides (protein) and Toypcin used in synthesis of lower Peptides (Di-amino acids),
- Starch, Glycogen and Amylase used in synthesis of Disaccharides,
- Fat and Lipase used in synthesis of Fatty acids and Glycerol,
- Insulin for utilization of sugar in cells as source of energy
It is a lymphatic organ which filters blood and plays an important role in immune response of body. It is located on the left side and just below ribs and stomach. Its main function is to remove debris of damaged cells, red blood corpuscles, and other microorganism. Its immune response role is performed through circulation of antigens.
Main function of kidneys is to remove waste products of metabolism and excess water and salt from blood for which blood passes through them. In an adult, each kidney weighs about 150 gm and these are normally in a pair.
Umbilicus forms the junction of Vitello-intestine duct of small intestine, excretory (urachus), and Vascular umbilical vessel (aponeuratic fiber). It forms the boundary for fluid flow in the body in lower and upper parts of body. Water and blood don't flow across this line in the body. It is also the meeting point of four folds of the embryonic plates in the body. It is being supplied by a segment of spinal cord and plays an active role in overall health of the person.