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Sep 21, 2023 · Functions of the Digestive System. Ingestion: The intake of food through the mouth. Digestion: Breaking down complex food substances into simpler molecules through both mechanical and chemical means. Absorption: The uptake of digested nutrients into the bloodstream via the small intestine.
Feb 24, 2023 · There, most nutrients are absorbed from the lumen of the alimentary canal into the bloodstream through the epithelial cells that make up the mucosa. Lipids are absorbed into lacteals and are transported via the lymphatic vessels to the bloodstream (the subclavian veins near the heart).
Study with Quizlet and memorize flashcards containing terms like Functions: to take in food, break it down into tiny nutrient molecules, _____these molecules into the bloodstream and _____ the body of indigestible remains., Gastrointestinal (GI) Tract: 30-foot long, muscular tube winding through the body: mouth,pharynx, _____, stomach, small intestine, _____, anus.It _____ food (breaks it down ...
Jan 17, 2023 · The food that remains undigested and unabsorbed passes into the large intestine. Absorption of the majority of nutrients takes place in the jejunum, with the following notable exceptions: Iron is absorbed in the duodenum. Vitamin B12 and bile salts are absorbed in the terminal ileum.
The digestive system includes the organs that _________________ the food, transport the ingested material, digest the material into smaller usable components, __________________ the necessary digested nutrients into the bloodstream, and expel the waste products from the body. ingest; absorb.
- Chemical Digestion
- Carbohydrate Digestion
- Protein Digestion
- Lipid Digestion
- Nucleic Acid Digestion
- Absorption
- Carbohydrate Absorption
- Protein Absorption
- Lipid Absorption
- Nucleic Acid Absorption
Large food molecules (for example, proteins, lipids, nucleic acids, and starches) must be broken down into subunits that are small enough to be absorbed by the lining of the gastrointestinal tract. This is accomplished by enzymes through hydrolysis. The many enzymes involved in chemical digestion are summarised in Table 12.7.1. Table 12.7.1.The dig...
The average American diet is about 50 percent carbohydrates, which may be classified according to the number of monomers they contain of simple sugars (monosaccharides and disaccharides) and/or complex sugars (polysaccharides). Glucose, galactose, and fructose are the three monosaccharides that are commonly consumed and are readily absorbed. Your d...
Proteins are polymers composed of amino acids linked by peptide bonds to form long chains. Digestion reduces them to their constituent amino acids. You usually consume about 15 to 20 percent of your total calorie intake as protein. The digestion of protein starts in the stomach, where HCl and pepsin break proteins into smaller polypeptides, which t...
A healthy diet limits lipid intake to 35 percent of total calorie intake. The most common dietary lipids are triglycerides, which are made up of a glycerol molecule bound to three fatty acid chains. Small amounts of dietary cholesterol and phospholipids are also consumed. The three lipases responsible for lipid digestion are lingual lipase, gastric...
The nucleic acids DNA and RNA are found in most of the foods you eat. Two types of pancreatic nuclease are responsible for their digestion: deoxyribonuclease, which digests DNA, and ribonuclease, which digests RNA. The nucleotides produced by this digestion are further broken down by two intestinal brush border enzymes (nucleosidase andphosphatase)...
The mechanical and digestive processes have one goal: to convert food into molecules small enough to be absorbed by the epithelial cells of the intestinal villi. The absorptive capacity of the gastrointestinal tract is almost endless. Each day, the gastrointestinal tract processes up to 10 litres of food, liquids, and GI secretions, yet less than o...
All carbohydrates are absorbed in the form of monosaccharides. The small intestine is highly efficient at this, absorbing monosaccharides at an estimated rate of 120 grams per hour. All normally digested dietary carbohydrates are absorbed; indigestible fibres are eliminated in the faeces. The monosaccharides glucose and galactose are transported in...
Active transport mechanisms, primarily in the duodenum and jejunum, absorb most proteins as their breakdown products, amino acids. Almost all (95 to 98 percent) protein is digested and absorbed in the small intestine. The type of carrier that transports an amino acid varies. Most carriers are linked to the active transport of sodium. Short chains o...
About 95 percent of lipids are absorbed in the small intestine. Bile salts not only speed up lipid digestion, they are also essential for the absorption of the end products of lipid digestion. Short-chain fatty acids are water soluble and can enter the absorptive cells (enterocytes) directly. Despite being hydrophobic, the small size of short-chain...
The products of nucleic acid digestion—pentose sugars, nitrogenous bases, and phosphate ions—are transported by carriers across the villus epithelium via active transport. These products then enter the bloodstream.
- Anna Chruścik, Kate Kauter, Louisa Windus, Eliza Whiteside
- 2021
These products then enter the bloodstream. Mineral Absorption. The electrolytes absorbed by the small intestine are from both GI secretions and ingested foods. Since electrolytes dissociate into ions in water, most are absorbed via active transport throughout the entire small intestine.
