Other Organs in Digestion
What are the supporting digestive organs? Pancreas, Liver, Gallbladder is the organs, which are not directly involved in digestion but vital for digestion.
Organs support Digestion
There are organs that are not directly involving in the digestion process, but they indirectly provide a major contribution in the digestion of the foods. These organs are:
Pancreas – Digestive System
A grayish pink spongy ‘fish shaper’ organ of 15 cm long, that is located across the back of the abdomen, behind the stomach. The head side of the pancreas is on the right side connected to the duodenum (small intestine), and the tail extends to the left side of the body.
The pancreas is a dual function gland having both endocrine (have no ducts, secretes hormones in the blood stream, where it finds the target organ to influence its physiology) and exocrine glands (has ducted through which it releases products produced by it directly to the target organ to show its action).
Pancreas as an endocrine gland does secrets insulin, glucagon, and somatostatin.
- Glucagon helps to raise the blood glucose (or sugar) level (counter the action of insulin)
- Insulin stimulates body cells to utilize glucose (control carbohydrate metabolism)
- Somatostatin helps to regulate the glucagons and insulin secretion.
Pancreas as an exocrine gland does secrets pancreatic juice containing digestive enzymes that pass to the small intestine. Acinar cells of the pancreas secrete pancreatic enzymes through the pancreatic duct into the duodenum that assists digestion of food.
The pancreatic juice, that is a clear, alkaline (pH 7.8-8.4) liquid of 1-2 L/d containing digestive enzymes, which can help the intestine to break down the food for nutrient absorption.
Protective functions of the pancreas: The pancreatic juice contains bicarbonate (alkaline) that can neutralize acidic liquid coming from the stomach, so that it protects the intestinal mucosa to avoid erosion.
Digest foods for nutrient absorption: The pancreatic juice has digestive enzymes to break down the food and nutrients, such as protein, fat, starch, which are the three major nutrient materials.
Liver – Digestive System
The liver is a reddish-brown organ with four lobes of irregular size and shape. It normally weighs 1.3–1.6 kg (3–3.7 lb). The liver is a vital organ plays a major role in metabolism, including glycogen storage, decomposition of red blood cells, plasma protein synthesis, hormone production, and detoxification. It is the largest internal organ/gland in the human body. It is located just below the diaphragm in the right upper quadrant of the abdominal cavity.
It helps in the digestion of fats, convert glucose to glycogen, produce urea (in the urine), make certain amino acids (from proteins), detoxify the blood (remove harmful substance from the blood such as alcohol), storage of vitamins (A, D, K & B12) & minerals, and maintain a proper glucose level in the blood. It also produces almost 80% of the cholesterol needed for the body.
Cells in the liver produce the Bile; bile is a dark green to yellowish-brown fluid that helps fat digestion. The pile moves down through the bile ducts joins with the cystic duct to form the common bile duct. Bile is a composed of water, electrolytes, bile acids, cholesterol, phospholipids and bilirubin. Human adult can produce 400 to 800 ml of bile a day.
The liver is a vital and complex functioning organ. Important functions that are carrying out by the liver are:
- Produce proteins such as albumin
- Produce, store, and metabolize fats; include fatty acids that are use for energy and cholesterol.
- Metabolize carbohydrates and stores sugar (glucose) for future energy needs, which are utilizing by the red blood cells and the brain.
- Produce and secrete bile that helps digestion and absorption of fats and the fat-soluble vitamins A, D, E, and K.
- Eliminate body produced harmful biochemical products, such as bilirubin (breakdown product of old red blood cells) and ammonia (breakdown product of proteins)
- Detoxify by removing harmful drugs, alcohol, and environmental toxins.
Gallbladder – Digestive System
The gallbladder (also known as cholecyst, gall bladder, Biliary Vesicle) is small pear-shaped organ located just beneath the liver. In well develop adults it measures approximately 8 cm in length and 4 cm in diameter. The neck of the gallbladder tapers and extends as common bile duct, it stores and concentrates about 50 ml of bile and releases its contents into the duodenum when required for the digestion process.
The gall bladder concentrates bile by five fold during the fasting state by water and small electrolytes removal, but retains all other organic molecules.
In humans, the loss of the gallbladder usually tolerates easily.