Digestion system

• The bolus is a ball-like mixture of food and saliva that forms in the mouth during the process of chewing
• ingestion is when the food leaves the mouth
• mechanical and chemical are the two types of digestion
• mechanical digestion involves physically breaking down food substances into smaller particles
• Chemical digestion uses certain enzymes to break down nutrients
• mechanical digestion takes place in the mouth
• mechanical digestion in the oral cavity consists of grinding of food into smaller pieces by the teeth, called mastication
• the movement of the smooth muscles that helps makes food pass down the oesophagus is peristalsis
• peristalsis is wave-like contractions that move food through the oseophagus
• in the stomach there are gastric glands
• gastric glands produce gastric juice which contain enzyme gastric protease and hydrochloric acid
• the salivary glands, liver, gallbladder, and the pancreas are accessory organs for digestion
• the accessory organs for digestion aid the processes of ingestion, digestion and absorption
• the three secretions of the small intestine are ileum, duodenum and jejunum
• in the small intestine it breaks down food and absorb nutrients needed for the body
• A sphincter stops food escaping back up the oesophagus
• if the sphincter doesn't work the stomach contents go back up the oesophagus which is called reflux
• chyme is the mixture of food that has been broken down by the enzymes in the stomach
• the lining of the stomach is called the mucosa
• the lining of the small intestine has mucosa because for maximal absorption
• at the junction of the small and large intestine lies the ileocecal valve
• The ileocaecal valve can become stuck in an open or closed position which can lead to digestion being disrupted
• the lining of the large intestine is made of mucosa and submucosa
• the large intestine mostly absorbs water
• a condition that is caused by the failure to stop reflux of stomach contents is gastroesophageal reflux disease
• the symptoms of gastroesophageal reflux disease are heartburn, regurgitation, and chest pain
• a condition that affects the small intestine is celiac disease, which is an autoimmune disorder
• in celiac disease the lining of the small intestine is damaged and unable to absorb nutrients
• the types of enzymes are amylase, lipase, protease, and maltase
• amylase is produced in the salivary glands and pancreas
• lipase is produced in the pancreas, mouth and stomach
• protease is produced in the stomach, pancreas, and small intestine
• maltase is produced in the intestinal wall
• amylase breaks down starch
• protease breaks down protein and polypeptides
• the two products of the breakdown of lipids by lipase is fatty acids and glycerol
• the microbiome improves heart and brain health, weight control, reduce blood sugars
• the microbiome helps with digestion, the immune system, and vitamins
• What does peristalsis do


  Helps food pass down the oesophagus
• What are the accessory organs for digestion

  Salivary glands, liver, gallbladder and pancreas