NUTRITION IN HUMANS
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Nutrition in humans is a complex process.
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The food passes through a number of organs in the body that together forms the alimentary canal or the digestive system.
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The digestive system is a group of organs responsible for the conversion of food into nutrients and energy needed by the body.
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With the help of secretions of various glands like salivary glands, liver, gall bladder, pancreas, etc., the food is broken down into simpler substances.
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The process of nutrition in humans involves five stages:
Ingestion:
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Ingestion is the process of consuming something and taking it into the body.
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In human beings, ingestion most commonly occurs through the mouth.
Teeth:
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Teeth help us chew our food, making it easier to digest.
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An adult human being has 32 teeth, 16 in each jaw.
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Each tooth is covered with a hard substance called enamel.
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Our teeth are embedded in gums.
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Healthy gums are must for healthy teeth.
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Teeth need to be kept clean to prevent their decay.
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Our mouth has four different kinds of teeth.
Types of Teeth:
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Our teeth look different from one another because they are designed to do different things.
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Humans have two sets of teeth, primary (or baby) teeth and then permanent teeth, which develop in stages.
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There are four different types of teeth. They are:
Incisors:
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They are the teeth in the very front side of the mouth.
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They're the sharpest teeth, built to cut food and shaped to shovel the food inward.
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They are also called biting teeth.
Canines:
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These teeth are in the corners of our mouth.
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They're meant for grasping and tearing food.
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They have very long roots.
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They are also called tearing teeth. They have very sharp edges.
Premolars:
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Premolars are located just behind our canine teeth.
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Premolars have a more flat chewing surface because they're meant for crushing food.
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They have broader grinding surfaces and therefore help in chewing and grinding of food.
Molars:
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Molars are the last teeth towards the back of our mouth.
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Molars are much bigger than the premolars and have bigger, flatter chewing surfaces because their function is to chew and grind the food into smaller pieces.
Table: Types of Teeth with Their Number and Function
