Digestive System Flashcards
5 digestion processes
1.Ingestion- taking in food and chewing and swallowing
2.Digestion- breakdown of food into smaller substances
3.Absorption- food is absorbed into the cells
4.Assimilation- absorbed food provides energy
5.Egestion- removal of undigested food
2 types of digestion
1.Mechanical digestion- chewing in the mouth, churning in the stomach and elimination of fats which helps to reduce the size of the food particles
2.Chemical digestion enzymes- digestive enzymes breakdown nutrients into small molecules such as salivary amylase in saliva
Digestive enzymes
-Are specific
-Substrates bind to the active site of the enzymes
-Enzymes break up the chemical bonds producing smaller molecules
IBS (irritable bowel syndrome)
-Symptoms- cramps, pains, excessive pooing, bloating, wind and diarrhoea
-Causes- abnormal peristalsis which is the contraction of the gut muscles, sensitivity, digestive issues and lifestyle factors
-Treatment- Imodium or laxatives, identifying certain foods and reducing stress
Digestion breaks down food
-Proteins into amino acids
-Fats into fatty acids
-Starch into glucose
Absorption
-Nutrients are absorption through the small intestine
-Villi create a large surface area for absorption
-Each villa has a blood capillary and a central vessel
-Glucose, amino acids and water soluble vitamins diffuse directly into the bloodstream
-Lipids are absorbed into the lacteals which merge to form lymphatic vessels
-Chyle- lymphatic fluid empties into the bloodstream via the thoracic duct in the chest
Journey to the liver
-Nutrients absorbed go directly into the bloodstream travel via the hepatic portal vein into the liver
-Fats end up at the liver via the lymphatic system
Liver
-Store some nutrients such as glucose and glycogen, fats and minerals such as iron
-The liver distributes the nutrients
-Produces bile which emulsifies lipids
Assimilation
-Movement of the digestive food molecules into the cells
-These are then used becoming a part of that cell
Coeliac disease
-Symptoms- indigestion, stomach pain, weight loss and tiredness
-Causes- autoimmune condition, often runs in families and a group of faulty genes cause this
-Explanation- the immune system produces antibodies which attack the gluten which causes damage to the villi which affects the bodies ability to absorb nutrients
-Treatments- avoidance of gluten, supplements, staying well and monitoring the illness
Gallstones
-Explanation- chemical imbalance of high levels of cholesterol and bilirubin which cause crystals to develop
-Symptoms- pain, excessive sweating, vomiting, jaundice and diarrhoea
-Causes- age 40 or older, obese people, high cholesterol, other conditions such as IBS and genetics
-Treatments- cholangiography which is where dye is injected into the gallbladder to revel where the stones are, lithotripsy where an endoscope sends shock waves to break the gallstones, keyhole surgery to remove the gallstones and lifestyles changes like having a balanced diet
Stomach
-Secretes acids and enzymes that digest food
Small intestine
-Absorbs nutrients and minerals
Large intestine
-Absorbs water from the undigested food
-Converts waste to poo
Gall bladder
-Stores bile from the liver and released it into the small intestine
Pancreas
-Makes insulin and hormones for digestion
-Regulates the blood sugars
-Produces enzymes that are transports to the duodenum
Pancreatic duct
-Small tube which allows for digestive juices to flow into the duodenum
Buccal cavity
-Where mechanical digestion takes place
-Tonge rolls the rood to the back of the throat
Duodenum (small intestine)
-Where further digestion occurs
-Sucrose is digested by sucrase into glucose and fructose
Duodenum (small intestine)
-Where further digestion occurs
-Sucrose is digested by sucrase into glucose and fructose
