Absorption, Biology

Absorption

The monosaccharides, amino acids and other products of digestion must be passed on to other tissues to be useful for the organism. The process by which the digested material from the alimentary canal enters the blood stream is known as absorption. In intracellular digestion the same cells are concerned with digestion and absorption but in higher multicellular animals there are usually separate tissues and areas of gut for enzyme production, digestion and absorption. In this section we will mainly be concerned with absorption of amino acids, sugars and fats released during extracellular digestion in vertebrates. In all vertebrates most of the absorption is localised in the intestine.

As you already know the wall of the vertebrate intestine is folded and ridged to increase the absorptive surface. These ridges or folds are covered by a velvet like pile of minute absorptive villi. These are highly specialised absorptive organs with a core containing a network of capillaries derived from blood vessels in the gut wall. Each villus also contains a central lymph capillary known as lacteal which begins blindly at the tip of the villus and drains into the main lymph channels of the gut wall. Lipids pass mainly into the lacteals while sugars and amino acids are absorbed directly by the blood capillaries. The villi and intestinal folds contain smooth muscles that contract to bring the villi in contact with the food in the intestine; and also maintaining the circulation in lacteals, lymphatics and small blood vessels.

1460_Absorption.png

Figure: Lining of mammalian small intestine a) Villus covered with digestive epithelium which consists of absorptive cell and occasional goblet cells. b)  An absorptive cell. The apical surface bears a brush border of microvilli.

Posted Date: 1/15/2013 5:39:19 AM | Location : United States







Related Discussions:- Absorption, Assignment Help, Ask Question on Absorption, Get Answer, Expert's Help, Absorption Discussions

Write discussion on Absorption
Your posts are moderated
Related Questions
OESTROU S CYCLE - Also known as heat period. Common in rabbit, cat, dog, sheeps. In this period desire for copulation occur. Possibility of fertilization is 100%.

The heart is the muscular pump that pushes blood through the circulatory system. Each heartbeat can be felt as an arterial pulse. The heart valves when closed prevent the blood fro

Define the role of Fluorine in Human Body? Fluorine is potentially a toxic element. Its essentiality for humans is not established although the role of fluoride in providing pr

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Explain about the Foods Effect on Drug Utilization? The following illustrations highlight the effect of food on drug utilization. Liver and green leafy vegetables can decrea

Q. Zonation in the lake biome? Precipitation that does not evaporate or penetrate the soil remains on the soil surface resulting in run off which flows down from the mountains

A healthy person is on a diet that having of very small amounts of water. A. This person will make a large volume of dilute urine with low amounts of dissolved solutes. B. T

Fensom and Spanner Electroosmotic Flow Hypothesis In electroosmosis the ions flow across a membrane in response to electrical gradient. Ions pull along water and other content

Disease Prevention for the High Risk Group   Interventions aimed at early diagnosis and appropriate management for reducing morbidity and mortality targeting people who suffer

Explain the Carbohydrate required for underweight - Nutritional Care? Liberal amounts of easy to digest carbohydrates should be included in the diet. The intake of dietary fibr