The mouth and the salivary glands are the beginning of the digestive tract and digestion begins before the first bite of food is taken. The salivary glands can be triggered by the smell of food, which then secrete saliva, causing the mouth to water. The saliva increases once food has actually been tasted and the structure of the salivary glands begins to relate to its function. The mouth begins to chew and break down food into small pieces that can eventually be digested. More saliva is produced in order to begin the procedure of breaking down food so that the body can absorb it.
Task 1: A brief introduction to digestion (i.e. Why we need to digest food, in one paragraph). Also explain the main processes involved, use one short paragraph for each. (Criteria 1): Digestion is the breaking down of food and drink into a smaller part so the body can use them to build and nourish cells and to provide energy as the body cannot absorb food without being broken down into smaller pieces. When we eat our food it is broken down into nutrients then absorbed into the bloodstream, our body then discards the indigestible parts of the food, this process is called digestion.
The first function of the digestive system is the intake of food; the mouth is responsible for this as this is where food enters the body. Enzymes inside the mouth serve two purposes, one is to kill bacteria and two, begin digestion. Salivary Amylase begins to breakdown starch, carbohydrate in our food. Lingual lipase is an enzyme that stays neutral in the mouth but is active when it reaches the stomach. You should note that enzymes are like tiny biochemical machines that disassemble large macromolecules like proteins, lipids carbohydrates into smaller molecules, the breakdown of these foods continue throughout the digestive system until they are ready to enter the blood stream by absorption.
The intestinal walls consist is three layers. The inside layer is the mucosa and it is responsible for the digestion and absorption of food. The middle layer is known as muscle that helps push the food threw the intestines. Last is the outer layer of the intestines that is known as the serosa. The serosa is a smooth so that
It begins in the mouth, where food is taken into the body and chewed to break it into smaller pieces, then amylase – a digestive enzyme produced in the body – is added to it through human saliva. Amylase is a carbohydralase and breaks down the carbohydrates within a food. This allows the body to take some of the nutrients from the food straight away. Once the food is swallowed it enters the pharynx before it is transported to the oesophagus, the pharynx converts the food into bolus. Bolus is chewed food which had been broken down with various enzymes produced in the mouth, it is much easier to digest than food which has just been chewed.
While he is chewing his food, the salivary glands will begin to produce saliva and amylase, produced by enzymes. This will in turn break down some of the carbohydrates. Also the chewing motion will break down the food and the tongue will form it into a small bolus for easy swallowing. The
the anus ). Digestion begins with the mouth. The teeth are used to break down the food into smaller molecules to be passed down the oesophagus and into the stomach. The stomach is where most of the digestion takes place, this leads to the small intestine; a narrow tube for which most of the absorption of nutrients takes place. The small intestine leads to the large intestine, another tube for which absorption takes place.
Blood glucose levels drop again after eating and the Lateral hypothalamus is activated (which initiates feeding) and we become hungry and the process starts again. There are several neurotransmitters in the body which are also involved in eating regulation. Ghrelin is a hormone which is released when the stomach is empty so it triggers eating. The second most important hormone is leptin and this is released from adipocytes, and the more fat a person has the more leptin is released and it acts as a satiety signal so stops food intake. Cummings et al (2004) did a study into the effects of ghrelin on people.
Discuss the importance of teeth in human nutrition Teeth perform mechanical digestion thus increasing the surface area of food for salivary amylase to work and for the enzymes of the stomach and small intestine to work more efficiently 2. Describe how food passes through the esophagus Food is pushed down the esophagus to the stomach through the process of peristalsis. Wave-like contractions alternate between contraction and relaxation to push the food through the entire digestive tract from the esophagus through the stomach, small intestine and large intestine. 3. Why would the enzymes in your mouth not work in your stomach and the enzymes in your stomach not work in your mouth?
In the body there are two main body systems one being the circulatory system and the other being the digestive system. The digestive system has four main stages these are ingestion, digestion, absorption and elimination. Ingestion starts at the mouth where the food enters the mouth and is chewed using the teeth in the mouth. The salivary glands in the mouth produce saliva which also helps to break food down and makes it easier to swallow. Once the food has been swallowed is goes down the oesophagus where the involuntary muscle movements help push the food to the stomach.