Question
Explain the process of absorption of the digested food.
✓
Answer
Absorption is a process by which the end product of digestion passes through the intestinal mucosa into the blood and lymph. The villi in the lumen of the ileum are the absorbing units, consisting of a lacteal duct in the middle surrounded by fine network of blood capillaries. The process of absorption involves active, passive, and facilitated transport.
Small amounts of glucose, amino acids, and electrolytes like chloride ions are generally absorbed by simple diffusion. The passage of these substances into the blood depends upon concentration gradients. However, some of the substances like fructose are absorbed with the help of the carrier ions like $Na ^{+}$.
This mechanism is called facilitated transport. Nutrients like amino acids, glucose, and electrolytes like $Na ^{+}$are absorbed into the blood against the concentration gradient by active transport. The insoluble substances like fatty acids, glycerol, and fatsoluble vitamins are first incorporated into small, spherical water-soluble droplets called micelles and are absorbed into the intestinal mucosa where they are re-synthesized into protein-coated fat globules called chylomicrons which are then transported into the lacteals within the intestinal villi and eventually empty into the lymphatic duct.
The lymphatic ducts ultimately release the absorbed substances into the bloodstream. While the fatty acids are absorbed by the lymph duct, other materials are absorbed either actively or passively by the capillaries of the villi (Figure). Water-soluble vitamins are absorbed by simple diffusion or active transport. Transport of water depends upon the osmotic gradient. The absorption of substances in the alimentary canal takes place in the mouth, stomach, small intestine, and large intestine.
However maximum absorption takes place in the small intestine. Absorption of simple sugars, alcohol, and medicines takes place in the stomach. Certain drugs are absorbed by blood capillaries in the lower side of the tongue and mucosa of the mouth. Large intestine is also involved in the absorption of more amounts of water, vitamins, some minerals, and certain drugs.
Small amounts of glucose, amino acids, and electrolytes like chloride ions are generally absorbed by simple diffusion. The passage of these substances into the blood depends upon concentration gradients. However, some of the substances like fructose are absorbed with the help of the carrier ions like $Na ^{+}$.
This mechanism is called facilitated transport. Nutrients like amino acids, glucose, and electrolytes like $Na ^{+}$are absorbed into the blood against the concentration gradient by active transport. The insoluble substances like fatty acids, glycerol, and fatsoluble vitamins are first incorporated into small, spherical water-soluble droplets called micelles and are absorbed into the intestinal mucosa where they are re-synthesized into protein-coated fat globules called chylomicrons which are then transported into the lacteals within the intestinal villi and eventually empty into the lymphatic duct.
The lymphatic ducts ultimately release the absorbed substances into the bloodstream. While the fatty acids are absorbed by the lymph duct, other materials are absorbed either actively or passively by the capillaries of the villi (Figure). Water-soluble vitamins are absorbed by simple diffusion or active transport. Transport of water depends upon the osmotic gradient. The absorption of substances in the alimentary canal takes place in the mouth, stomach, small intestine, and large intestine.
However maximum absorption takes place in the small intestine. Absorption of simple sugars, alcohol, and medicines takes place in the stomach. Certain drugs are absorbed by blood capillaries in the lower side of the tongue and mucosa of the mouth. Large intestine is also involved in the absorption of more amounts of water, vitamins, some minerals, and certain drugs.
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Endocrine glands control and co-ordinate the body functions through secreting certain chemical messengers called hormones. Due to certain physiological reasons; the blood glucose level of an otherwise normal person
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a) Give the possible cause for the increase in blood glucose level.
b) What is the chemical nature of this hormone? Discuss its role in the body.
c) How can this condition be reversed.