digestion and absorption class 11th CBSE notes

 digestion and absorption class 11th CBSE notes though this chapter is included in CBSE for 2020 may be included in upcoming 2021 and 2022 syllabus.

• food is a very essential component of all of us. it is the basic requirements of living organisms.
• the process of digestion of food is called digestion. the process by which biomacromolecules into simpler substances by physical and chemical methods is called digestion.
• digestion of food is done by a specific system in our body called the digestive system.
• the digestive system consists of the alimentary canal and associated glands.
• the alimentary canal includes from the mouth to the anus.
• in the buccal cavity, the oral cavity has teeth and tongue and cavity.
• the three types are done in the buccal cavity: 1.thecodont:= the type of dentition in which each tooth is embedded in jaw socket bone, this is the type of attachment is called the thecodont.                                        2. heterodont:= the typ[e od dentition in which we have different types of teeth called incisors, canines, molars, premolars, etc.   3.diphyodont:= the type of dentition in which when milk teeth is converted into adult teeth strong teeth. 
• 32 teeth are permanent. the dental formula for the teeth is 2123.                                                                                                                                                       2123
• the hard chewing substance of the teeth made up of enamel called dentine, helps in the mastication of food.
• the tongue is a freely movable organ that contains papillae that have gustatory receptors in it which are responsible for the taste.
• the oral cavity, there is a common passage from the oral cavity called pharynx in which food and air pass from it serves as a common. it is differentiated by the esophagus and ovula serving as different passages.
• the cartilaginous flap serves as a prevention to food to enter in windpipe trachea. called epiglottis is a flap that is present in the laryngopharynx.
• the esophagus comes and is also called food pipe which helps swallow food inside and has peristalsis movements which occur in contraction and relaxations which helps to clog of food in the pipe when it is swallowed.
• the food comes into the stomach which is j shaped structure, has a sphincter to allow the food to pass from the esophagus to the stomach to digest.
• the sphincter which is called the gastroesophageal sphincter, allows food to pass from it.
• stomach divides into 4 parts: 1. fundus, 2. cardiac 3.body 4.pyloric .etc 
• the food then comes to small intestine from stomach through the pyloric sphincter, now the small intestine has parts called 1.ileum which is highly coiled in its way, 2. duodenum which C shaped in small intestine 3.jejunum which is long coiled which is present in the middle layer. 
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