The cephalic phase contains those stimuli that originate from the head. By seeing, smelling or anticipating food, the brain is able to inform the stomach to prepare for a meal. These stimuli from the head encourage the mouth to ‘produce an enzyme called salivary amylase’ which initiates the first stage of chemical digestion. The brain tells the stomach to produce gastric juice (which contains hydrochloric acid and pepsin) before food arrives, when the nerves contained in the tongue and cheek are motivated. 2.2 What happens in the cephalic stage?
Instead, the acids work to break down the food for easier digestion in the intestines. As the food is broken down to a thick paste-like substance known as chyme, it moves past the pyloric sphincter and into the small intestine. The first section of the small intestine, the duodenum, secretes digestive enzymes like amylase, maltase, sucrase, lactase, lipase and pepsin, to break down the chyme into even smaller parts that the body can then convert into usable energy. Some other organs that secrete chemicals to aid in the digestion process include the pancreas, liver, and gall bladder. The pancreas secretes trypsin and chymotripsin.
The liver, gallbladder and the pancreas begin to bestow to the digestive process once the chyme reaches the small intestine. A large part of the digestion and absorption of nutrients from food takes place once the chyme or food enters the small intestine. Secretion of bile from both the liver and the gallbladder acids with the digestion and absorption of fat. At the same time, digestive enzymes and bicarbonate secretions from the pancreas helps in the digestive process. The left-over materials not absorbed in the little intestine the moves into the large intestine by the sphincter.
The small intestine is the principal site of digestion and absorption. Enzymes from the pancreas, liver, gallbladder, and the small intestine itself combine to break down nutrients so that they can be absorbed. The pancreas supplies enzymes to digest proteins, fats and carbohydrates. The live produces bile required for emulsification of fat, and the gallbladder stores the bile until it is needed. The absorption of nutrients in the small intestine is facilitated by tiny projections called villi, which provide more surface area for absorption.
Digestion first begins in the mouth. The saliva in our mouths is what begins the process of digestion. As the food is chewed, a clear liquid called saliva is produced to help break down and moisten the food so that it is easy to swallow. The saliva is produced in a salivary gland located under the tongue. It coats the chewed food and transforms it into what is called a bolus.
After this the food is taken down a long tube, called the oesophagus, which takes the food from the mouth to the stomach. The movement of the food is helped by waves of contraction of the muscle surrounding the oesophagus, this is called peristalsis. Once the food enters the stomach a ring of muscle at the exit called the pyloric sphincter contracts and prevents the food from leaving. For the next two to three hours churning movements of the stomach produce further physical breakdown of food. The only chemical digestion that takes place in the stomach is the breakdown of proteins, which is from the meat in the
The mouth receives food and begins digestion by mechanically reducing the size of the solid particles and mixing them with saliva. Pharynx – The pharynx is in both the respiratory system and digestive system. The pharynx is a muscular tube, at the back of your throat when the nose and mouth join. This serves as a passageway for food and air. The tube being so muscular helps an individual with swallowing.
The stomach is not only our digestive system it absorbs food but, rather is a part of the digestive system and important for churning food into a consistency that is easier to digest for the rest of our intestines( Stomach and role in digestion). The Mucous cell, parietal cell, chief cell, and G cell all make up the four main cell types that spread all over the inner structure of the stomach (Stomach and role in digestion). The mucous cell produce mucus from preventing the epithelium from hydrochloric acid. Which is found in the fundic, cardiac, and pyloric region (Stomach and its role in digestion). (Ireland, 2012) Stated “Hydrochloric acid is one of the strongest acids used in laboratories and can be found in our stomach, as PH2.
Once the cobbler enters the mouth, teeth start chopping the food up while the tongue is incorporating it with the saliva from the salivary glands, this converts into a ball of food, called Bolus. The tongue advances the Bolus into the Pharynx, which is responsible for swallowing, through the esophagus. The bolus passes through a sphincter into the stomach. Upon entering the stomach it mixes with an acidy secretion known as Chyme. Some digestion takes place in the stomach few exceptions; the Chyme empties from the stomach into the small intestine within two thru six hours dependent upon the size of the meal (Grosvenor & Smolin, 2006).
This is a very essential part of hydrolysis as biomass consists of very large organic molecules and for this process to work efficiently we must break the large particles down into smaller particles. Think of it the same way our stomach works, before we digest the food that we eat, we must break it down. The large polymers, mainly consisting of proteins, fats and carbohydrates are broken down into amino acids, fatty acids and simple sugars. During this process hydrogen and acetate are also produced. These byproducts will be used in a later anaerobic digestion stage.