Human nutrition Details Flashcards
Importance of carbohydrates
Main source of energy for the body(provides long lasting energy)
Importance of fats and oils
-Insulation
-Stores energy
-Used as a fuel source
Importance of proteins
Helps build/repair body tissues
Importance of vitamin C
-Protects cells and improves/maintains healthy connective tissue, blood vessels, bones, cartilage and skin
-Needed for iron absorption
Importance of vitamin D
-Helps maintain healthy bones, teeth and muscles
-Needed for calcium absorption
Importance of calcium
-Needed for strong teeth and bones
-Involved in the clotting of bones
Importance of iron
-Used to make haemoglobin
-Helps transport oxygen around the body
Importance of fibre(roughage)
-Helps to keep the digestive system healthy(helps food to move through the stomach and the intestines)
-Helps to reduce constipation
Importance of water
Needed for chemical reactions to take place in cells
Cause of scurvy
Severe lack of vitamin C
Cause of rickets
Severe lack of vitamin D
Organs in the alimentary canal
-Mouth
-Oesophagus
-Stomach
-Small intestine(duodenum and ileum)
-Large intestine(colon, rectum and anus)
Associated organs of the digestive system
-Salivary glands
-Pancreas
-Liver
-Gall bladder
Purpose of physical digestion
Increases the surface area of food for the action of enzymes in chemical digestion
Function of molars
Grinding and chewing food
Function of pre-molars
Tearing and grinding food
Function of canines
Ripping and tearing food
Function of incisors
Biting off food pieces
Purpose of chemical digestion
Producing small soluble molecules that can be absorbed
Enzyme for starch
Amylase
Enzyme for protein
Protease
Enzyme for fats and oils
Lipase
Where amylase is produced
-Salivary glands
-Pancreas
-Small intestine
Where protease is produced
-Stomach
-Pancreas
-Small intestine
Where lipase is produced
-Pancreas
-Small intestine
Where amylase acts
-Mouth
-Duodenum
Where protease acts
-Stomach(pepsin)
-Duodenum(trypsin)
Where lipase acts
Duodenum
Function of hydrochloric acid in gastric juice
-Kills harmful microorganisms in food
-Provides an acidic pH for optimum enzyme activity
Function of bile
-Neutralises the acidic mixture of food and gastric juices entering the duodenum from the stomach to provide a suitable pH for enzyme action(bile is alkaline)
-Emulsifies fats and oils to increase the surface area for chemical digestion
Process of digestion of starch in the digestive system
-Amylase breaks down starch to maltose
-Maltase breaks down maltose to glucose on the membranes of the epithelium lining in the small intestine
Process of digestion of proteins in the digestive system
-Pepsin breaks down protein in the acidic conditions of the stomach
-Trypsin breaks down protein in the alkaline conditions of the small intestine
Where bile is made
Liver
Where bile is stored
Gall bladder
Region where nutrients are absorbed
Small intestine
Most water is absorbed in the small intestine, but some is also absorbed in the…
colon(of the large intestine)
Function of lacteal
Absorbs fatty acids and glycerol
Function of capillaries
Absorbs glucose and amino acids by diffusion
Features of epithelial lining
-One cell thick(to increase diffusion rate)
-Microvilli(to increase surface area even further)
Where gastric juice is produced
Stomach
Function of enamel
Covers the tooth and protects the tissue inside(very hard)
Features of dentine
-Found underneath the enamel
-Less hard than enamel
Features of pulp
Made of soft tissue which contains blood vessels and nerves
Features of cement
Covers the root of the tooth and stabilises it
Function of stomach
-Contains pepsin which breaks down proteins(in chemical digestion)
-Churns food to break it up more(in physical digestion)
Function of oesophagus
Allows food to pass from the mouth to the stomach(by peristalsis)
What happens at the duodenum
-Acidity(from the stomach) is neutralised
-Protease, lipase and amylase enzymes are secreted to break down molecules
What happens at the ileum
Products of digestion are absorbed into the blood
Function of the pancreas
Secretes pancreatic juices(which contain amylase, protease and lipase enzymes) into the small intestine
Function of liver
Produces bile
Function of gall bladder
Stores bile
What happens at the large intestine
Remaining salts and water are absorbed(most are absorbed in the small intestine)
